Improve UI

README.md

@@ -22,6 +22,10 @@ your machine. Under Linux the makefile should run without changes as long as ACM
 
 ![](/result.png?raw=true "Example picture in hires mode")
 
+# Using the program
+
+When you start the program you can select whether you want to start with the current 
+
 # Zooming into the Mandelbrot set
 
 The calculation can be interrupted at any time by pressing a key and resumed by again by pressing `RETURN`. 
@@ -38,7 +42,7 @@ select the new section:
 The cursor keys can be used to move a rectangular frame of reversed pixels over the visualization. The frame
 represents the currently selected new section. `F1` and  `F3` can be used to change the size of that frame. 
 Pressing return starts the calculation of the selected subsection. If the  caclulation has finished you can 
-also select a new subsection  after pressing `F5`. Pressing any other key ends the program.
+also select a new subsection after pressing `F5`. Pressing any other key ends the program.
 
 Zooming in essence halves the stepping width in X and Y direction and increases the so called zoom level by one. 
 As this software uses fixed point arithmetic this results in a loss of accuracy which at a certain point can 
@@ -51,9 +55,7 @@ visibly. Here an example of this effect at zoom level 12 and iteration depth 64.
 
 # Limitations at the moment
 
-- No possibility to save the caclulated picture. As a primitive workaround all the parameters needed to recreate
-the last picture are printed to the screen when the program shuts down.
-- No possibilty to view a saved picture
+- Loading and saving pictures only work with a mounted SD-card image. I am at the moment not sure if I can do anything about that.
 - As I do not have access to real hardware and therefore have to use the X16 emulator it is not 100% sure that the program
 performs in the same way on a real machine
 - I have not yet tested whether my fixed point math routines are actually faster than the floating point routines

disk_io.a

@@ -67,7 +67,7 @@ readErrorChannel
 
     ; open 15,DEVICE_NUM,15
     +openChannelNoFileName 15, DEVICE_NUM, 15
-    bcs .checkError                   ; open failed
+    bcs .handleOpenError              ; open failed
 
     ldx #15
     jsr CHKIN                         ; use file 15 as input
@@ -89,15 +89,15 @@ readErrorChannel
 .close 
     lda #15                           
     jsr CLOSE                         ; close file 15
-.endWithoutClose                       
+;.endWithoutClose                       
     jsr CLRCHN                        ; restore default input and output channels
 
     rts
-.checkError
+.handleOpenError
     ; room for additional error handling
     lda #DISK_IO_ERR
     sta DISK_ERROR
-    jmp .endWithoutClose              
+    jmp .close                        ; Even if open failed we have to close the channel              
 
 
 ; --------------------------------------------------

main.a

@@ -448,6 +448,12 @@ selectIterationDepth
 !tx "LOADING ..."
 !byte 13
 
+.TXT_SAVING
+!byte 11
+!tx "SAVING ..."
+!byte 13
+
+
 ALLOWED_FILE_CHARS
 !byte 37
 !tx "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789."
@@ -467,6 +473,7 @@ savePicture
     pla
     cmp #0
     beq .noSave                                          ; do nothing if user entered an empty string
+    +printStr .TXT_SAVING    
     jsr saveHiresDataToDisk                              ; save data from banked RAM to disk
     rts
 
@@ -493,6 +500,7 @@ loadPicture
     rts
 
 .noLoad
+    lda #DISK_IO_ERR
     rts
 
 .TXT_SELECT
@@ -526,6 +534,9 @@ progStart
     jsr loadPicture
     cmp #DISK_IO_OK
     beq .doShowAfterLoad               ; do nothing if load failed 
+    jsr readAndEvalErrorChannel        ; read error channel
+    +printStr ERR_BYTE_COUNTER         ; print error message
+    jsr printCRLF    
     rts
 .doShowAfterLoad      
     jsr bitMapOn                       ; This also clears Video RAM
@@ -574,6 +585,9 @@ progStart
     cmp #KEY_DO_SAVE
     bne .infoOnly
     jsr savePicture                    ; save picture if user pressed F7. No error check. The routine generates error messages
+    jsr readAndEvalErrorChannel        ; read error channel
+    +printStr ERR_BYTE_COUNTER         ; print error message
+    jsr printCRLF
 .infoOnly
     jsr .printLastValues               ; print info about values used for calculation
 .endMandel