From ba54d070ceb879f1ec899c3c4c3f7e75a1b0bfea Mon Sep 17 00:00:00 2001
From: dhwanish-3 <108540722+dhwanish-3@users.noreply.github.com>
Date: Sat, 21 Oct 2023 23:42:38 +0530
Subject: [PATCH 1/2] Stage 23 + 2 Assgns + rootfile can being modified

---
 Stage23/Assgn1/create.expl       |  14 +
 Stage23/Assgn1/create.xsm        | 137 ++++++++
 Stage23/Assgn2/delete.expl       |  23 ++
 Stage23/Assgn2/delete.xsm        | 168 ++++++++++
 Stage23/int15.spl                |  33 ++
 Stage23/int15.xsm                |  91 +++++
 Stage23/int4.spl                 | 159 +++++++++
 Stage23/int4.xsm                 | 532 ++++++++++++++++++++++++++++++
 Stage23/mod0.spl                 | 137 ++++++++
 Stage23/mod0.xsm                 | 350 ++++++++++++++++++++
 Stage23/mod4.spl                 |  96 ++++++
 Stage23/mod4.xsm                 | 149 +++++++++
 Stage23/mod7.spl                 | 203 ++++++++++++
 Stage23/mod7.xsm                 | 392 ++++++++++++++++++++++
 expl/assemblycode.xsm            | 549 ++++---------------------------
 xfs-interface/inodeusertable.txt | 128 +++----
 xfs-interface/rootfile.txt       |  78 ++---
 xfs-interface/stage23.sh         |  27 ++
 18 files changed, 2685 insertions(+), 581 deletions(-)
 create mode 100644 Stage23/Assgn1/create.expl
 create mode 100644 Stage23/Assgn1/create.xsm
 create mode 100644 Stage23/Assgn2/delete.expl
 create mode 100644 Stage23/Assgn2/delete.xsm
 create mode 100644 Stage23/int15.spl
 create mode 100644 Stage23/int15.xsm
 create mode 100644 Stage23/int4.spl
 create mode 100644 Stage23/int4.xsm
 create mode 100644 Stage23/mod0.spl
 create mode 100644 Stage23/mod0.xsm
 create mode 100644 Stage23/mod4.spl
 create mode 100644 Stage23/mod4.xsm
 create mode 100644 Stage23/mod7.spl
 create mode 100644 Stage23/mod7.xsm
 create mode 100644 xfs-interface/stage23.sh

diff --git a/Stage23/Assgn1/create.expl b/Stage23/Assgn1/create.expl
new file mode 100644
index 0000000..13a6cf7
--- /dev/null
+++ b/Stage23/Assgn1/create.expl
@@ -0,0 +1,14 @@
+int main() {
+    decl
+        int temp, permission;
+        str file;
+    enddecl
+    begin
+        temp = exposcall("Write", -2, "File Name:");
+        temp = exposcall("Read", -1, file);
+        temp = exposcall("Write", -2, "Permission:");
+        temp = exposcall("Read", -1, permission);
+        temp = exposcall("Create", file, permission);
+        return 0;
+    end
+}
\ No newline at end of file
diff --git a/Stage23/Assgn1/create.xsm b/Stage23/Assgn1/create.xsm
new file mode 100644
index 0000000..24eef80
--- /dev/null
+++ b/Stage23/Assgn1/create.xsm
@@ -0,0 +1,137 @@
+0
+2056
+0
+0
+0
+0
+0
+0
+MOV SP,4095
+MOV BP,4096
+PUSH R0
+CALL 2066
+INT 10
+PUSH BP
+MOV BP,SP
+PUSH R0
+PUSH R0
+PUSH R0
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"File Name:"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Read"
+PUSH R0
+MOV R0,-1
+PUSH R0
+MOV R1,BP
+MOV R0,3
+ADD R1,R0
+MOV R0,[R1]
+MOV R0,R1
+MOV R0,R0
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"Permission:"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Read"
+PUSH R0
+MOV R0,-1
+PUSH R0
+MOV R1,BP
+MOV R0,2
+ADD R1,R0
+MOV R0,[R1]
+MOV R0,R1
+MOV R0,R0
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Create"
+PUSH R0
+MOV R1,BP
+MOV R0,3
+ADD R1,R0
+MOV R0,[R1]
+MOV R0,R0
+PUSH R0
+MOV R2,BP
+MOV R1,2
+ADD R2,R1
+MOV R1,[R2]
+MOV R0,R1
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,0
+MOV R1,BP
+MOV R2,2
+SUB R1,R2
+MOV [R1],R0
+POP R0
+POP R0
+POP R0
+MOV BP,[SP]
+POP R0
+RET
diff --git a/Stage23/Assgn2/delete.expl b/Stage23/Assgn2/delete.expl
new file mode 100644
index 0000000..18ac487
--- /dev/null
+++ b/Stage23/Assgn2/delete.expl
@@ -0,0 +1,23 @@
+int main() {
+    decl
+        int temp;
+        str file;
+    enddecl
+    begin
+        temp = exposcall("Write", -2, "File Name:");
+        temp = exposcall("Read", -1, file);
+        temp = exposcall("Delete", file);
+        if(temp == 0) then
+            temp = exposcall("Write", -2, "Deleted");
+        else
+            if(temp == -1) then
+            temp = exposcall("Write", -2, "no permission");
+            else
+                if(temp == -2) then
+                    temp = exposcall("Write", -2, "File open");
+                endif;
+            endif;
+        endif;
+        return 0;
+    end
+}
\ No newline at end of file
diff --git a/Stage23/Assgn2/delete.xsm b/Stage23/Assgn2/delete.xsm
new file mode 100644
index 0000000..5985ea0
--- /dev/null
+++ b/Stage23/Assgn2/delete.xsm
@@ -0,0 +1,168 @@
+0
+2056
+0
+0
+0
+0
+0
+0
+MOV SP,4095
+MOV BP,4096
+PUSH R0
+CALL 2066
+INT 10
+PUSH BP
+MOV BP,SP
+PUSH R0
+PUSH R0
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"File Name:"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Read"
+PUSH R0
+MOV R0,-1
+PUSH R0
+MOV R1,BP
+MOV R0,2
+ADD R1,R0
+MOV R0,[R1]
+MOV R0,R1
+MOV R0,R0
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R0,"Delete"
+PUSH R0
+MOV R1,BP
+MOV R0,2
+ADD R1,R0
+MOV R0,[R1]
+MOV R0,R0
+PUSH R0
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+MOV R1,BP
+MOV R0,1
+ADD R1,R0
+MOV R0,[R1]
+MOV R1,0
+EQ R0,R1
+JZ R0,2250
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"Deleted"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+JMP 2356
+MOV R1,BP
+MOV R0,1
+ADD R1,R0
+MOV R0,[R1]
+MOV R1,-1
+EQ R0,R1
+JZ R0,2302
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"no permission"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
+MOV R2,BP
+MOV R1,1
+ADD R2,R1
+MOV [R2],R0
+JMP 2356
+MOV R1,BP
+MOV R0,1
+ADD R1,R0
+MOV R0,[R1]
+MOV R1,-2
+EQ R0,R1
+JZ R0,2356
+PUSH R0
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"File open"
+PUSH R0
+PUSH R0
+PUSH R0
+CALL 0
+SUB SP,5
+POP R0
+MOV R1,6
+MOV R2,SP
+ADD R2,R1
+MOV R1,[R2]
+MOV R3,BP
+MOV R2,1
+ADD R3,R2
+MOV [R3],R1
+MOV R0,0
+MOV R1,BP
+MOV R2,2
+SUB R1,R2
+MOV [R1],R0
+POP R0
+POP R0
+MOV BP,[SP]
+POP R0
+RET
diff --git a/Stage23/int15.spl b/Stage23/int15.spl
new file mode 100644
index 0000000..9eb6b3e
--- /dev/null
+++ b/Stage23/int15.spl
@@ -0,0 +1,33 @@
+[PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13] = SP;
+SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 11] * 512 - 1;
+
+[PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 9] = 21;
+
+if ([SYSTEM_STATUS_TABLE + 1] != 1 && [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 3] != 1) then
+    SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13];
+    [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 9] = 0;
+    ireturn;
+else
+    // inode table
+    R1 = 1;
+    R2 = [SYSTEM_STATUS_TABLE + 1];
+    R3 = 59;
+    R4 = 3;
+    call DEVICE_MANAGER;
+
+    // user table
+    R1 = 1;
+    R2 = [SYSTEM_STATUS_TABLE + 1];
+    R3 = 60;
+    R4 = 4;
+    call DEVICE_MANAGER;
+
+    // root file
+    R1 = 1;
+    R2 = [SYSTEM_STATUS_TABLE + 1];
+    R3 = 62;
+    R4 = 5;
+    call DEVICE_MANAGER;
+
+    halt;
+endif;
\ No newline at end of file
diff --git a/Stage23/int15.xsm b/Stage23/int15.xsm
new file mode 100644
index 0000000..0825dc6
--- /dev/null
+++ b/Stage23/int15.xsm
@@ -0,0 +1,91 @@
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 13
+MOV [R16], SP
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 11
+MOV R16, [R16]
+MUL R16, 512
+SUB R16, 1
+MOV SP, R16
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 9
+MOV [R16], 21
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R17, 1
+NE R16, R17
+MOV R17, 28672
+MOV R18, 29560
+ADD R18, 1
+MOV R18, [R18]
+MUL R18, 16
+ADD R17, R18
+ADD R17, 3
+MOV R17, [R17]
+MOV R18, 1
+NE R17, R18
+MUL R16, R17
+JZ R16, _L1
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 13
+MOV R16, [R16]
+MOV SP, R16
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 9
+MOV [R16], 0
+IRET
+JMP _L2
+_L1:
+MOV R1, 1
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R2, R16
+MOV R3, 59
+MOV R4, 3
+CALL 24576
+MOV R1, 1
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R2, R16
+MOV R3, 60
+MOV R4, 4
+CALL 24576
+MOV R1, 1
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R2, R16
+MOV R3, 62
+MOV R4, 5
+CALL 24576
+HALT
+_L2:
+HALT
\ No newline at end of file
diff --git a/Stage23/int4.spl b/Stage23/int4.spl
new file mode 100644
index 0000000..127eb92
--- /dev/null
+++ b/Stage23/int4.spl
@@ -0,0 +1,159 @@
+[PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13] = SP;
+
+alias userSP R0;
+userSP = SP;
+
+SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 11] * 512 - 1;
+
+alias sysCallNo R1;
+
+sysCallNo = [[PTBR + 2 * (userSP - 5) / 512] * 512 + (userSP - 5) % 512];
+
+alias returnAddress R10;
+
+returnAddress = [PTBR + 2 * (userSP - 1) / 512] * 512 + (userSP - 1) % 512;
+
+[PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 9] = sysCallNo;
+
+alias fileName R2;
+fileName = [[PTBR + 2 * (userSP - 4) / 512] * 512 + (userSP - 4) % 512];
+
+alias i R3;
+i = 0;
+alias fileFound R4;
+fileFound = 0;
+while (i < MAX_FILE_NUM) do
+    if ([INODE_TABLE + i * 16 + 1] == fileName) then
+        fileFound = 1;
+        break;
+    endif;
+    i = i + 1;
+endwhile;
+
+if (sysCallNo == 1) then // create
+    if (fileFound == 1) then
+        [returnAddress] = 0;
+        SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13];
+        [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 9] = 0;
+        ireturn;
+    endif;
+    alias permission R5;
+    permission = [[PTBR + 2 * (userSP - 3) / 512] * 512 + (userSP - 3) % 512];
+
+    i = 0;
+    while (i < MAX_FILE_NUM) do
+        if ([INODE_TABLE + i * 16 + 1] == -1) then
+            break;
+        endif;
+        i = i + 1;
+    endwhile;
+
+    if (i == MAX_FILE_NUM) then
+        [returnAddress] = -1;
+    else
+        alias inodeEntry R11;
+        inodeEntry = INODE_TABLE + i * 16;
+        alias userID R8;
+        userID = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 3];
+        
+        [inodeEntry + 0] = DATA;
+        [inodeEntry + 1] = fileName;
+        [inodeEntry + 2] = 0; // file size
+        [inodeEntry + 3] = userID;
+        [inodeEntry + 4] = permission;
+
+        [ROOT_FILE + i * 8 + 0] = fileName;
+        [ROOT_FILE + i * 8 + 1] = 9;
+        [ROOT_FILE + i * 8 + 2] = DATA;
+        [ROOT_FILE + i * 8 + 3] = [USER_TABLE + userID * 2];
+        [ROOT_FILE + i * 8 + 4] = permission;
+
+        [PROCESS_TABLE + i * 16 + 9] = 0;
+        [returnAddress] = 0;
+    endif;
+endif;
+
+if (sysCallNo == 4) then // Delete
+    if (fileFound == 0) then
+        [returnAddress] = 0;
+        SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13];
+        [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 9] = 0;
+        ireturn;
+    endif;
+    alias inodeEntry R11;
+    inodeEntry = INODE_TABLE + i * 16;
+    if ([inodeEntry + 0] != DATA) then 
+        [returnAddress] = -1;
+    else
+        if ([inodeEntry + 4] == EXCLUSIVE && [SYSTEM_STATUS_TABLE + 1] != 1 && [inodeEntry + 3] != [PROCESS_TABLE + i * 16 + 3]) then
+            [returnAddress] = -1;
+        else
+            multipush(R0, R1, R2, R3, R4, R11);
+            R1 = 4;
+            R2 = i;
+            R3 = [SYSTEM_STATUS_TABLE + 1];
+            call RESOURCE_MANAGER;
+            multipop(R0, R1, R2, R3, R4, R11);
+
+            if ([FILE_STATUS_TABLE + i * 4 + 1] != -1) then // file is open
+                multipush(R0, R1, R2, R3, R4, R11);
+                R1 = 5;
+                R2 = i;
+                R3 = [SYSTEM_STATUS_TABLE + 1];
+                call RESOURCE_MANAGER;
+                multipop(R0, R1, R2, R3, R4, R11);
+                [returnAddress] = -1;
+            else
+                alias blockNum R5;
+                blockNum = inodeEntry + 8;
+                alias limit R6;
+                limit = blockNum + 4;
+                while (blockNum < limit) do
+                    if ([blockNum] == -1) then
+                        break;
+                    endif;
+                    alias bufferIndex R7;
+                    bufferIndex = [blockNum] % MAX_BUFFER;
+                    if ([BUFFER_TABLE + bufferIndex * 4 + 0] == [blockNum] && [BUFFER_TABLE + bufferIndex * 4 + 1] == 1) then
+                        [BUFFER_TABLE + bufferIndex * 4 + 1] = 0;
+                    endif;
+
+                    multipush(R0, R1, R2, R3, R4, R5, R6, R7, R11);
+                    R1 = 4;
+                    R2 = [blockNum];
+                    R3 = [SYSTEM_STATUS_TABLE + 1];
+                    call MEMORY_MANAGER;
+                    multipop(R0, R1, R2, R3, R4, R5, R6, R7, R11);
+                    blockNum = blockNum + 1;
+                endwhile;
+
+                alias inodePages R8;
+                inodePages = inodeEntry;
+                limit = inodePages + 16;
+                while (inodePages < limit) do
+                    [inodePages] = -1;
+                    inodePages = inodePages + 1;
+                endwhile;
+
+                alias rootFile R8;
+                rootFile = ROOT_FILE + 8 * i;
+                limit = rootFile + 8;
+                while (rootFile < limit) do
+                    [rootFile] = -1;
+                    rootFile = rootFile + 1;
+                endwhile;
+
+                multipush(R10);
+                R1 = 5;
+                R2 = i;
+                R3 = [SYSTEM_STATUS_TABLE + 1];
+                call RESOURCE_MANAGER;
+                multipop(R10);
+                [returnAddress] = 0;
+            endif;
+        endif;
+    endif;
+endif;
+
+SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13];
+ireturn;
\ No newline at end of file
diff --git a/Stage23/int4.xsm b/Stage23/int4.xsm
new file mode 100644
index 0000000..13f98b9
--- /dev/null
+++ b/Stage23/int4.xsm
@@ -0,0 +1,532 @@
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R12, R16
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 13
+MOV [R16], SP
+MOV R0, SP
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 11
+MOV R16, [R16]
+MUL R16, 512
+SUB R16, 1
+MOV SP, R16
+MOV R16, 2
+MOV R17, R0
+SUB R17, 5
+MUL R16, R17
+DIV R16, 512
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R2, R16
+MOV R16, R0
+SUB R16, 5
+MOD R16, 512
+MOV R3, R16
+MOV R16, R2
+ADD R16, R3
+MOV R16, [R16]
+MOV R1, R16
+MOV R16, 2
+MOV R17, R0
+SUB R17, 1
+MUL R16, R17
+DIV R16, 512
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R10, R16
+MOV R16, R0
+SUB R16, 1
+MOD R16, 512
+MOV R3, R16
+MOV R16, R10
+ADD R16, R3
+MOV R10, R16
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 9
+MOV [R16], R1
+MOV R16, 1
+EQ R16, R1
+JZ R16, _L1
+MOV R16, 2
+MOV R17, R0
+SUB R17, 4
+MUL R16, R17
+DIV R16, 512
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R2, R16
+MOV R16, R0
+SUB R16, 4
+MOD R16, 512
+MOV R3, R16
+MOV R16, R2
+ADD R16, R3
+MOV R16, [R16]
+MOV R4, R16
+MOV R16, 2
+MOV R17, R0
+SUB R17, 3
+MUL R16, R17
+DIV R16, 512
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R2, R16
+MOV R16, R0
+SUB R16, 3
+MOD R16, 512
+MOV R3, R16
+MOV R16, R2
+ADD R16, R3
+MOV R16, [R16]
+MOV R5, R16
+MOV R6, 0
+MOV R7, 0
+_L3:
+MOV R16, 60
+GT R16, R6
+JZ R16, _L4
+MOV R16, 30208
+MOV R17, R6
+MUL R17, 16
+ADD R16, R17
+ADD R16, 1
+MOV R16, [R16]
+EQ R16, R4
+JZ R16, _L5
+MOV R7, 1
+JMP _L4
+JMP _L6
+_L5:
+_L6:
+MOV R16, R6
+ADD R16, 1
+MOV R6, R16
+JMP _L3
+_L4:
+MOV R16, 1
+EQ R16, R7
+JZ R16, _L7
+MOV [R10], 0
+JMP _L8
+_L7:
+MOV R6, 0
+_L9:
+MOV R16, 60
+GT R16, R6
+JZ R16, _L10
+MOV R16, 30208
+MOV R17, R6
+MUL R17, 16
+ADD R16, R17
+ADD R16, 1
+MOV R16, [R16]
+MOV R17, -1
+EQ R16, R17
+JZ R16, _L11
+JMP _L10
+JMP _L12
+_L11:
+_L12:
+MOV R16, R6
+ADD R16, 1
+MOV R6, R16
+JMP _L9
+_L10:
+MOV R16, 60
+EQ R16, R6
+JZ R16, _L13
+MOV [R10], -1
+JMP _L14
+_L13:
+MOV R16, 30208
+MOV R17, R6
+MUL R17, 16
+ADD R16, R17
+MOV R11, R16
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 3
+MOV R16, [R16]
+MOV R8, R16
+MOV R16, R11
+ADD R16, 0
+MOV [R16], 2
+MOV R16, R11
+ADD R16, 1
+MOV [R16], R4
+MOV R16, R11
+ADD R16, 2
+MOV [R16], 0
+MOV R16, R11
+ADD R16, 3
+MOV [R16], R8
+MOV R16, R11
+ADD R16, 4
+MOV [R16], R5
+MOV R16, 31744
+MOV R17, R6
+MUL R17, 8
+ADD R16, R17
+ADD R16, 0
+MOV [R16], R4
+MOV R16, 31744
+MOV R17, R6
+MUL R17, 8
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 0
+MOV R16, 31744
+MOV R17, R6
+MUL R17, 8
+ADD R16, R17
+ADD R16, 2
+MOV [R16], 2
+MOV R16, 31744
+MOV R17, R6
+MUL R17, 8
+ADD R16, R17
+ADD R16, 3
+MOV R17, 31168
+MOV R18, R8
+MUL R18, 2
+ADD R17, R18
+MOV R17, [R17]
+MOV [R16], R17
+MOV R16, 31744
+MOV R17, R6
+MUL R17, 8
+ADD R16, R17
+ADD R16, 4
+MOV [R16], R5
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 9
+MOV [R16], 0
+MOV [R10], 0
+_L14:
+_L8:
+JMP _L2
+_L1:
+_L2:
+MOV R16, 4
+EQ R16, R1
+JZ R16, _L15
+MOV R4, 0
+MOV R16, 2
+MOV R17, R0
+SUB R17, 4
+MUL R16, R17
+DIV R16, 512
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R17, R0
+SUB R17, 4
+MOD R17, 512
+ADD R16, R17
+MOV R16, [R16]
+MOV R5, R16
+_L17:
+MOV R16, 60
+GT R16, R4
+JZ R16, _L18
+MOV R16, 30208
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 1
+MOV R16, [R16]
+EQ R16, R5
+JZ R16, _L19
+JMP _L18
+JMP _L20
+_L19:
+_L20:
+MOV R16, R4
+ADD R16, 1
+MOV R4, R16
+JMP _L17
+_L18:
+MOV R16, 60
+EQ R16, R4
+JZ R16, _L21
+MOV [R10], 0
+JMP _L22
+_L21:
+MOV R16, 30208
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+MOV R11, R16
+MOV R16, R11
+ADD R16, 0
+MOV R16, [R16]
+MOV R17, 2
+NE R16, R17
+JZ R16, _L23
+MOV [R10], -1
+JMP _L24
+_L23:
+MOV R16, R11
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 0
+EQ R16, R17
+MOV R17, 1
+NE R17, R12
+MUL R16, R17
+MOV R17, R11
+ADD R17, 3
+MOV R17, [R17]
+MOV R18, 28672
+MOV R19, R4
+MUL R19, 16
+ADD R18, R19
+ADD R18, 3
+MOV R18, [R18]
+NE R17, R18
+MUL R16, R17
+JZ R16, _L25
+MOV [R10], -1
+JMP _L26
+_L25:
+PUSH R0
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+PUSH R5
+PUSH R10
+PUSH R11
+PUSH R12
+MOV R1, 4
+MOV R2, R4
+MOV R3, R12
+CALL 20480
+POP R12
+POP R11
+POP R10
+POP R5
+POP R4
+POP R3
+POP R2
+POP R1
+POP R0
+MOV R16, 29312
+MOV R17, R4
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV R16, [R16]
+MOV R17, -1
+NE R16, R17
+JZ R16, _L27
+PUSH R0
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+PUSH R5
+PUSH R10
+PUSH R11
+PUSH R12
+MOV R1, 5
+MOV R2, R4
+MOV R3, R12
+CALL 20480
+POP R12
+POP R11
+POP R10
+POP R5
+POP R4
+POP R3
+POP R2
+POP R1
+POP R0
+MOV [R10], -1
+JMP _L28
+_L27:
+MOV R16, R11
+ADD R16, 8
+MOV R6, R16
+MOV R16, R6
+ADD R16, 4
+MOV R7, R16
+_L29:
+MOV R16, R6
+LT R16, R7
+JZ R16, _L30
+MOV R16, R6
+MOV R16, [R16]
+MOV R17, -1
+EQ R16, R17
+JZ R16, _L31
+JMP _L30
+JMP _L32
+_L31:
+_L32:
+MOV R16, R6
+MOV R16, [R16]
+MOD R16, 4
+MOV R8, R16
+MOV R16, 30016
+MOV R17, R8
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV R16, [R16]
+MOV R17, R6
+MOV R17, [R17]
+EQ R16, R17
+MOV R17, 30016
+MOV R18, R8
+MUL R18, 4
+ADD R17, R18
+ADD R17, 1
+MOV R17, [R17]
+MOV R18, 1
+EQ R17, R18
+MUL R16, R17
+JZ R16, _L33
+MOV R16, 30016
+MOV R17, R8
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 0
+JMP _L34
+_L33:
+_L34:
+PUSH R0
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+PUSH R5
+PUSH R6
+PUSH R7
+PUSH R8
+PUSH R10
+PUSH R11
+PUSH R12
+MOV R1, 4
+MOV R16, R6
+MOV R16, [R16]
+MOV R2, R16
+MOV R3, R12
+CALL 22528
+POP R12
+POP R11
+POP R10
+POP R8
+POP R7
+POP R6
+POP R5
+POP R4
+POP R3
+POP R2
+POP R1
+POP R0
+MOV R16, R6
+ADD R16, 1
+MOV R6, R16
+JMP _L29
+_L30:
+MOV R8, R11
+MOV R16, R8
+ADD R16, 16
+MOV R7, R16
+_L35:
+MOV R16, R8
+LT R16, R7
+JZ R16, _L36
+MOV [R8], -1
+MOV R16, R8
+ADD R16, 1
+MOV R8, R16
+JMP _L35
+_L36:
+MOV R16, 31744
+MOV R17, R4
+MUL R17, 8
+ADD R16, R17
+MOV R8, R16
+MOV R16, R8
+ADD R16, 8
+MOV R7, R16
+_L37:
+MOV R16, R8
+LT R16, R7
+JZ R16, _L38
+MOV [R8], -1
+MOV R16, R8
+ADD R16, 1
+MOV R8, R16
+JMP _L37
+_L38:
+PUSH R0
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+PUSH R5
+PUSH R6
+PUSH R7
+PUSH R8
+PUSH R9
+PUSH R10
+PUSH R11
+PUSH R12
+MOV R1, 5
+MOV R2, R4
+MOV R3, R12
+CALL 20480
+POP R12
+POP R11
+POP R10
+POP R9
+POP R8
+POP R7
+POP R6
+POP R5
+POP R4
+POP R3
+POP R2
+POP R1
+POP R0
+MOV [R10], 0
+_L28:
+_L26:
+_L24:
+_L22:
+JMP _L16
+_L15:
+_L16:
+MOV R16, 28672
+MOV R17, R12
+MUL R17, 16
+ADD R16, R17
+ADD R16, 13
+MOV R16, [R16]
+MOV SP, R16
+IRET
+HALT
\ No newline at end of file
diff --git a/Stage23/mod0.spl b/Stage23/mod0.spl
new file mode 100644
index 0000000..8923e7f
--- /dev/null
+++ b/Stage23/mod0.spl
@@ -0,0 +1,137 @@
+alias functionNum R1;
+alias currentPID R2;
+
+// Acquire Disk
+if (functionNum == 3) then
+    while ([DISK_STATUS_TABLE] == 1) do
+        [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_DISK;
+        multipush(R1, R2);
+        call MOD_5;
+        multipop(R1, R2);
+    endwhile;
+    [DISK_STATUS_TABLE] = 1;
+    [DISK_STATUS_TABLE + 4] = currentPID;
+    return;
+endif;
+
+if (functionNum == 4) then // acquire inode
+    alias inodeNumber R2;
+    alias currentPID R3;
+
+    while ([FILE_STATUS_TABLE + inodeNumber * 4 + 0] != -1) do
+        [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_FILE;
+        [PROCESS_TABLE + currentPID * 16 + 5] = inodeNumber;
+        multipush(R1, R2, R3);
+        call SCHEDULER;
+        multipop(R1, R2, R3);
+    endwhile;
+
+    // file delete check
+    if ([INODE_TABLE + inodeNumber * 16 + 1] == -1) then
+        R0 = -1;
+    else 
+        [FILE_STATUS_TABLE + inodeNumber * 4 + 0] = currentPID;
+        R0 = 0;
+    endif; 
+endif;
+
+if (functionNum == 5) then // release inode
+    alias inodeNumber R2;
+    alias currentPID R3;
+
+    if ([FILE_STATUS_TABLE + inodeNumber * 4 + 0] == currentPID) then
+        [FILE_STATUS_TABLE + inodeNumber * 4 + 0] = -1;
+        alias i R4;
+        i = 0;
+        while (i < MAX_FILE_NUM) do
+            if ([PROCESS_TABLE + i * 16 + 4] == WAIT_FILE && [PROCESS_TABLE + i * 16 + 5] == inodeNumber) then
+                [PROCESS_TABLE + i * 16 + 4] = READY;
+            endif;
+            i = i + 1;
+        endwhile;
+        R0 = 0;
+    else
+        R0 = -1;
+    endif;
+endif;
+
+if (functionNum == 6) then // acquire semaphore
+    alias i R3;
+    i = 0;
+    while(i < MAX_SEM_COUNT && [SEMAPHORE_TABLE + 4 * i + 1] != 0) do
+        i = i + 1;
+    endwhile;
+
+    if (i == MAX_SEM_COUNT) then
+        R0 = -1;
+    else
+        [SEMAPHORE_TABLE + 4 * i] = -1;
+        [SEMAPHORE_TABLE + 4 * i + 1] = 1;
+        R0 = i;
+    endif;
+    return;
+endif;
+
+if (functionNum == 7) then // Release semaphore
+    alias semId R2;
+    alias currentPID R3;
+
+    if (currentPID == [SEMAPHORE_TABLE + semId * 4]) then
+        [SEMAPHORE_TABLE + semId * 4] = -1;
+        alias i R4;
+
+        i = 0;
+        while (i < 16) do
+            if ([PROCESS_TABLE + i * 16 + 4] == WAIT_SEMAPHORE && [PROCESS_TABLE + i * 16 + 5] == semId) then
+                [PROCESS_TABLE + i * 16 + 4] = READY;
+                [PROCESS_TABLE + i * 16 + 5] = -1;
+            endif;
+            i = i + 1;
+        endwhile;
+
+        [SEMAPHORE_TABLE + 4 * semId + 1] = [SEMAPHORE_TABLE + 4 * semId + 1] - 1;
+    endif;
+    return;
+endif;
+
+// Acquire Terminal
+if (functionNum == 8) then
+    while ([TERMINAL_STATUS_TABLE] != 0) do
+        [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_TERMINAL;
+        multipush(R1, R2);
+
+        call MOD_5;
+
+        multipop(R1, R2);
+    endwhile;
+
+    [TERMINAL_STATUS_TABLE] = 1;
+    [TERMINAL_STATUS_TABLE + 1] = currentPID;
+    return;
+endif;
+
+// Release Terminal
+if (functionNum == 9) then
+    if (currentPID != [TERMINAL_STATUS_TABLE + 1]) then
+        alias returnValue R0;
+        returnValue = -1;
+        return; 
+    else
+        [TERMINAL_STATUS_TABLE] = 0;
+        alias i R3;
+        i = 0;
+        while (i < 16) do
+            if ([PROCESS_TABLE + i * 16 + 4] == WAIT_TERMINAL) then
+                [PROCESS_TABLE + 16 * i + 4] = READY;
+            endif;
+            i = i + 1;
+        endwhile;
+        alias returnValue R0;
+        returnValue = 0;
+        return;
+    endif;
+else
+    alias returnValue R0;
+    returnValue = -1;
+    return;
+endif;
\ No newline at end of file
diff --git a/Stage23/mod0.xsm b/Stage23/mod0.xsm
new file mode 100644
index 0000000..6e15400
--- /dev/null
+++ b/Stage23/mod0.xsm
@@ -0,0 +1,350 @@
+MOV R16, 3
+EQ R16, R1
+JZ R16, _L1
+_L3:
+MOV R16, 29552
+MOV R16, [R16]
+MOV R17, 1
+EQ R16, R17
+JZ R16, _L4
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 5
+PUSH R1
+PUSH R2
+CALL 25600
+POP R2
+POP R1
+JMP _L3
+_L4:
+MOV [29552], 1
+MOV R16, 29552
+ADD R16, 4
+MOV [R16], R2
+RET
+JMP _L2
+_L1:
+_L2:
+MOV R16, 4
+EQ R16, R1
+JZ R16, _L5
+_L7:
+MOV R16, 29312
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV R16, [R16]
+MOV R17, -1
+NE R16, R17
+JZ R16, _L8
+MOV R16, 28672
+MOV R17, R3
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 6
+MOV R16, 28672
+MOV R17, R3
+MUL R17, 16
+ADD R16, R17
+ADD R16, 5
+MOV [R16], R2
+PUSH R1
+PUSH R2
+PUSH R3
+CALL 25600
+POP R3
+POP R2
+POP R1
+JMP _L7
+_L8:
+MOV R16, 30208
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 1
+MOV R16, [R16]
+MOV R17, -1
+EQ R16, R17
+JZ R16, _L9
+MOV R0, -1
+JMP _L10
+_L9:
+MOV R16, 29312
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV [R16], R3
+MOV R0, 0
+_L10:
+JMP _L6
+_L5:
+_L6:
+MOV R16, 5
+EQ R16, R1
+JZ R16, _L11
+MOV R16, 29312
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV R16, [R16]
+EQ R16, R3
+JZ R16, _L13
+MOV R16, 29312
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV [R16], -1
+MOV R4, 0
+_L15:
+MOV R16, 60
+GT R16, R4
+JZ R16, _L16
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 6
+EQ R16, R17
+MOV R17, 28672
+MOV R18, R4
+MUL R18, 16
+ADD R17, R18
+ADD R17, 5
+MOV R17, [R17]
+EQ R17, R2
+MUL R16, R17
+JZ R16, _L17
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 1
+JMP _L18
+_L17:
+_L18:
+MOV R16, R4
+ADD R16, 1
+MOV R4, R16
+JMP _L15
+_L16:
+MOV R0, 0
+JMP _L14
+_L13:
+MOV R0, -1
+_L14:
+JMP _L12
+_L11:
+_L12:
+MOV R16, 6
+EQ R16, R1
+JZ R16, _L19
+MOV R3, 0
+_L21:
+MOV R16, 32
+GT R16, R3
+MOV R17, 29056
+MOV R18, 4
+MUL R18, R3
+ADD R17, R18
+ADD R17, 1
+MOV R17, [R17]
+MOV R18, 0
+NE R17, R18
+MUL R16, R17
+JZ R16, _L22
+MOV R16, R3
+ADD R16, 1
+MOV R3, R16
+JMP _L21
+_L22:
+MOV R16, 32
+EQ R16, R3
+JZ R16, _L23
+MOV R0, -1
+JMP _L24
+_L23:
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R3
+ADD R16, R17
+MOV [R16], -1
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R3
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 1
+MOV R0, R3
+_L24:
+RET
+JMP _L20
+_L19:
+_L20:
+MOV R16, 7
+EQ R16, R1
+JZ R16, _L25
+MOV R16, 29056
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+MOV R16, [R16]
+EQ R16, R3
+JZ R16, _L27
+MOV R16, 29056
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+MOV [R16], -1
+MOV R4, 0
+_L29:
+MOV R16, 16
+GT R16, R4
+JZ R16, _L30
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 10
+EQ R16, R17
+MOV R17, 28672
+MOV R18, R4
+MUL R18, 16
+ADD R17, R18
+ADD R17, 5
+MOV R17, [R17]
+EQ R17, R2
+MUL R16, R17
+JZ R16, _L31
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 1
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 5
+MOV [R16], -1
+JMP _L32
+_L31:
+_L32:
+MOV R16, R4
+ADD R16, 1
+MOV R4, R16
+JMP _L29
+_L30:
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R2
+ADD R16, R17
+ADD R16, 1
+MOV R17, 29056
+MOV R18, 4
+MUL R18, R2
+ADD R17, R18
+ADD R17, 1
+MOV R17, [R17]
+SUB R17, 1
+MOV [R16], R17
+JMP _L28
+_L27:
+_L28:
+RET
+JMP _L26
+_L25:
+_L26:
+MOV R16, 8
+EQ R16, R1
+JZ R16, _L33
+_L35:
+MOV R16, 29568
+MOV R16, [R16]
+MOV R17, 0
+NE R16, R17
+JZ R16, _L36
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 8
+PUSH R1
+PUSH R2
+CALL 25600
+POP R2
+POP R1
+JMP _L35
+_L36:
+MOV [29568], 1
+MOV R16, 29568
+ADD R16, 1
+MOV [R16], R2
+RET
+JMP _L34
+_L33:
+_L34:
+MOV R16, 9
+EQ R16, R1
+JZ R16, _L37
+MOV R16, 29568
+ADD R16, 1
+MOV R16, [R16]
+NE R16, R2
+JZ R16, _L39
+MOV R0, -1
+RET
+JMP _L40
+_L39:
+MOV [29568], 0
+MOV R3, 0
+_L41:
+MOV R16, 16
+GT R16, R3
+JZ R16, _L42
+MOV R16, 28672
+MOV R17, R3
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 8
+EQ R16, R17
+JZ R16, _L43
+MOV R16, 28672
+MOV R17, 16
+MUL R17, R3
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 1
+JMP _L44
+_L43:
+_L44:
+MOV R16, R3
+ADD R16, 1
+MOV R3, R16
+JMP _L41
+_L42:
+MOV R0, 0
+RET
+_L40:
+JMP _L38
+_L37:
+MOV R0, -1
+RET
+_L38:
+HALT
\ No newline at end of file
diff --git a/Stage23/mod4.spl b/Stage23/mod4.spl
new file mode 100644
index 0000000..59f87ec
--- /dev/null
+++ b/Stage23/mod4.spl
@@ -0,0 +1,96 @@
+alias functionNum R1;
+alias currentPID R2;
+alias word R3;
+
+// Disk Store
+if (functionNum == 1) then
+    alias pageNumber R3;
+    alias blockNum R4;
+
+    multipush(R1, R2, R3, R4);
+    R1 = 3;
+    call RESOURCE_MANAGER;
+    multipop(R1, R2, R3, R4);
+
+    [DISK_STATUS_TABLE + 1] = 1;
+    [DISK_STATUS_TABLE + 2] = pageNumber;
+    [DISK_STATUS_TABLE + 3] = blockNum;
+
+    store(pageNumber, blockNum);
+
+    [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_DISK;
+    multipush(R1, R2, R3, R4);
+    call SCHEDULER;
+    multipop(R1, R2, R3, R4);
+endif;
+
+// Disk Load
+if (functionNum == 2) then
+    alias memoryPage R3;
+    alias diskBlock R4;
+    multipush(R1, R2, R3, R4);
+
+    R1 = 3;
+    R2 = currentPID;
+    call MOD_0;
+
+    multipop(R1, R2, R3, R4);
+
+    [DISK_STATUS_TABLE + 1] = 0;
+    [DISK_STATUS_TABLE + 2] = memoryPage;
+    [DISK_STATUS_TABLE + 3] = diskBlock;
+
+    load(memoryPage, diskBlock);
+    
+    [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_DISK;
+
+    call MOD_5;
+
+    return;
+endif;
+
+// Terminal Write
+if (functionNum == 3) then
+    multipush(R1, R2, R3);
+    functionNum = 8;
+
+    call MOD_0;
+
+    multipop(R1, R2, R3);
+
+    print word;
+
+    multipush(R1, R2, R3);
+
+    functionNum = 9;
+
+    call MOD_0;
+
+    multipop(R1, R2, R3);
+
+    return;
+endif;
+
+// Terminal Read
+if (functionNum == 4) then
+    multipush(R1, R2, R3);
+    functionNum = 8;
+
+    call MOD_0;
+
+    multipop(R1, R2, R3);
+
+    read;
+
+    [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_TERMINAL;
+
+    multipush(R1, R2, R3);
+
+    call MOD_5;
+
+    multipop(R1, R2, R3);
+
+    [[PTBR + 2 * (word / 512)] * 512 + (word % 512)] = [PROCESS_TABLE + currentPID * 16 + 8];
+    
+    return;
+endif;
\ No newline at end of file
diff --git a/Stage23/mod4.xsm b/Stage23/mod4.xsm
new file mode 100644
index 0000000..20e4bd9
--- /dev/null
+++ b/Stage23/mod4.xsm
@@ -0,0 +1,149 @@
+MOV R16, 1
+EQ R16, R1
+JZ R16, _L1
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+MOV R1, 3
+CALL 20480
+POP R4
+POP R3
+POP R2
+POP R1
+MOV R16, 29552
+ADD R16, 1
+MOV [R16], 1
+MOV R16, 29552
+ADD R16, 2
+MOV [R16], R3
+MOV R16, 29552
+ADD R16, 3
+MOV [R16], R4
+STORE R3, R4
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 5
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+CALL 25600
+POP R4
+POP R3
+POP R2
+POP R1
+JMP _L2
+_L1:
+_L2:
+MOV R16, 2
+EQ R16, R1
+JZ R16, _L3
+PUSH R1
+PUSH R2
+PUSH R3
+PUSH R4
+MOV R1, 3
+MOV R2, R2
+CALL 20480
+POP R4
+POP R3
+POP R2
+POP R1
+MOV R16, 29552
+ADD R16, 1
+MOV [R16], 0
+MOV R16, 29552
+ADD R16, 2
+MOV [R16], R3
+MOV R16, 29552
+ADD R16, 3
+MOV [R16], R4
+LOAD R3, R4
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 5
+CALL 25600
+RET
+JMP _L4
+_L3:
+_L4:
+MOV R16, 3
+EQ R16, R1
+JZ R16, _L5
+PUSH R1
+PUSH R2
+PUSH R3
+MOV R1, 8
+CALL 20480
+POP R3
+POP R2
+POP R1
+MOV R16, R3
+PORT P1, R16
+OUT
+PUSH R1
+PUSH R2
+PUSH R3
+MOV R1, 9
+CALL 20480
+POP R3
+POP R2
+POP R1
+RET
+JMP _L6
+_L5:
+_L6:
+MOV R16, 4
+EQ R16, R1
+JZ R16, _L7
+PUSH R1
+PUSH R2
+PUSH R3
+MOV R1, 8
+CALL 20480
+POP R3
+POP R2
+POP R1
+IN
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 8
+PUSH R1
+PUSH R2
+PUSH R3
+CALL 25600
+POP R3
+POP R2
+POP R1
+MOV R16, 2
+MOV R17, R3
+DIV R17, 512
+MUL R16, R17
+ADD R16, PTBR
+MOV R16, [R16]
+MUL R16, 512
+MOV R17, R3
+MOD R17, 512
+ADD R16, R17
+MOV R17, 28672
+MOV R18, R2
+MUL R18, 16
+ADD R17, R18
+ADD R17, 8
+MOV R17, [R17]
+MOV [R16], R17
+RET
+JMP _L8
+_L7:
+_L8:
+HALT
\ No newline at end of file
diff --git a/Stage23/mod7.spl b/Stage23/mod7.spl
new file mode 100644
index 0000000..9e72e4f
--- /dev/null
+++ b/Stage23/mod7.spl
@@ -0,0 +1,203 @@
+// exhandler
+loadi(2, 15);
+loadi(3, 16);
+
+// timer interrupt
+loadi(4, 17);
+loadi(5, 18);
+
+// write interrupt
+loadi(16, 29);
+loadi(17, 30);
+
+// int 10
+loadi(22, 35);
+loadi(23, 36);
+
+// int 8 (fork)
+loadi(18, 31);
+loadi(19, 32);
+
+// Library
+loadi(63, 13);
+loadi(64, 14);
+
+// init
+loadi(65, 7);
+loadi(66, 8);
+
+// module 5
+loadi(50, 63);
+loadi(51, 64);
+
+// module 0
+loadi(40, 53);
+loadi(41, 54);
+
+// module 4
+loadi(48, 61);
+loadi(49, 62);
+
+// console interrupt
+loadi(8, 21);
+loadi(9, 22);
+
+// int 6
+loadi(14, 27);
+loadi(15, 28);
+
+// int 9
+loadi(20, 33);
+loadi(21, 34);
+
+// int 11
+loadi(24, 37);
+loadi(25, 38);
+
+// int 13
+loadi(28, 41);
+loadi(29, 42);
+
+// int 14
+loadi(30, 43);
+loadi(31, 44);
+
+// int 15
+loadi(32, 45);
+loadi(33, 46);
+
+// module 1
+loadi(42, 55);
+loadi(43, 56);
+
+// module 2
+loadi(44, 57);
+loadi(45, 58);
+
+// inode user table
+loadi(59, 3);
+loadi(60, 4);
+
+// disk interrupt
+loadi(6, 19);
+loadi(7, 20);
+
+// int4
+loadi(10, 23);
+loadi(11, 24);
+
+// root file
+loadi(62, 5);
+
+// disk free list
+loadi(61, 2);
+
+// memory free list initialization
+alias i R0;
+i = 0;
+while (i < 128) do
+    if (i < 76) then
+        [MEMORY_FREE_LIST  + i] = 1;
+    else
+        [MEMORY_FREE_LIST + i] = 0;
+    endif;
+    i = i + 1;
+endwhile;
+
+[MEMORY_FREE_LIST + 76] = 1;
+[MEMORY_FREE_LIST + 77] = 1;
+[MEMORY_FREE_LIST + 78] = 1;
+[MEMORY_FREE_LIST + 79] = 1;
+[MEMORY_FREE_LIST + 80] = 1;
+[MEMORY_FREE_LIST + 81] = 1;
+[MEMORY_FREE_LIST + 82] = 1;
+
+PTBR = PAGE_TABLE_BASE + 20;
+PTLR = 10;
+
+[PTBR + 0] = 63;
+[PTBR + 1] = "0100";
+[PTBR + 2] = 64;
+[PTBR + 3] = "0100";
+[PTBR + 4] = 78;
+[PTBR + 5] = "0110";
+[PTBR + 6] = 79;
+[PTBR + 7] = "0110";
+[PTBR + 8] = 65;
+[PTBR + 9] = "0100";
+[PTBR + 10] = 66;
+[PTBR + 11] = "0100";
+[PTBR + 12] = -1;
+[PTBR + 13] = "0000";
+[PTBR + 14] = -1;
+[PTBR + 15] = "0000";
+[PTBR + 16] = 76;
+[PTBR + 17] = "0110";
+[PTBR + 18] = 77;
+[PTBR + 19] = "0110";
+
+[PROCESS_TABLE + 16 + 1] = 1;
+[PROCESS_TABLE + 16 + 3] = 1; // user id
+[PROCESS_TABLE + 16 + 11] = 80;
+[PROCESS_TABLE + 16 + 12] = 0;
+[PROCESS_TABLE + 16 + 13] = 8 * 512;
+[PROCESS_TABLE + 16 + 14] = PTBR;
+[PROCESS_TABLE + 16 + 15] = PTLR;
+[PROCESS_TABLE + 16 + 4] = CREATED;
+[76 * 512] = [65 * 512 + 1];
+
+// per-process resource table for init
+i = 1;
+while (i < 9) do
+    [([PROCESS_TABLE + 16 + 11] + 1) * 512 - 2 * i] = -1;
+    i = i + 1;
+endwhile;
+
+// disk map table initialization for init
+
+[DISK_MAP_TABLE + 10 + 2] = -1;
+[DISK_MAP_TABLE + 10 + 3] = -1;
+[DISK_MAP_TABLE + 10 + 4] = 7;
+[DISK_MAP_TABLE + 10 + 5] = 8;
+[DISK_MAP_TABLE + 10 + 6] = -1;
+[DISK_MAP_TABLE + 10 + 7] = -1;
+[DISK_MAP_TABLE + 10 + 8] = -1;
+[DISK_MAP_TABLE + 10 + 9] = -1;
+
+i = 2;
+while (i < 16) do
+    [PROCESS_TABLE + 16 * i + 4] = TERMINATED;
+    i = i + 1;
+endwhile;
+
+[TERMINAL_STATUS_TABLE] = 0;
+[DISK_STATUS_TABLE] = 0;
+[SYSTEM_STATUS_TABLE + 0] = 0;
+[SYSTEM_STATUS_TABLE + 2] = 45;
+[SYSTEM_STATUS_TABLE + 3] = 0;
+
+// initialization of semaphore table
+i = 0;
+while (i < MAX_SEM_COUNT) do
+    [SEMAPHORE_TABLE + i * 4] = -1;
+    [SEMAPHORE_TABLE + i * 4 + 1] = 0;
+    i = i + 1;
+endwhile;
+
+// initialization of file status table
+i = 0;
+while (i < MAX_FILE_NUM) do
+    [FILE_STATUS_TABLE + i * 4 + 0] = -1;
+    [FILE_STATUS_TABLE + i * 4 + 1] = -1;
+    i = i + 1;
+endwhile;
+
+// initialization of buffer table
+i = 0;
+while (i < MAX_BUFFER) do
+    [BUFFER_TABLE + i * 4 + 0] = -1;
+    [BUFFER_TABLE + i * 4 + 1] = 0;
+    [BUFFER_TABLE + i * 4 + 2] = -1;
+    i = i + 1;
+endwhile;
+return;
\ No newline at end of file
diff --git a/Stage23/mod7.xsm b/Stage23/mod7.xsm
new file mode 100644
index 0000000..f2dcd0d
--- /dev/null
+++ b/Stage23/mod7.xsm
@@ -0,0 +1,392 @@
+MOV R16, 2
+LOADI R16, 15
+MOV R16, 3
+LOADI R16, 16
+MOV R16, 4
+LOADI R16, 17
+MOV R16, 5
+LOADI R16, 18
+MOV R16, 16
+LOADI R16, 29
+MOV R16, 17
+LOADI R16, 30
+MOV R16, 22
+LOADI R16, 35
+MOV R16, 23
+LOADI R16, 36
+MOV R16, 18
+LOADI R16, 31
+MOV R16, 19
+LOADI R16, 32
+MOV R16, 63
+LOADI R16, 13
+MOV R16, 64
+LOADI R16, 14
+MOV R16, 65
+LOADI R16, 7
+MOV R16, 66
+LOADI R16, 8
+MOV R16, 50
+LOADI R16, 63
+MOV R16, 51
+LOADI R16, 64
+MOV R16, 40
+LOADI R16, 53
+MOV R16, 41
+LOADI R16, 54
+MOV R16, 48
+LOADI R16, 61
+MOV R16, 49
+LOADI R16, 62
+MOV R16, 8
+LOADI R16, 21
+MOV R16, 9
+LOADI R16, 22
+MOV R16, 14
+LOADI R16, 27
+MOV R16, 15
+LOADI R16, 28
+MOV R16, 20
+LOADI R16, 33
+MOV R16, 21
+LOADI R16, 34
+MOV R16, 24
+LOADI R16, 37
+MOV R16, 25
+LOADI R16, 38
+MOV R16, 28
+LOADI R16, 41
+MOV R16, 29
+LOADI R16, 42
+MOV R16, 30
+LOADI R16, 43
+MOV R16, 31
+LOADI R16, 44
+MOV R16, 32
+LOADI R16, 45
+MOV R16, 33
+LOADI R16, 46
+MOV R16, 42
+LOADI R16, 55
+MOV R16, 43
+LOADI R16, 56
+MOV R16, 44
+LOADI R16, 57
+MOV R16, 45
+LOADI R16, 58
+MOV R16, 59
+LOADI R16, 3
+MOV R16, 60
+LOADI R16, 4
+MOV R16, 6
+LOADI R16, 19
+MOV R16, 7
+LOADI R16, 20
+MOV R16, 10
+LOADI R16, 23
+MOV R16, 11
+LOADI R16, 24
+MOV R16, 62
+LOADI R16, 5
+MOV R16, 61
+LOADI R16, 2
+MOV R0, 0
+_L1:
+MOV R16, 128
+GT R16, R0
+JZ R16, _L2
+MOV R16, 76
+GT R16, R0
+JZ R16, _L3
+MOV R16, 29184
+ADD R16, R0
+MOV [R16], 1
+JMP _L4
+_L3:
+MOV R16, 29184
+ADD R16, R0
+MOV [R16], 0
+_L4:
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L1
+_L2:
+MOV R16, 29184
+ADD R16, 76
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 77
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 78
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 79
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 80
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 81
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 82
+MOV [R16], 1
+MOV R16, 29696
+ADD R16, 20
+MOV PTBR, R16
+MOV PTLR, 10
+MOV R16, PTBR
+ADD R16, 0
+MOV [R16], 63
+MOV R16, PTBR
+ADD R16, 1
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 2
+MOV [R16], 64
+MOV R16, PTBR
+ADD R16, 3
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 4
+MOV [R16], 78
+MOV R16, PTBR
+ADD R16, 5
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 6
+MOV [R16], 79
+MOV R16, PTBR
+ADD R16, 7
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 8
+MOV [R16], 65
+MOV R16, PTBR
+ADD R16, 9
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 10
+MOV [R16], 66
+MOV R16, PTBR
+ADD R16, 11
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 12
+MOV [R16], -1
+MOV R16, PTBR
+ADD R16, 13
+MOV [R16], "0000"
+MOV R16, PTBR
+ADD R16, 14
+MOV [R16], -1
+MOV R16, PTBR
+ADD R16, 15
+MOV [R16], "0000"
+MOV R16, PTBR
+ADD R16, 16
+MOV [R16], 76
+MOV R16, PTBR
+ADD R16, 17
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 18
+MOV [R16], 77
+MOV R16, PTBR
+ADD R16, 19
+MOV [R16], "0110"
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 1
+MOV [R16], 1
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 3
+MOV [R16], 1
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 11
+MOV [R16], 80
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 12
+MOV [R16], 0
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 13
+MOV R17, 8
+MUL R17, 512
+MOV [R16], R17
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 14
+MOV [R16], PTBR
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 15
+MOV [R16], PTLR
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 4
+MOV [R16], 3
+MOV R16, 76
+MUL R16, 512
+MOV R17, 65
+MUL R17, 512
+ADD R17, 1
+MOV R17, [R17]
+MOV [R16], R17
+MOV R0, 1
+_L5:
+MOV R16, 9
+GT R16, R0
+JZ R16, _L6
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 11
+MOV R16, [R16]
+ADD R16, 1
+MUL R16, 512
+MOV R17, 2
+MUL R17, R0
+SUB R16, R17
+MOV [R16], -1
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L5
+_L6:
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 2
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 3
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 4
+MOV [R16], 7
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 5
+MOV [R16], 8
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 6
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 7
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 8
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 9
+MOV [R16], -1
+MOV R0, 2
+_L7:
+MOV R16, 16
+GT R16, R0
+JZ R16, _L8
+MOV R16, 28672
+MOV R17, 16
+MUL R17, R0
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 4
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L7
+_L8:
+MOV [29568], 0
+MOV [29552], 0
+MOV R16, 29560
+ADD R16, 0
+MOV [R16], 0
+MOV R16, 29560
+ADD R16, 2
+MOV [R16], 45
+MOV R16, 29560
+ADD R16, 3
+MOV [R16], 0
+MOV R0, 0
+_L9:
+MOV R16, 32
+GT R16, R0
+JZ R16, _L10
+MOV R16, 29056
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+MOV [R16], -1
+MOV R16, 29056
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 0
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L9
+_L10:
+MOV R0, 0
+_L11:
+MOV R16, 60
+GT R16, R0
+JZ R16, _L12
+MOV R16, 29312
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV [R16], -1
+MOV R16, 29312
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV [R16], -1
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L11
+_L12:
+MOV R0, 0
+_L13:
+MOV R16, 4
+GT R16, R0
+JZ R16, _L14
+MOV R16, 30016
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 0
+MOV [R16], -1
+MOV R16, 30016
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 0
+MOV R16, 30016
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 2
+MOV [R16], -1
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L13
+_L14:
+RET
+HALT
\ No newline at end of file
diff --git a/expl/assemblycode.xsm b/expl/assemblycode.xsm
index 913e235..5985ea0 100644
--- a/expl/assemblycode.xsm
+++ b/expl/assemblycode.xsm
@@ -6,426 +6,117 @@
 0
 0
 0
-MOV SP,4096
-MOV BP,4097
+MOV SP,4095
+MOV BP,4096
 PUSH R0
-CALL 2826
+CALL 2066
 INT 10
 PUSH BP
 MOV BP,SP
 PUSH R0
 PUSH R0
+MOV R0,"Write"
 PUSH R0
+MOV R0,-2
 PUSH R0
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,-1
-NE R0,R1
-MOV R1,1
-JZ R0,2122
-MOV R3,BP
-MOV R4,2
-SUB R3,R4
-MOV R4,1
-SUB R3,R4
-MOV R2,[R3]
-MOV R3,2
-ADD R3,R2
-MOV R2,[R3]
-MOV R3,-1
-NE R2,R3
-MOV R1,R2
-MUL R0,R1
-JZ R0,2424
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,1
-SUB R2,R3
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV [R3],R1
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,1
-SUB R2,R3
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,2
-ADD R3,R2
-MOV [R3],R1
-MOV R2,BP
-MOV R1,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,-1
-NE R1,R2
-JZ R1,2268
-MOV R2,BP
-MOV R1,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,2
-ADD R3,R2
-MOV [R3],R1
-MOV R2,BP
-MOV R1,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,-1
-NE R1,R2
-JZ R1,2266
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV R2,[R3]
-MOV R3,2
-ADD R3,R2
-MOV R2,[R3]
-MOV R4,BP
-MOV R3,1
-ADD R4,R3
-MOV [R4],R2
-MOV R3,BP
-MOV R2,2
-ADD R3,R2
-MOV R2,[R3]
-MOV R3,2
-ADD R3,R2
-MOV R2,[R3]
-MOV R4,BP
-MOV R3,2
-ADD R4,R3
-MOV [R4],R2
-JMP 2172
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,3
-ADD R2,R1
-MOV [R2],R0
-MOV R1,BP
-MOV R0,1
-ADD R1,R0
-MOV R0,[R1]
-MOV R1,2
-ADD R1,R0
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,4
-ADD R2,R1
-MOV [R2],R0
-MOV R0,-1
-MOV R2,BP
-MOV R1,1
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R1,R2
-MOV [R1],R0
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-PUSH R0
-PUSH R0
-CALL 2066
-POP R0
-POP R1
-MOV R2,BP
-MOV R1,3
-ADD R2,R1
-MOV [R2],R0
-MOV R1,BP
-MOV R0,4
-ADD R1,R0
-MOV R0,[R1]
+MOV R0,"File Name:"
 PUSH R0
 PUSH R0
-CALL 2066
-POP R0
-POP R1
-MOV R2,BP
-MOV R1,4
-ADD R2,R1
-MOV [R2],R0
-MOV R1,BP
-MOV R0,4
-ADD R1,R0
-MOV R0,[R1]
 PUSH R0
-MOV R1,BP
-MOV R0,3
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
 ADD R1,R0
 MOV R0,[R1]
-PUSH R0
-PUSH R0
-CALL 2458
-POP R0
-POP R1
-POP R1
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV [R1],R0
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV [R1],R0
-POP R0
-POP R0
-POP R0
-POP R0
-MOV BP,[SP]
-POP R0
-RET
-PUSH BP
-MOV BP,SP
-PUSH R0
-MOV R0,-1
 MOV R2,BP
 MOV R1,1
 ADD R2,R1
 MOV [R2],R0
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,-1
-EQ R0,R1
-JZ R0,2512
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,2
-SUB R2,R3
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV [R3],R1
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,2
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,-1
-EQ R0,R1
-JZ R0,2550
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,1
-SUB R2,R3
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV [R3],R1
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,-1
-NE R0,R1
-MOV R1,1
-JZ R0,2588
-MOV R3,BP
-MOV R4,2
-SUB R3,R4
-MOV R4,2
-SUB R3,R4
-MOV R2,[R3]
-MOV R3,-1
-NE R2,R3
-MOV R1,R2
-MUL R0,R1
-JZ R0,2802
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,1
-SUB R2,R3
-MOV R1,[R2]
-MOV R2,1
-ADD R2,R1
-MOV R1,[R2]
-MOV R3,BP
-MOV R4,2
-SUB R3,R4
-MOV R4,2
-SUB R3,R4
-MOV R2,[R3]
-MOV R3,1
-ADD R3,R2
-MOV R2,[R3]
-LE R1,R2
-JZ R1,2720
-MOV R2,BP
-MOV R3,2
-SUB R2,R3
-MOV R3,1
-SUB R2,R3
-MOV R1,[R2]
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV [R3],R1
+MOV R0,"Read"
 PUSH R0
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,2
-SUB R1,R2
-MOV R0,[R1]
+MOV R0,-1
 PUSH R0
 MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,2
+MOV R0,2
 ADD R1,R0
 MOV R0,[R1]
+MOV R0,R1
+MOV R0,R0
 PUSH R0
 PUSH R0
-CALL 2458
-POP R1
-POP R0
-POP R0
-POP R0
-MOV R3,BP
-MOV R2,1
-ADD R3,R2
-MOV R2,[R3]
-MOV R3,2
-ADD R3,R2
-MOV R2,[R3]
-MOV R2,R3
-MOV [R2],R1
-JMP 2802
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,2
-SUB R1,R2
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
 MOV R0,[R1]
 MOV R2,BP
 MOV R1,1
 ADD R2,R1
 MOV [R2],R0
+MOV R0,"Delete"
+PUSH R0
 MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,2
-SUB R1,R2
-MOV R0,[R1]
-MOV R1,2
+MOV R0,2
 ADD R1,R0
 MOV R0,[R1]
+MOV R0,R0
 PUSH R0
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV R2,1
-SUB R1,R2
-MOV R0,[R1]
 PUSH R0
 PUSH R0
-CALL 2458
-POP R0
-POP R1
-POP R1
+PUSH R0
+CALL 0
+SUB SP,5
+MOV R0,5
+MOV R1,SP
+ADD R1,R0
+MOV R0,[R1]
 MOV R2,BP
 MOV R1,1
 ADD R2,R1
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R1,R2
-MOV [R1],R0
+MOV [R2],R0
 MOV R1,BP
 MOV R0,1
 ADD R1,R0
 MOV R0,[R1]
-MOV R1,BP
-MOV R2,2
-SUB R1,R2
-MOV [R1],R0
-POP R0
-MOV BP,[SP]
-POP R0
-RET
-PUSH BP
-MOV BP,SP
-PUSH R0
+MOV R1,0
+EQ R0,R1
+JZ R0,2250
+MOV R0,"Write"
 PUSH R0
+MOV R0,-2
 PUSH R0
+MOV R0,"Deleted"
 PUSH R0
-MOV R0,"Heapset"
 PUSH R0
-ADD SP,3
 PUSH R0
 CALL 0
 SUB SP,5
-MOV R1,BP
-MOV R0,1
+MOV R0,5
+MOV R1,SP
 ADD R1,R0
-MOV [R1],R0
-MOV R0,-1
-MOV [4096],R0
-MOV R0,0
+MOV R0,[R1]
 MOV R2,BP
-MOV R1,2
+MOV R1,1
 ADD R2,R1
 MOV [R2],R0
+JMP 2356
 MOV R1,BP
-MOV R0,2
+MOV R0,1
 ADD R1,R0
 MOV R0,[R1]
-MOV R1,64
-LT R0,R1
-JZ R0,3074
-MOV R0,"Alloc"
+MOV R1,-1
+EQ R0,R1
+JZ R0,2302
+MOV R0,"Write"
+PUSH R0
+MOV R0,-2
+PUSH R0
+MOV R0,"no permission"
 PUSH R0
-MOV R0,8
 PUSH R0
-ADD SP,2
 PUSH R0
 CALL 0
 SUB SP,5
@@ -434,142 +125,44 @@ MOV R1,SP
 ADD R1,R0
 MOV R0,[R1]
 MOV R2,BP
-MOV R1,3
-ADD R2,R1
-MOV [R2],R0
-MOV R0,64
-MOV R2,BP
-MOV R1,2
-ADD R2,R1
-MOV R1,[R2]
-SUB R0,R1
-MOV R2,BP
-MOV R1,3
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,1
-ADD R2,R1
-MOV R1,[R2]
-MOV R1,R2
-MOV [R1],R0
-MOV R0,-1
-MOV R2,BP
-MOV R1,3
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R1,R2
-MOV [R1],R0
-MOV R0,[4096]
-MOV R1,-1
-EQ R0,R1
-JZ R0,3004
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-MOV [4096],R0
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,4
-ADD R2,R1
-MOV [R2],R0
-JMP 3052
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,4
-ADD R2,R1
-MOV R1,[R2]
-MOV R2,2
-ADD R2,R1
-MOV R1,[R2]
-MOV R1,R2
-MOV [R1],R0
-MOV R1,BP
-MOV R0,4
-ADD R1,R0
-MOV R0,[R1]
-MOV R1,2
-ADD R1,R0
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,4
-ADD R2,R1
-MOV [R2],R0
-MOV R1,BP
-MOV R0,2
-ADD R1,R0
-MOV R0,[R1]
 MOV R1,1
-ADD R0,R1
-MOV R2,BP
-MOV R1,2
-ADD R2,R1
-MOV [R2],R0
-JMP 2872
-MOV R0,[4096]
-PUSH R0
-PUSH R0
-CALL 2066
-POP R0
-POP R1
-MOV [4096],R0
-MOV R0,[4096]
-MOV R2,BP
-MOV R1,3
 ADD R2,R1
 MOV [R2],R0
+JMP 2356
 MOV R1,BP
-MOV R0,3
+MOV R0,1
 ADD R1,R0
 MOV R0,[R1]
-MOV R1,-1
-NE R0,R1
-JZ R0,3166
+MOV R1,-2
+EQ R0,R1
+JZ R0,2356
+PUSH R0
 MOV R0,"Write"
 PUSH R0
 MOV R0,-2
 PUSH R0
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-MOV R1,1
-ADD R1,R0
-MOV R0,[R1]
+MOV R0,"File open"
+PUSH R0
+PUSH R0
 PUSH R0
-ADD SP,2
 CALL 0
 SUB SP,5
-MOV R1,BP
-MOV R0,3
-ADD R1,R0
-MOV R0,[R1]
-MOV R1,2
-ADD R1,R0
-MOV R0,[R1]
-MOV R2,BP
-MOV R1,3
+POP R0
+MOV R1,6
+MOV R2,SP
 ADD R2,R1
-MOV [R2],R0
-JMP 3098
-MOV R0,1
+MOV R1,[R2]
+MOV R3,BP
+MOV R2,1
+ADD R3,R2
+MOV [R3],R1
+MOV R0,0
 MOV R1,BP
 MOV R2,2
 SUB R1,R2
 MOV [R1],R0
 POP R0
 POP R0
-POP R0
-POP R0
 MOV BP,[SP]
 POP R0
 RET
diff --git a/xfs-interface/inodeusertable.txt b/xfs-interface/inodeusertable.txt
index 6834614..0e94179 100644
--- a/xfs-interface/inodeusertable.txt
+++ b/xfs-interface/inodeusertable.txt
@@ -30,13 +30,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
+3
+prime.xsm
+272
 0
 -1
 -1
 -1
 -1
+70
 -1
 -1
 -1
@@ -44,15 +46,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+odd.xsm
+144
 0
 -1
 -1
 -1
 -1
+71
 -1
 -1
 -1
@@ -60,31 +62,31 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+exec.xsm
+1516
 0
 -1
 -1
 -1
 -1
+72
+73
+74
 -1
 -1
 -1
 -1
 -1
--1
--1
--1
--1
--1
--1
+3
+list.xsm
+508
 0
 -1
 -1
 -1
 -1
+75
 -1
 -1
 -1
@@ -92,15 +94,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+pid.xsm
+130
 0
 -1
 -1
 -1
 -1
+76
 -1
 -1
 -1
@@ -108,15 +110,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+fork3.xsm
+180
 0
 -1
 -1
 -1
 -1
+77
 -1
 -1
 -1
@@ -124,31 +126,31 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+test4.xsm
+990
 0
 -1
 -1
 -1
 -1
+78
+79
 -1
 -1
 -1
 -1
 -1
 -1
--1
--1
--1
--1
--1
+3
+parent.xsm
+280
 0
 -1
 -1
 -1
 -1
+80
 -1
 -1
 -1
@@ -156,15 +158,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+child.xsm
+328
 0
 -1
 -1
 -1
 -1
+81
 -1
 -1
 -1
@@ -172,47 +174,47 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+con.xsm
+1930
 0
 -1
 -1
 -1
 -1
+82
+83
+84
+85
 -1
 -1
 -1
 -1
--1
--1
--1
--1
--1
--1
--1
+3
+seq.xsm
+1150
 0
 -1
 -1
 -1
 -1
+86
+87
+88
 -1
 -1
 -1
 -1
 -1
--1
--1
--1
--1
--1
--1
+3
+create.xsm
+274
 0
 -1
 -1
 -1
 -1
+89
 -1
 -1
 -1
@@ -220,15 +222,15 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+3
+delete.xsm
+336
 0
 -1
 -1
 -1
 -1
+90
 -1
 -1
 -1
@@ -236,11 +238,11 @@ even.xsm
 -1
 -1
 -1
--1
--1
--1
--1
+2
+hari.dat
 0
+1
+1
 -1
 -1
 -1
@@ -256,8 +258,6 @@ even.xsm
 -1
 -1
 -1
-0
--1
 -1
 -1
 -1
diff --git a/xfs-interface/rootfile.txt b/xfs-interface/rootfile.txt
index 8d4d61d..377f8c2 100644
--- a/xfs-interface/rootfile.txt
+++ b/xfs-interface/rootfile.txt
@@ -14,105 +14,105 @@ even.xsm
 -1
 -1
 -1
--1
-0
--1
--1
--1
--1
--1
--1
--1
-0
--1
--1
--1
--1
--1
--1
--1
-0
--1
--1
--1
--1
--1
--1
--1
-0
--1
--1
--1
+prime.xsm
+272
+3
 -1
 -1
 -1
 -1
-0
--1
 -1
+odd.xsm
+144
+3
 -1
 -1
 -1
 -1
 -1
-0
+exec.xsm
+1516
+3
 -1
 -1
 -1
 -1
 -1
+list.xsm
+508
+3
 -1
 -1
-0
 -1
 -1
 -1
+pid.xsm
+130
+3
 -1
 -1
 -1
 -1
-0
 -1
+fork3.xsm
+180
+3
 -1
 -1
 -1
 -1
 -1
+test4.xsm
+990
+3
 -1
-0
 -1
 -1
 -1
 -1
+parent.xsm
+280
+3
 -1
 -1
 -1
-0
 -1
 -1
+child.xsm
+328
+3
 -1
 -1
 -1
 -1
 -1
-0
+con.xsm
+1930
+3
 -1
 -1
 -1
 -1
 -1
+seq.xsm
+1150
+3
 -1
 -1
-0
 -1
 -1
 -1
+create.xsm
+274
+3
 -1
 -1
 -1
 -1
-0
 -1
+delete.xsm
+336
+3
 -1
 -1
 -1
diff --git a/xfs-interface/stage23.sh b/xfs-interface/stage23.sh
new file mode 100644
index 0000000..b902a08
--- /dev/null
+++ b/xfs-interface/stage23.sh
@@ -0,0 +1,27 @@
+load --os $HOME/myexpos/Stage13/os_startup.xsm
+load --init $HOME/myexpos/Stage21/Assgn1/shell2.xsm
+load --idle $HOME/myexpos/Stage14/idle.xsm
+load --int=10 $HOME/myexpos/Stage20/exit.xsm
+load --int=11 $HOME/myexpos/Stage21/int11.xsm
+load --int=13 $HOME/myexpos/Stage22/int13.xsm
+load --int=14 $HOME/myexpos/Stage22/int14.xsm
+load --int=15 $HOME/myexpos/Stage23/int15.xsm
+load --int=9 $HOME/myexpos/Stage19/int9.xsm
+load --int=8 $HOME/myexpos/Stage22/fork.xsm
+load --exhandler $HOME/myexpos/Stage21/exhandler.xsm
+load --int=7 $HOME/myexpos/Stage15/int7.xsm
+load --int=6 $HOME/myexpos/Stage16/int6.xsm
+load --int=4 $HOME/myexpos/Stage23/int4.xsm
+load --int=disk $HOME/myexpos/Stage18/int2.xsm
+load --int=console $HOME/myexpos/Stage16/console_int.xsm
+load --module 5 $HOME/myexpos/Stage20/scheduler.xsm
+load --module 7 $HOME/myexpos/Stage23/mod7.xsm
+load --module 0 $HOME/myexpos/Stage23/mod0.xsm
+load --module 1 $HOME/myexpos/Stage22/mod1.xsm
+load --module 2 $HOME/myexpos/Stage19/module_2.xsm
+load --module 4 $HOME/myexpos/Stage23/mod4.xsm
+load --int=timer $HOME/myexpos/Stage14/timer.xsm
+rm create.xsm
+load --exec $HOME/myexpos/Stage23/Assgn1/create.xsm
+rm delete.xsm
+load --exec $HOME/myexpos/Stage23/Assgn2/delete.xsm
\ No newline at end of file

From 5671fa02e4f579dde83d8e17dca5c9fd61ff81b6 Mon Sep 17 00:00:00 2001
From: dhwanish-3 <108540722+dhwanish-3@users.noreply.github.com>
Date: Mon, 23 Oct 2023 21:35:52 +0530
Subject: [PATCH 2/2] Stage 22 Max memory done*

---
 Stage22/Assgn2/int15.spl   |  11 ++
 Stage22/Assgn2/int15.xsm   |  34 ++++
 Stage22/Assgn2/mod0.spl    |  98 +++++++++++
 Stage22/Assgn2/mod0.xsm    | 239 ++++++++++++++++++++++++++
 Stage22/Assgn2/mod5.spl    |  50 ++++++
 Stage22/Assgn2/mod5.xsm    | 113 ++++++++++++
 Stage22/Assgn2/mod7.spl    | 182 ++++++++++++++++++++
 Stage22/Assgn2/mod7.xsm    | 341 +++++++++++++++++++++++++++++++++++++
 Stage22/Assgn2/timer.spl   |  36 ++++
 Stage22/Assgn2/timer.xsm   |  87 ++++++++++
 xfs-interface/stage22_2.sh |  32 ++++
 11 files changed, 1223 insertions(+)
 create mode 100644 Stage22/Assgn2/int15.spl
 create mode 100644 Stage22/Assgn2/int15.xsm
 create mode 100644 Stage22/Assgn2/mod0.spl
 create mode 100644 Stage22/Assgn2/mod0.xsm
 create mode 100644 Stage22/Assgn2/mod5.spl
 create mode 100644 Stage22/Assgn2/mod5.xsm
 create mode 100644 Stage22/Assgn2/mod7.spl
 create mode 100644 Stage22/Assgn2/mod7.xsm
 create mode 100644 Stage22/Assgn2/timer.spl
 create mode 100644 Stage22/Assgn2/timer.xsm
 create mode 100644 xfs-interface/stage22_2.sh

diff --git a/Stage22/Assgn2/int15.spl b/Stage22/Assgn2/int15.spl
new file mode 100644
index 0000000..54b25f6
--- /dev/null
+++ b/Stage22/Assgn2/int15.spl
@@ -0,0 +1,11 @@
+alias taskManager R0;
+taskManager = SYSTEM_STATUS_TABLE + 24;
+print "contextSwitches:-";
+print [taskManager];
+print "------------";
+print "maxMemUsage:-";
+print [taskManager + 1];
+print "------------";
+print "diskAccesses:-";
+print [taskManager + 2];
+halt;
\ No newline at end of file
diff --git a/Stage22/Assgn2/int15.xsm b/Stage22/Assgn2/int15.xsm
new file mode 100644
index 0000000..ff3915e
--- /dev/null
+++ b/Stage22/Assgn2/int15.xsm
@@ -0,0 +1,34 @@
+MOV R16, 29560
+ADD R16, 24
+MOV R0, R16
+MOV R16, "contextSwitches:-"
+PORT P1, R16
+OUT
+MOV R16, R0
+MOV R16, [R16]
+PORT P1, R16
+OUT
+MOV R16, "------------"
+PORT P1, R16
+OUT
+MOV R16, "maxMemUsage:-"
+PORT P1, R16
+OUT
+MOV R16, R0
+ADD R16, 1
+MOV R16, [R16]
+PORT P1, R16
+OUT
+MOV R16, "------------"
+PORT P1, R16
+OUT
+MOV R16, "diskAccesses:-"
+PORT P1, R16
+OUT
+MOV R16, R0
+ADD R16, 2
+MOV R16, [R16]
+PORT P1, R16
+OUT
+HALT
+HALT
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod0.spl b/Stage22/Assgn2/mod0.spl
new file mode 100644
index 0000000..3361a78
--- /dev/null
+++ b/Stage22/Assgn2/mod0.spl
@@ -0,0 +1,98 @@
+alias functionNum R1;
+alias currentPID R2;
+
+// Acquire Disk
+if (functionNum == 3) then
+    while ([DISK_STATUS_TABLE] == 1) do
+        [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_DISK;
+        multipush(R1, R2);
+        call MOD_5;
+        multipop(R1, R2);
+    endwhile;
+    // disk accesses
+    [SYSTEM_STATUS_TABLE + 26] = [SYSTEM_STATUS_TABLE + 26] + 1;
+    [DISK_STATUS_TABLE] = 1;
+    [DISK_STATUS_TABLE + 4] = currentPID;
+    return;
+endif;
+
+if (functionNum == 6) then // acquire semaphore
+    alias i R3;
+    i = 0;
+    while(i < MAX_SEM_COUNT && [SEMAPHORE_TABLE + 4 * i + 1] != 0) do
+        i = i + 1;
+    endwhile;
+
+    if (i == MAX_SEM_COUNT) then
+        R0 = -1;
+    else
+        [SEMAPHORE_TABLE + 4 * i] = -1;
+        [SEMAPHORE_TABLE + 4 * i + 1] = 1;
+        R0 = i;
+    endif;
+    return;
+endif;
+
+if (functionNum == 7) then // Release semaphore
+    alias semId R2;
+    alias currentPID R3;
+
+    if (currentPID == [SEMAPHORE_TABLE + semId * 4]) then
+        [SEMAPHORE_TABLE + semId * 4] = -1;
+        alias i R4;
+
+        i = 0;
+        while (i < 16) do
+            if ([PROCESS_TABLE + i * 16 + 4] == WAIT_SEMAPHORE && [PROCESS_TABLE + i * 16 + 5] == semId) then
+                [PROCESS_TABLE + i * 16 + 4] = READY;
+                [PROCESS_TABLE + i * 16 + 5] = -1;
+            endif;
+            i = i + 1;
+        endwhile;
+
+        [SEMAPHORE_TABLE + 4 * semId + 1] = [SEMAPHORE_TABLE + 4 * semId + 1] - 1;
+    endif;
+    return;
+endif;
+
+// Acquire Terminal
+if (functionNum == 8) then
+    while ([TERMINAL_STATUS_TABLE] != 0) do
+        [PROCESS_TABLE + currentPID * 16 + 4] = WAIT_TERMINAL;
+        multipush(R1, R2);
+
+        call MOD_5;
+
+        multipop(R1, R2);
+    endwhile;
+
+    [TERMINAL_STATUS_TABLE] = 1;
+    [TERMINAL_STATUS_TABLE + 1] = currentPID;
+    return;
+endif;
+
+// Release Terminal
+if (functionNum == 9) then
+    if (currentPID != [TERMINAL_STATUS_TABLE + 1]) then
+        alias returnValue R0;
+        returnValue = -1;
+        return; 
+    else
+        [TERMINAL_STATUS_TABLE] = 0;
+        alias i R3;
+        i = 0;
+        while (i < 16) do
+            if ([PROCESS_TABLE + i * 16 + 4] == WAIT_TERMINAL) then
+                [PROCESS_TABLE + 16 * i + 4] = READY;
+            endif;
+            i = i + 1;
+        endwhile;
+        alias returnValue R0;
+        returnValue = 0;
+        return;
+    endif;
+else
+    alias returnValue R0;
+    returnValue = -1;
+    return;
+endif;
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod0.xsm b/Stage22/Assgn2/mod0.xsm
new file mode 100644
index 0000000..c59328a
--- /dev/null
+++ b/Stage22/Assgn2/mod0.xsm
@@ -0,0 +1,239 @@
+MOV R16, 3
+EQ R16, R1
+JZ R16, _L1
+_L3:
+MOV R16, 29552
+MOV R16, [R16]
+MOV R17, 1
+EQ R16, R17
+JZ R16, _L4
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 5
+PUSH R1
+PUSH R2
+CALL 25600
+POP R2
+POP R1
+JMP _L3
+_L4:
+MOV R16, 29560
+ADD R16, 26
+MOV R17, 29560
+ADD R17, 26
+MOV R17, [R17]
+ADD R17, 1
+MOV [R16], R17
+MOV [29552], 1
+MOV R16, 29552
+ADD R16, 4
+MOV [R16], R2
+RET
+JMP _L2
+_L1:
+_L2:
+MOV R16, 6
+EQ R16, R1
+JZ R16, _L5
+MOV R3, 0
+_L7:
+MOV R16, 32
+GT R16, R3
+MOV R17, 29056
+MOV R18, 4
+MUL R18, R3
+ADD R17, R18
+ADD R17, 1
+MOV R17, [R17]
+MOV R18, 0
+NE R17, R18
+MUL R16, R17
+JZ R16, _L8
+MOV R16, R3
+ADD R16, 1
+MOV R3, R16
+JMP _L7
+_L8:
+MOV R16, 32
+EQ R16, R3
+JZ R16, _L9
+MOV R0, -1
+JMP _L10
+_L9:
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R3
+ADD R16, R17
+MOV [R16], -1
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R3
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 1
+MOV R0, R3
+_L10:
+RET
+JMP _L6
+_L5:
+_L6:
+MOV R16, 7
+EQ R16, R1
+JZ R16, _L11
+MOV R16, 29056
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+MOV R16, [R16]
+EQ R16, R3
+JZ R16, _L13
+MOV R16, 29056
+MOV R17, R2
+MUL R17, 4
+ADD R16, R17
+MOV [R16], -1
+MOV R4, 0
+_L15:
+MOV R16, 16
+GT R16, R4
+JZ R16, _L16
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 10
+EQ R16, R17
+MOV R17, 28672
+MOV R18, R4
+MUL R18, 16
+ADD R17, R18
+ADD R17, 5
+MOV R17, [R17]
+EQ R17, R2
+MUL R16, R17
+JZ R16, _L17
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 1
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+ADD R16, 5
+MOV [R16], -1
+JMP _L18
+_L17:
+_L18:
+MOV R16, R4
+ADD R16, 1
+MOV R4, R16
+JMP _L15
+_L16:
+MOV R16, 29056
+MOV R17, 4
+MUL R17, R2
+ADD R16, R17
+ADD R16, 1
+MOV R17, 29056
+MOV R18, 4
+MUL R18, R2
+ADD R17, R18
+ADD R17, 1
+MOV R17, [R17]
+SUB R17, 1
+MOV [R16], R17
+JMP _L14
+_L13:
+_L14:
+RET
+JMP _L12
+_L11:
+_L12:
+MOV R16, 8
+EQ R16, R1
+JZ R16, _L19
+_L21:
+MOV R16, 29568
+MOV R16, [R16]
+MOV R17, 0
+NE R16, R17
+JZ R16, _L22
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 8
+PUSH R1
+PUSH R2
+CALL 25600
+POP R2
+POP R1
+JMP _L21
+_L22:
+MOV [29568], 1
+MOV R16, 29568
+ADD R16, 1
+MOV [R16], R2
+RET
+JMP _L20
+_L19:
+_L20:
+MOV R16, 9
+EQ R16, R1
+JZ R16, _L23
+MOV R16, 29568
+ADD R16, 1
+MOV R16, [R16]
+NE R16, R2
+JZ R16, _L25
+MOV R0, -1
+RET
+JMP _L26
+_L25:
+MOV [29568], 0
+MOV R3, 0
+_L27:
+MOV R16, 16
+GT R16, R3
+JZ R16, _L28
+MOV R16, 28672
+MOV R17, R3
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R17, 8
+EQ R16, R17
+JZ R16, _L29
+MOV R16, 28672
+MOV R17, 16
+MUL R17, R3
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 1
+JMP _L30
+_L29:
+_L30:
+MOV R16, R3
+ADD R16, 1
+MOV R3, R16
+JMP _L27
+_L28:
+MOV R0, 0
+RET
+_L26:
+JMP _L24
+_L23:
+MOV R0, -1
+RET
+_L24:
+HALT
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod5.spl b/Stage22/Assgn2/mod5.spl
new file mode 100644
index 0000000..04b7ab1
--- /dev/null
+++ b/Stage22/Assgn2/mod5.spl
@@ -0,0 +1,50 @@
+alias currentPID R0;
+alias process_table_entry R1;
+
+currentPID = [SYSTEM_STATUS_TABLE + 1];
+process_table_entry = PROCESS_TABLE + 16 * currentPID;
+
+multipush(BP);
+
+[process_table_entry + 12] = SP % 512;
+[process_table_entry + 14] = PTBR;
+[process_table_entry + 15] = PTLR;
+
+alias i R2;
+alias state R3;
+alias newPID R4;
+
+newPID = 0;
+i = currentPID + 1;
+while (i < 16) do
+    state = [PROCESS_TABLE + i * 16 + 4];
+    if (state == READY || state == CREATED) then
+        newPID = i;
+        break;
+    endif;
+    i = i + 1;
+endwhile;
+
+// context switches
+[SYSTEM_STATUS_TABLE + 24] = [SYSTEM_STATUS_TABLE + 24] + 1;
+
+process_table_entry = PROCESS_TABLE + (newPID * 16);
+SP = [process_table_entry + 11] * 512 + [process_table_entry + 12];
+PTBR = [process_table_entry + 14];
+PTLR = [process_table_entry + 15];
+
+[SYSTEM_STATUS_TABLE + 1] = newPID;
+
+if (state == CREATED) then
+    SP = [process_table_entry + 13];
+    BP = [[process_table_entry + 11] * 512];
+    [process_table_entry + 4] = RUNNING;
+    [process_table_entry + 9] = 0; // mode flag
+    ireturn;
+endif;
+
+[process_table_entry + 4] = RUNNING;
+
+multipop(BP);
+
+return;
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod5.xsm b/Stage22/Assgn2/mod5.xsm
new file mode 100644
index 0000000..75f2e04
--- /dev/null
+++ b/Stage22/Assgn2/mod5.xsm
@@ -0,0 +1,113 @@
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R0, R16
+MOV R16, 28672
+MOV R17, 16
+MUL R17, R0
+ADD R16, R17
+MOV R1, R16
+PUSH BP
+MOV R16, R1
+ADD R16, 12
+MOV R17, SP
+MOD R17, 512
+MOV [R16], R17
+MOV R16, R1
+ADD R16, 14
+MOV [R16], PTBR
+MOV R16, R1
+ADD R16, 15
+MOV [R16], PTLR
+MOV R4, 0
+MOV R16, R0
+ADD R16, 1
+MOV R2, R16
+_L1:
+MOV R16, 16
+GT R16, R2
+JZ R16, _L2
+MOV R16, 28672
+MOV R17, R2
+MUL R17, 16
+ADD R16, R17
+ADD R16, 4
+MOV R16, [R16]
+MOV R3, R16
+MOV R16, 1
+EQ R16, R3
+MOV R17, 3
+EQ R17, R3
+ADD R16, R17
+JZ R16, _L3
+MOV R4, R2
+JMP _L2
+JMP _L4
+_L3:
+_L4:
+MOV R16, R2
+ADD R16, 1
+MOV R2, R16
+JMP _L1
+_L2:
+MOV R16, 29560
+ADD R16, 24
+MOV R17, 29560
+ADD R17, 24
+MOV R17, [R17]
+ADD R17, 1
+MOV [R16], R17
+MOV R16, 28672
+MOV R17, R4
+MUL R17, 16
+ADD R16, R17
+MOV R1, R16
+MOV R16, R1
+ADD R16, 11
+MOV R16, [R16]
+MUL R16, 512
+MOV R17, R1
+ADD R17, 12
+MOV R17, [R17]
+ADD R16, R17
+MOV SP, R16
+MOV R16, R1
+ADD R16, 14
+MOV R16, [R16]
+MOV PTBR, R16
+MOV R16, R1
+ADD R16, 15
+MOV R16, [R16]
+MOV PTLR, R16
+MOV R16, 29560
+ADD R16, 1
+MOV [R16], R4
+MOV R16, 3
+EQ R16, R3
+JZ R16, _L5
+MOV R16, R1
+ADD R16, 13
+MOV R16, [R16]
+MOV SP, R16
+MOV R16, R1
+ADD R16, 11
+MOV R16, [R16]
+MUL R16, 512
+MOV R16, [R16]
+MOV BP, R16
+MOV R16, R1
+ADD R16, 4
+MOV [R16], 2
+MOV R16, R1
+ADD R16, 9
+MOV [R16], 0
+IRET
+JMP _L6
+_L5:
+_L6:
+MOV R16, R1
+ADD R16, 4
+MOV [R16], 2
+POP BP
+RET
+HALT
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod7.spl b/Stage22/Assgn2/mod7.spl
new file mode 100644
index 0000000..ffd4268
--- /dev/null
+++ b/Stage22/Assgn2/mod7.spl
@@ -0,0 +1,182 @@
+// exhandler
+loadi(2, 15);
+loadi(3, 16);
+
+// timer interrupt
+loadi(4, 17);
+loadi(5, 18);
+
+// write interrupt
+loadi(16, 29);
+loadi(17, 30);
+
+// int 10
+loadi(22, 35);
+loadi(23, 36);
+
+// int 8 (fork)
+loadi(18, 31);
+loadi(19, 32);
+
+// Library
+loadi(63, 13);
+loadi(64, 14);
+
+// init
+loadi(65, 7);
+loadi(66, 8);
+
+// module 5
+loadi(50, 63);
+loadi(51, 64);
+
+// module 0
+loadi(40, 53);
+loadi(41, 54);
+
+// module 4
+loadi(48, 61);
+loadi(49, 62);
+
+// console interrupt
+loadi(8, 21);
+loadi(9, 22);
+
+// int 6
+loadi(14, 27);
+loadi(15, 28);
+
+// int 9
+loadi(20, 33);
+loadi(21, 34);
+
+// int 11
+loadi(24, 37);
+loadi(25, 38);
+
+// int 13
+loadi(28, 41);
+loadi(29, 42);
+
+// int 14
+loadi(30, 43);
+loadi(31, 44);
+
+// int 15
+loadi(32, 45);
+loadi(33, 46);
+
+// module 1
+loadi(42, 55);
+loadi(43, 56);
+
+// module 2
+loadi(44, 57);
+loadi(45, 58);
+
+// inode user table
+loadi(59, 3);
+loadi(60, 4);
+
+// disk interrupt
+loadi(6, 19);
+loadi(7, 20);
+
+// disk free list
+loadi(61, 2);
+
+// memory free list initialization
+alias i R0;
+i = 0;
+while (i < 128) do
+    if (i < 76) then
+        [MEMORY_FREE_LIST  + i] = 1;
+    else
+        [MEMORY_FREE_LIST + i] = 0;
+    endif;
+    i = i + 1;
+endwhile;
+
+[MEMORY_FREE_LIST + 76] = 1;
+[MEMORY_FREE_LIST + 77] = 1;
+[MEMORY_FREE_LIST + 78] = 1;
+[MEMORY_FREE_LIST + 79] = 1;
+[MEMORY_FREE_LIST + 80] = 1;
+[MEMORY_FREE_LIST + 81] = 1;
+[MEMORY_FREE_LIST + 82] = 1;
+
+PTBR = PAGE_TABLE_BASE + 20;
+PTLR = 10;
+
+[PTBR + 0] = 63;
+[PTBR + 1] = "0100";
+[PTBR + 2] = 64;
+[PTBR + 3] = "0100";
+[PTBR + 4] = 78;
+[PTBR + 5] = "0110";
+[PTBR + 6] = 79;
+[PTBR + 7] = "0110";
+[PTBR + 8] = 65;
+[PTBR + 9] = "0100";
+[PTBR + 10] = 66;
+[PTBR + 11] = "0100";
+[PTBR + 12] = -1;
+[PTBR + 13] = "0000";
+[PTBR + 14] = -1;
+[PTBR + 15] = "0000";
+[PTBR + 16] = 76;
+[PTBR + 17] = "0110";
+[PTBR + 18] = 77;
+[PTBR + 19] = "0110";
+
+[PROCESS_TABLE + 16 + 1] = 1;
+[PROCESS_TABLE + 16 + 11] = 80;
+[PROCESS_TABLE + 16 + 12] = 0;
+[PROCESS_TABLE + 16 + 13] = 8 * 512;
+[PROCESS_TABLE + 16 + 14] = PTBR;
+[PROCESS_TABLE + 16 + 15] = PTLR;
+[PROCESS_TABLE + 16 + 4] = CREATED;
+[76 * 512] = [65 * 512 + 1];
+
+// per-process resource table for init
+i = 1;
+while (i < 9) do
+    [([PROCESS_TABLE + 16 + 11] + 1) * 512 - 2 * i] = -1;
+    i = i + 1;
+endwhile;
+
+// disk map table initialization for init
+
+[DISK_MAP_TABLE + 10 + 2] = -1;
+[DISK_MAP_TABLE + 10 + 3] = -1;
+[DISK_MAP_TABLE + 10 + 4] = 7;
+[DISK_MAP_TABLE + 10 + 5] = 8;
+[DISK_MAP_TABLE + 10 + 6] = -1;
+[DISK_MAP_TABLE + 10 + 7] = -1;
+[DISK_MAP_TABLE + 10 + 8] = -1;
+[DISK_MAP_TABLE + 10 + 9] = -1;
+
+i = 2;
+while (i < 16) do
+    [PROCESS_TABLE + 16 * i + 4] = TERMINATED;
+    i = i + 1;
+endwhile;
+
+[TERMINAL_STATUS_TABLE] = 0;
+[DISK_STATUS_TABLE] = 0;
+[SYSTEM_STATUS_TABLE + 0] = 0;
+[SYSTEM_STATUS_TABLE + 2] = 45;
+[SYSTEM_STATUS_TABLE + 3] = 0;
+[SYSTEM_STATUS_TABLE + 24] = 0; // context switches
+[SYSTEM_STATUS_TABLE + 25] = 0; // max memory usage
+[SYSTEM_STATUS_TABLE + 26] = 0; // disk accesses
+
+// initialization of semaphore table
+i = 0;
+while (i < MAX_SEM_COUNT) do
+    [SEMAPHORE_TABLE + i * 4] = -1;
+    [SEMAPHORE_TABLE + i * 4 + 1] = 0;
+    i = i + 1;
+endwhile;
+
+return;
\ No newline at end of file
diff --git a/Stage22/Assgn2/mod7.xsm b/Stage22/Assgn2/mod7.xsm
new file mode 100644
index 0000000..2b9ffa2
--- /dev/null
+++ b/Stage22/Assgn2/mod7.xsm
@@ -0,0 +1,341 @@
+MOV R16, 2
+LOADI R16, 15
+MOV R16, 3
+LOADI R16, 16
+MOV R16, 4
+LOADI R16, 17
+MOV R16, 5
+LOADI R16, 18
+MOV R16, 16
+LOADI R16, 29
+MOV R16, 17
+LOADI R16, 30
+MOV R16, 22
+LOADI R16, 35
+MOV R16, 23
+LOADI R16, 36
+MOV R16, 18
+LOADI R16, 31
+MOV R16, 19
+LOADI R16, 32
+MOV R16, 63
+LOADI R16, 13
+MOV R16, 64
+LOADI R16, 14
+MOV R16, 65
+LOADI R16, 7
+MOV R16, 66
+LOADI R16, 8
+MOV R16, 50
+LOADI R16, 63
+MOV R16, 51
+LOADI R16, 64
+MOV R16, 40
+LOADI R16, 53
+MOV R16, 41
+LOADI R16, 54
+MOV R16, 48
+LOADI R16, 61
+MOV R16, 49
+LOADI R16, 62
+MOV R16, 8
+LOADI R16, 21
+MOV R16, 9
+LOADI R16, 22
+MOV R16, 14
+LOADI R16, 27
+MOV R16, 15
+LOADI R16, 28
+MOV R16, 20
+LOADI R16, 33
+MOV R16, 21
+LOADI R16, 34
+MOV R16, 24
+LOADI R16, 37
+MOV R16, 25
+LOADI R16, 38
+MOV R16, 28
+LOADI R16, 41
+MOV R16, 29
+LOADI R16, 42
+MOV R16, 30
+LOADI R16, 43
+MOV R16, 31
+LOADI R16, 44
+MOV R16, 32
+LOADI R16, 45
+MOV R16, 33
+LOADI R16, 46
+MOV R16, 42
+LOADI R16, 55
+MOV R16, 43
+LOADI R16, 56
+MOV R16, 44
+LOADI R16, 57
+MOV R16, 45
+LOADI R16, 58
+MOV R16, 59
+LOADI R16, 3
+MOV R16, 60
+LOADI R16, 4
+MOV R16, 6
+LOADI R16, 19
+MOV R16, 7
+LOADI R16, 20
+MOV R16, 61
+LOADI R16, 2
+MOV R0, 0
+_L1:
+MOV R16, 128
+GT R16, R0
+JZ R16, _L2
+MOV R16, 76
+GT R16, R0
+JZ R16, _L3
+MOV R16, 29184
+ADD R16, R0
+MOV [R16], 1
+JMP _L4
+_L3:
+MOV R16, 29184
+ADD R16, R0
+MOV [R16], 0
+_L4:
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L1
+_L2:
+MOV R16, 29184
+ADD R16, 76
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 77
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 78
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 79
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 80
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 81
+MOV [R16], 1
+MOV R16, 29184
+ADD R16, 82
+MOV [R16], 1
+MOV R16, 29696
+ADD R16, 20
+MOV PTBR, R16
+MOV PTLR, 10
+MOV R16, PTBR
+ADD R16, 0
+MOV [R16], 63
+MOV R16, PTBR
+ADD R16, 1
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 2
+MOV [R16], 64
+MOV R16, PTBR
+ADD R16, 3
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 4
+MOV [R16], 78
+MOV R16, PTBR
+ADD R16, 5
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 6
+MOV [R16], 79
+MOV R16, PTBR
+ADD R16, 7
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 8
+MOV [R16], 65
+MOV R16, PTBR
+ADD R16, 9
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 10
+MOV [R16], 66
+MOV R16, PTBR
+ADD R16, 11
+MOV [R16], "0100"
+MOV R16, PTBR
+ADD R16, 12
+MOV [R16], -1
+MOV R16, PTBR
+ADD R16, 13
+MOV [R16], "0000"
+MOV R16, PTBR
+ADD R16, 14
+MOV [R16], -1
+MOV R16, PTBR
+ADD R16, 15
+MOV [R16], "0000"
+MOV R16, PTBR
+ADD R16, 16
+MOV [R16], 76
+MOV R16, PTBR
+ADD R16, 17
+MOV [R16], "0110"
+MOV R16, PTBR
+ADD R16, 18
+MOV [R16], 77
+MOV R16, PTBR
+ADD R16, 19
+MOV [R16], "0110"
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 1
+MOV [R16], 1
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 11
+MOV [R16], 80
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 12
+MOV [R16], 0
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 13
+MOV R17, 8
+MUL R17, 512
+MOV [R16], R17
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 14
+MOV [R16], PTBR
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 15
+MOV [R16], PTLR
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 4
+MOV [R16], 3
+MOV R16, 76
+MUL R16, 512
+MOV R17, 65
+MUL R17, 512
+ADD R17, 1
+MOV R17, [R17]
+MOV [R16], R17
+MOV R0, 1
+_L5:
+MOV R16, 9
+GT R16, R0
+JZ R16, _L6
+MOV R16, 28672
+ADD R16, 16
+ADD R16, 11
+MOV R16, [R16]
+ADD R16, 1
+MUL R16, 512
+MOV R17, 2
+MUL R17, R0
+SUB R16, R17
+MOV [R16], -1
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L5
+_L6:
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 2
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 3
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 4
+MOV [R16], 7
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 5
+MOV [R16], 8
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 6
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 7
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 8
+MOV [R16], -1
+MOV R16, 30032
+ADD R16, 10
+ADD R16, 9
+MOV [R16], -1
+MOV R0, 2
+_L7:
+MOV R16, 16
+GT R16, R0
+JZ R16, _L8
+MOV R16, 28672
+MOV R17, 16
+MUL R17, R0
+ADD R16, R17
+ADD R16, 4
+MOV [R16], 4
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L7
+_L8:
+MOV [29568], 0
+MOV [29552], 0
+MOV R16, 29560
+ADD R16, 0
+MOV [R16], 0
+MOV R16, 29560
+ADD R16, 2
+MOV [R16], 45
+MOV R16, 29560
+ADD R16, 3
+MOV [R16], 0
+MOV R16, 29560
+ADD R16, 24
+MOV [R16], 0
+MOV R16, 29560
+ADD R16, 25
+MOV [R16], 0
+MOV R16, 29560
+ADD R16, 26
+MOV [R16], 0
+MOV R0, 0
+_L9:
+MOV R16, 32
+GT R16, R0
+JZ R16, _L10
+MOV R16, 29056
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+MOV [R16], -1
+MOV R16, 29056
+MOV R17, R0
+MUL R17, 4
+ADD R16, R17
+ADD R16, 1
+MOV [R16], 0
+MOV R16, R0
+ADD R16, 1
+MOV R0, R16
+JMP _L9
+_L10:
+RET
+HALT
\ No newline at end of file
diff --git a/Stage22/Assgn2/timer.spl b/Stage22/Assgn2/timer.spl
new file mode 100644
index 0000000..779d05c
--- /dev/null
+++ b/Stage22/Assgn2/timer.spl
@@ -0,0 +1,36 @@
+// Store user SP to UPTR in process table -> 13 th word
+[PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 13] = SP;
+
+// Set SP to start of Kernel stack
+SP = [PROCESS_TABLE + [SYSTEM_STATUS_TABLE + 1] * 16 + 11] * 512 - 1;
+
+multipush(R2);
+
+alias prevMemUsage R2;
+prevMemUsage = SYSTEM_STATUS_TABLE + 25;
+if (128 - [SYSTEM_STATUS_TABLE + 2] > [prevMemUsage]) then 
+    [prevMemUsage] = 128 - [SYSTEM_STATUS_TABLE + 2];
+endif;
+
+multipop(R2);
+
+backup;
+
+// obtaining PID of the currently executing process
+alias currentPID R0;
+currentPID = [SYSTEM_STATUS_TABLE + 1];
+
+alias process_table_entry R1;
+process_table_entry = PROCESS_TABLE + currentPID * 16;
+
+[process_table_entry + 4] = READY;
+
+call MOD_5;
+
+restore;
+
+SP = [PROCESS_TABLE + 16 * [SYSTEM_STATUS_TABLE + 1] + 13];
+[PROCESS_TABLE + 16 * [SYSTEM_STATUS_TABLE + 1] + 12] = 0;
+[PROCESS_TABLE + 16 * [SYSTEM_STATUS_TABLE + 1] + 9] = 0;
+
+ireturn;
\ No newline at end of file
diff --git a/Stage22/Assgn2/timer.xsm b/Stage22/Assgn2/timer.xsm
new file mode 100644
index 0000000..ff4de10
--- /dev/null
+++ b/Stage22/Assgn2/timer.xsm
@@ -0,0 +1,87 @@
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 13
+MOV [R16], SP
+MOV R16, 28672
+MOV R17, 29560
+ADD R17, 1
+MOV R17, [R17]
+MUL R17, 16
+ADD R16, R17
+ADD R16, 11
+MOV R16, [R16]
+MUL R16, 512
+SUB R16, 1
+MOV SP, R16
+PUSH R2
+MOV R16, 29560
+ADD R16, 25
+MOV R2, R16
+MOV R16, 128
+MOV R17, 29560
+ADD R17, 2
+MOV R17, [R17]
+SUB R16, R17
+MOV R17, R2
+MOV R17, [R17]
+GT R16, R17
+JZ R16, _L1
+MOV R16, 128
+MOV R17, 29560
+ADD R17, 2
+MOV R17, [R17]
+SUB R16, R17
+MOV [R2], R16
+JMP _L2
+_L1:
+_L2:
+POP R2
+BACKUP
+MOV R16, 29560
+ADD R16, 1
+MOV R16, [R16]
+MOV R0, R16
+MOV R16, 28672
+MOV R17, R0
+MUL R17, 16
+ADD R16, R17
+MOV R1, R16
+MOV R16, R1
+ADD R16, 4
+MOV [R16], 1
+CALL 25600
+RESTORE
+MOV R16, 28672
+MOV R17, 16
+MOV R18, 29560
+ADD R18, 1
+MOV R18, [R18]
+MUL R17, R18
+ADD R16, R17
+ADD R16, 13
+MOV R16, [R16]
+MOV SP, R16
+MOV R16, 28672
+MOV R17, 16
+MOV R18, 29560
+ADD R18, 1
+MOV R18, [R18]
+MUL R17, R18
+ADD R16, R17
+ADD R16, 12
+MOV [R16], 0
+MOV R16, 28672
+MOV R17, 16
+MOV R18, 29560
+ADD R18, 1
+MOV R18, [R18]
+MUL R17, R18
+ADD R16, R17
+ADD R16, 9
+MOV [R16], 0
+IRET
+HALT
\ No newline at end of file
diff --git a/xfs-interface/stage22_2.sh b/xfs-interface/stage22_2.sh
new file mode 100644
index 0000000..e5909f6
--- /dev/null
+++ b/xfs-interface/stage22_2.sh
@@ -0,0 +1,32 @@
+load --os $HOME/myexpos/Stage13/os_startup.xsm
+load --init $HOME/myexpos/Stage21/Assgn1/shell2.xsm
+load --idle $HOME/myexpos/Stage14/idle.xsm
+load --int=10 $HOME/myexpos/Stage20/exit.xsm
+load --int=11 $HOME/myexpos/Stage21/int11.xsm
+load --int=13 $HOME/myexpos/Stage22/int13.xsm
+load --int=14 $HOME/myexpos/Stage22/int14.xsm
+load --int=15 $HOME/myexpos/Stage22/Assgn2/int15.xsm
+load --int=9 $HOME/myexpos/Stage19/int9.xsm
+load --int=8 $HOME/myexpos/Stage22/fork.xsm
+load --exhandler $HOME/myexpos/Stage21/exhandler.xsm
+load --int=7 $HOME/myexpos/Stage15/int7.xsm
+load --int=6 $HOME/myexpos/Stage16/int6.xsm
+load --int=disk $HOME/myexpos/Stage18/int2.xsm
+load --int=console $HOME/myexpos/Stage16/console_int.xsm
+load --module 5 $HOME/myexpos/Stage22/Assgn2/mod5.xsm
+load --module 7 $HOME/myexpos/Stage22/Assgn2/mod7.xsm
+load --module 0 $HOME/myexpos/Stage22/Assgn2/mod0.xsm
+load --module 1 $HOME/myexpos/Stage22/mod1.xsm
+load --module 2 $HOME/myexpos/Stage19/module_2.xsm
+load --module 4 $HOME/myexpos/Stage18/module_4.xsm
+load --int=timer $HOME/myexpos/Stage22/Assgn2/timer.xsm
+rm test4.xsm
+load --exec $HOME/myexpos/Stage22/Assgn1/test4.xsm
+rm parent.xsm
+load --exec $HOME/myexpos/Stage22/Assgn2/parent.xsm
+rm child.xsm
+load --exec $HOME/myexpos/Stage22/Assgn2/child.xsm
+rm con.xsm
+load --exec $HOME/myexpos/Stage22/Assgn3/con.xsm
+rm seq.xsm
+load --exec $HOME/myexpos/Stage22/Assgn3/seq.xsm
\ No newline at end of file