Add origins for all CHIPOS routines

Should not change assembler output, but makes locations explicit and consistent with CHIPOS manual. Will help with future modifications.
tobiasvl · Apr 22, 2020 · dea7bd7 · dea7bd7
1 parent f904f60
commit dea7bd7
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Showing 2 changed files with 67 additions and 1 deletion.
diff --git a/CHIPOS68.asm b/CHIPOS68.asm
@@ -140,8 +140,14 @@ EXCALL: LDAB    PIR         ; GET INSTR REG
         CMPA    #$EE
         BEQ     RETDO
         RTS                 ; NOP, FETCH
+;
+        ORG     $C079
+;
 ERASE:  CLRA                ; WRITE ZEROS TO SCREEN
         LDX     #DISBUF     ; POINT TO DISPLAY BUFF
+;
+        ORG     $C07D
+;
 FILL:   STAA    0,X         ; FILL SCREEN WITH ACC-A
         INX
         CPX     #ENDBUF     ; DONE?
@@ -250,6 +256,8 @@ PUTVX:  LDX     VXLOC       ; REPLACE VX
         RTS
 ;
 ; RANDOM BYTE GENERATOR
+;
+        ORG     $C132
 ;
 RANDOM: LDAA    #$C0        ; HIGH-ORDER BYTE OF RNDX =
         STAA    RNDX        ; =MSB OF CHIP8 START ADRS
@@ -313,6 +321,8 @@ LETIV:  CLRB                ; 16-BIT ADD VX TO I
 ;
 ; COPY COMPRESSED DIGIT PATTERN (FROM TABLE)
 ; TO  5-BYTE ARRAY (DDPAT), & SET I FOR 'SHOW',
+;
+        ORG     $C193
 ;
 LETDSP: LDX     #HEXTAB-2   ; POINT TO HEX DIGIT PATTERNS ,
         ANDA    #$0F        ; ISOLATE LS DIGIT
@@ -358,6 +368,9 @@ HEXTAB: FDB     $F6DF       ; 0
         FDB     $934F       ; F
 ;
 LETDEQ: LDX     I           ; GET MI POINTER
+;
+        ORG     $C1E0
+;
         LDAB    #100        ; N=100
         BSR     DECI        ; CALC 100'S DIGIT
         LDAB    #10         ; N=10
@@ -399,7 +412,13 @@ MOVX1:  PULA                ; GET NEXT V
 ;
 SHOW:   LDAB    PIR+1       ; GET N (OPCODE LSB)
         CLR     VF          ; CLEAR OVERLAP FLAG
+;
+        ORG     $C224
+;
 SHOWI:  LDX     I           ; POINT TO PATTERN BYTES
+;
+        ORG     $C226
+;
 SHOWX:  LDAA    #$01        ; SET DISPLAY ADRS MSB =
         STAA    BLOC        ; = DISBUF HIGH-ORDER BYTE.
         ANDB    #$0F        ; COMPUTE NO. OF BYTES (N)
@@ -444,6 +463,8 @@ SHOWUP: TAB                 ; UPDATE DISPLAY BYTE
 SHOWR:  RTS
 ;
 ; COMPUTE ADRS OF DISPLAY BYTE AT COORDS(B, VY):
+;
+        ORG     $C275
 ;
 DISLOC: LDAA    VY          ; FETCH Y COORD
         ANDA    #$1F        ; MASK TO 5 BITS FOR WRAP-ROUN
@@ -460,6 +481,8 @@ DISLOC: LDAA    VY          ; FETCH Y COORD
         RTS
 ;
 ; KEYPAD ROUTINES
+;
+        ORG     $C287
 ;
 PAINZ:  LDAB    #$F0        ; INITIALIZE PORT
 PAINV:  LDX     #PIAA       ; (ENTRY PT FOR INV. DDR)
@@ -471,6 +494,8 @@ PAINV:  LDX     #PIAA       ; (ENTRY PT FOR INV. DDR)
         RTS
 ;
 ; KEYPAD INPUT SERVICE ROUTINE
+;
+        ORG     $C297
 ;
 KEYINP: BSR     PAINZ       ; RESET KEYPAD PORT
         CLR     BADRED      ; RESET BAD-READ FLAG
@@ -501,6 +526,8 @@ KBILD1: INCA                ; (A=RESULT)
         RTS
 ;
 ; GETKEY WAIT FOR KEYDOWN, THEN INPUTS
+;
+        ORG     $C2C4
 ;
 GETKEY: STX     XTEMP       ; SAVE X FOR CALLING ROUTINE
 GETK1:  BSR     PAINZ       ; RESET PORT, CLEAR FLAGS
@@ -518,10 +545,15 @@ HEXK1:  BSR     BLEEP       ; O.K. ACKNOWLEDGE
         RTS                 ; RETURN (WITH A<O FOR FN KEY)
 ;
 ; TONE GENERATING ROUTINES
+;
+        ORG     $C2DF
 ;
 BLEEP:  LDAB    #4
 BTONE:  STAB    TONE        ; SET DURATION (RTC CYCLES)
         LDAB    #$41        ; TURN AUDIO ON
+;
+        ORG     $C2E5
+;
         STAB    PIAB
 BTON1:  TST     TONE        ; WAIT FOR RTC TIME-OUT
         BNE     BTON1
@@ -530,8 +562,13 @@ BTON1:  TST     TONE        ; WAIT FOR RTC TIME-OUT
         RTS
 ;
 ; SOFTWARE DELAY ROUTINE FOR SERIAL I/O:
+;
+        ORG     $C2F3
 ;
 DEL333: BSR     DEL167      ; DELAY FOR 3.33 MILLISEC
+;
+        ORG     $C2F5
+;
 DEL167: PSHB
         LDAB    #200        ; DELAY FOR 1.67 MILLISEC
 DEL:    DECB
@@ -543,6 +580,8 @@ DEL:    DECB
 ; TAPE INPUT/OUTPUT ROUTINES
 ; INITIALIZE TAPE, TONE, RTC, & DMA
 ; A=$3F FOR DISPLAY/DMA ON; A=$37 FOR OFF:
+;
+        ORG     $C2FE
 ;
 PBINZ:  LDX     #PIAB
         LDAB    #$3B        ; SELECT DDR (DMA ON)
@@ -555,6 +594,8 @@ PBINZ:  LDX     #PIAB
         RTS
 ;
 ; INPUT ONE BYTE FROM TAPE PORT
+;
+        ORG     $C310
 ;
 INBYT:  BSR     XCHG        ; EXCHANGE X FOR PIA ADRS
 IN1:    LDAA    0,X
@@ -573,6 +614,8 @@ XCHG:   STX     XTEMP       ; SAVE   X-REG
         RTS
 ;
 ; OUTPUT ONE BYTE TO TAPE PORT
+;
+        ORG     $C32B
 ;
 OUTBYT: BSR     XCHG
         PSHA
@@ -611,6 +654,8 @@ LOAD1:  BSR     INBYT
 ;      (BRA START)
 ;
 ; MONITOR ENTRY POINT
+;
+        ORG     $C360
 ;
 START:  LDS     #STOP       ; RESET SP TO TOP
         LDX     #RTC        ; SETUP IRQ VECTOR FOR RTC
@@ -637,6 +682,9 @@ INADRS: BSR     BYT1        ; BUILD ADRS MS BYTE
         STAA    ADRS+1
         BSR     SHOADR      ; DISPLAY RESULTANT ADRS
         BRA     COMAND
+;
+        ORG     $C390
+;
 BYTIN:  BSR     GETKEE      ; INPUT 2 HEX DIGITS
 BYT1:   ASLA                ; LEFT JUSTIFY FIRST DIGIT
         ASLA
@@ -671,20 +719,35 @@ SHOADR: LDAA    #$10        ; SET CURSOR HOME POSITION
         BSR     SHODAT
         BSR     CURSR       ; MOVE CURSOR RIGHT
         RTS
+;
+        ORG     $C3C8
+;
 SHODAT: LDAA    0,X         ; FETCH DATA @ X
+;
+        ORG     $C3CA
+;
 SHOBYT  PSHA
         LSRA                ; ISOLATE MS DIGIT
         LSRA
         LSRA
         LSRA
         BSR     DIGOUT      ; SHOW ONE DIGIT
         PULA
+;
+        ORG     $C3D2
+;
 DIGOUT: STX     XTEMP       ; SAVE X
         JSR     LETDSP      ; POINT TO DIGIT PATTERN
         LDAB    #5          ; SHOW 5-BYTE PATTERN
         JSR     SHOWI
+;
+        ORG     $C3DC
+;
 CURSR:  LDAA    #4          ; SHIFT CURSOR RIGHT 4 DOTS
         ADDA    VX
+;
+        ORG     $C3E0
+;
 CURS1:  STAA    VX          ; SET X COORD
         LDAA    #$1A        ; SET Y COORD
         STAA    VY
@@ -699,9 +762,10 @@ RTC:    DEC     TIMER
         RTI
 IRQ:    LDX     IRQV        ; INDIRECT JUMP VIA IRQV
         JMP     0,X
-        FCB     0
 ;
 ; RESTART AND INTERRUPT TRAPS
+;
+        ORG     $C3F8
 ;
         FDB     IRQ         ; (ALLOWS USER-WRITTEN ISR)
         FDB     $0080       ; SWI ROUIINE AT $0080 (OPTION)

diff --git a/README.md b/README.md
@@ -18,3 +18,5 @@ p2bin -l 0 CHIPOS68.p
 ```
 
 The CHIPOS code in this repo is also available for download on [Michael J. Bauer's DREAM 6800 website](http://www.mjbauer.biz/DREAM6800.htm). Michael has stated to me in private correspondence that the code is in the public domain.
+
+This version contains several origins. These are not needed for assembly (besides the last one that makes sure the interrupt vectors are located at the highest addresses), but they also serve to denote sections of the code that programs will expect to stay put, should you wish to edit it while still staying CHIPOS-compatible. These addresses were all found in the document "CHIPOS SUBROUTINES (& Calling Sequences)" from Michael J. Bauer's website.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -18,3 +18,5 @@ p2bin -l 0 CHIPOS68.p
		```

		The CHIPOS code in this repo is also available for download on [Michael J. Bauer's DREAM 6800 website](http://www.mjbauer.biz/DREAM6800.htm). Michael has stated to me in private correspondence that the code is in the public domain.

		This version contains several origins. These are not needed for assembly (besides the last one that makes sure the interrupt vectors are located at the highest addresses), but they also serve to denote sections of the code that programs will expect to stay put, should you wish to edit it while still staying CHIPOS-compatible. These addresses were all found in the document "CHIPOS SUBROUTINES (& Calling Sequences)" from Michael J. Bauer's website.