Sinclair ZX80 / ZX81 Forums

The TASM ZX81's kit... (EO & VB81xur) TASM_ZX81.zip EO: TASM compil a 'P' file... (you had to reload the P file to refresh the file...) VB81 XuR: Create and load the BLANK text file (one REM), select the REM to assign the memory room, in the disassembler window. Load (refresh) the binary in the rem ...

:mrgreen: LD A,$00 DEC HL CP H Lb40A4: LD BC,0000 CALL CURSEUR ; Set the basic cursor to x,y (0,0) LD HL,$03BF ; HL=counter+$00FF=$02C0+$00FF Lb40A7: LD A,161 ; '5' to display RST 10H ; Display= A reg. LD A,$00 ; set A DEC HL ; ... CP H ; compare H<>A... if HL=$00FF set AF register z=1 to exit the l...

:D Earlier you mentioned that DEC BC affected the flags Z register. According to my book (Zaks) the DEC rr call doesn't affect any registers. True. DEC HL RET N Won't work. The F flag (AF register) isn't updated like a DEC H ! Hence the reason why it has to be tested using the accumulator. You use a...

Hi rune, The main way to print a character on the zx81, is to feed the D_file (video memory), using the LD (address) function (POKE). The RST10 (Call $0010) pass the A register to the ROM display routine. LDIR able to copy a part of memory from HL to DE, with the BC lenght. LD HL,$4100 ; From LD DE,...

Yes, The first RET Z don't work.
I tryed using the A register with a "OR A" to clean the F register, CCF for the carry...
But, the ROM seem to add a new jump to the PC accumulator...
Two RET seem working !

5 examples to fill a screen. #include ZX81.sym #define ORG .org ; TASM cross-assembler definitions #define equ .equ ;----------------------------------- ;------- Rom and Ram Symbols ------- RAM_D_FILE equ $400C ; D_file address. EXTERR equ $005B ; Basic Break function ! Ignore line instructions. CUR...

Use the RST10 function, to avoid to destroyed the n/l character...
@rune : (22 lines x 32 )+23 (new/line=$76)

Yes, a funny Game !

The numeric display routine is good, and point to the line address in the machine code routine (retrieved in the dedicated ROM routine)!

1 LET R=PI/PI 5 LET L=NOT R 10 LET Q=NOT PI/PI 20 PRINT ,,("YOU ARE IN A CAVE." AND R=1);(" IN THE CAVE IS A LAMP" AND NOT L AND R=1);(" LAMP TAKEN, YOU CAN NOW SEE FURTHER." AND L=1 AND R=1);(" THE CAVE IS NOW BRIGHT AND YOU CAN SEE THE TREASURE I THE DISTANCE" AND L=1 AND R=1);("TRAP SPRUNG. YOU ...

sorry for that, I might fix it, I might not, depends

Sorry for that too, we might help you, we might not, depends