Pas2C64

[paul_nicholls]

Ok, for the time being, I am going to support these types in my compiler - integer (signed 16-bit), single (32-bit), and string (up to 255 characters max)...

I can now read in Pascal syntax constants and variables using these standard types, and store them in generated assembly code.

I feel I am very close to actually doing some assignment statements, and probably some math too in the compiler

I have also found out how to detect key presses, so I will have routines for this too; WaitForAnyKey and WaitForKey(some key code), and probably even IsKeyPressed(some key code).

I think I know how I will do inputting of strings from the keyboard (not sure about numbers though yet)...

cheers,
Paul

[paul_nicholls]

After I found a very simple c64 interrupt routine here:

http://xabreman.wordpress.com/2011/0...rrupt-example/

I thought that I can do this too, so by adding some new routines into the Pascal language & their support framework (parsing + code generation), I can now actually do this very same interrupt routine using compiled Pascal routines:

program Test;

procedure irqtest; interrupt;
begin
  IncMemB($d020);
  StdIRQ;
end;

procedure Init;
begin
  SetInterrupt(irqtest);
end;

begin
  Init;
end.

which produces this:

    :BasicUpstart2(main) // 10 sys <start address>
    
    .import source "rtl\Macros_RTL.asm"
    .import source "rtl\Consts_RTL.asm"
    
int_irqtest:
    inc $d020
    jmp STDIRQ
    rti
proc_init:
    sei       // disable interrupts
    
    // set a custom interrupt routine address to interrupt vector
    
    lda #<int_irqtest       // low byte of irqtest start addr
    ldx #>int_irqtest       // high byte of irqtest start addr
    sta IRQVECLO
    stx IRQVECHI
    
    cli                 // clear interrupt disable bit
    rts
main:
    jsr proc_init
    rts

and when run in the c64 VICE emulator, it hooks the interrupt routine into the interrupt vector and merrily runs in the background incrementing the background colour!

Now this is progress!! haha

cheers,
Paul