Sinclair ZX80 / ZX81 / Z88 Forums

The program with the small loader never gets to the LD (HL),C since the ROM takes off the RET in IN-BYTE when tape is waiting for a signal. The IN-BYTE must be customized too for a loader. ;; IN-BYTE L034C: LD C,$01 ; prepare an eight counter 00000001. ;; NEXT-BIT L034E: LD B,$00 ; set counter to 25...

Ok, my findings sofar:

On EightyOne you can only get it a bit working when using WAV-loader.
With .P and .TZX EightyOne uses a different loading trick.

Even with WAV I don't return to the loader I defined (yet).

D was set to same highbyte as RET-address and test in ROM sees that as a stop in loading.
After the LDIR I did a INC D and now tape stays in loader.

Next step is actual loading.

I put a startaddress on the stack, therefore the stack comes at 43fe. Then the loader will overwrite first byte with RET

I was thinking of this loader: START: call SET_FAST ; load operations to be managed in FAST mode ld sp, #4400-2 ; / ld hl, 0x4000 ; start loading data at 4000h ld hl, LOAD_PROG_BEG ; relocate loader to end of memory ld de, TARGET_LOAD ; / push de ; / ld bc, LOAD_PROG_END - LOAD_PROG_BEG ; / ldir ; ...

So I have the loader starting, but how do I built my datablock to load?

I am using EightyOne to test the program.

Who can help with a working exemple?

The block to load is then 1010 bytes when my idea is working where at the end the stack will get a few more bytes.

I was thinking of this loader: START: call SET_FAST ; load operations to be managed in FAST mode ld sp, #4400-2 ; / ld hl, 0x4000 ; start loading data at 4000h ld hl, LOAD_PROG_BEG ; relocate loader to end of memory ld de, TARGET_LOAD ; / push de ; / ld bc, LOAD_PROG_END - LOAD_PROG_BEG ; / ldir ; _...

The forum was slow this weekend.

The layout altered again and Russia is added again.

Game is ready but now only for the tributers.

The loader routine is just 17 bytes ("_BEG" to "_END"), and it is relocated to the end of the memory at the program start. Everything else is rewritten as all the rest of the memory during the load process. And become even 16 bytes because the loader stop when it starts overwriting itself (for now ...