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Machine code routine neededHello! Please i'm looking for a short routine that can write the same value in a range of continous memory locations. For example, to write 255 val…
... /> ld (savesp+1),sp ; save stack pointer
...
savesp: ld sp ... ,0 ; restore stack pointer
[/code][/quote]
That bombing map on Deathwake..Did it make a difference? If you target the enemy airfields, you still seem to get the same number of aircraft attacking. And targetting the enemy po…
... incorrect, every play shifts the stack pointer.
Solution: POKE 34883 ...[Asm] Is this nested loop faster than LDIR or a bunch of unrolled LDI's?Hi all. I'm learning Z80 asm on Speccy 48K, and to start with I decided to write my own "CLS" routine (without relying on ROM calls or LDIR) as a lea…
... was going on at the stack+1 label, it appears to ... variable to store the original stack pointer - injecting directly into the instruction ...Raster effects - quick questionHi Guys Just a quick question regards what the ULA is doing as its drawing each scan line. Assuming the beam has finished drawing the border, am I…
What to write / programme?I've been trying to get back some motivation to write something in machine code for the Spectrum. I don't feel I am organised enough to write somethi…
... , I prefer to redirect the stack temporarily to where the tile ... sure that you store the stack pointer at the beginning of your ... tile we would redirect the stack pointer to HL (which is pointing ...What to write / programme?I've been trying to get back some motivation to write something in machine code for the Spectrum. I don't feel I am organised enough to write somethi…
... , I prefer to redirect the stack temporarily to where the tile ... sure that you store the stack pointer at the beginning of your ... tile we would redirect the stack pointer to HL (which is pointing ...What to write / programme?I've been trying to get back some motivation to write something in machine code for the Spectrum. I don't feel I am organised enough to write somethi…
... it later. You have a Stack pointer (SP) which is a ... the memory address at the Stack Pointer.
But POPPING ... br />
So if the stack pointer is pointing to the first ... /> Each POP BC advances the stack pointer 2 bytes through your tile ...Zynaps scrolling - anyone ever reverse enginnered this?Zynaps has IMO some impressive scrolling - it utilises 18 character rows of the display file, so quite a large active play area, and scrolls 2 pixels…
... at some points using the stack pointer to point to the data ...Is it possible to make the Z80 execute a bizarre instruction?What happens when it gets an unrecognised instruction OP Code, I mean something following a #ED that isn't one of the undocumented instructions eithe…
... going to be moving the stack pointer or using interrupt modes. That ...Is it possible to make the Z80 execute a bizarre instruction?What happens when it gets an unrecognised instruction OP Code, I mean something following a #ED that isn't one of the undocumented instructions eithe…
... going to be moving the stack pointer or using interrupt modes. That ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... that. You could stash the stack pointer if you want to return ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... that. You could stash the stack pointer if you want to return ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... that. You could stash the stack pointer if you want to return ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... /> push hl ; push data pointer
cp WALL
... to play with the stack pointer, and self modifying code ... br /> ld (.stack+1), sp ;store current stack pointer
ld ... hl, 0 ;this value will be stored on stack ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... /> ld (.stack+1), sp ;store current stack pointer
ld ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... ret
; de pointer to 8 bytes graphic data ... of sprite16x16a
; de = pointer to 32 bytes graphic data ... ret
; de = pointer to 32 bytes graphic data ... br /> ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... of sprite16x16a
; de = pointer to 32 bytes graphic data ... a
; increment data pointer twice to double stride
ret
; de = pointer to 32 bytes graphic data ... br /> ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... ret
; de pointer to 8 bytes graphic data ... of sprite16x16a
; de = pointer to 32 bytes graphic data ... ret
; de = pointer to 32 bytes graphic data ... br /> ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... (self modifying code, changing the stack pointer).
You can use ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... interrupt
ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... again) and mess with the stack without setting it back to ... to go off when the stack pointer was being messed with everything ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... interrupt
ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... br /> ld (.stack+1), sp ;store current stack pointer
ld ... push hl ;store hl on stack
push hl ; ... push hl ;store hl on stack
push hl ; ... by ld (.stack+1), sp ;store current stack pointerHow to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... interrupt
ld (.stack+1), sp ;store current stack pointer
ld sp ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... /> ld (.stack+1), sp ;store current stack pointer
ld ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... ret
; de pointer to 8 bytes graphic data ... of sprite16x16a
; de = pointer to 32 bytes graphic data ... ret
; de = pointer to 32 bytes graphic data ... br /> ld (.stack+1), sp ;store current stack pointer
ld sp ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... /> ld (.stack+1), sp ;store current stack pointer
ld ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... it doesn't increment the stack pointer.
(SP) L; (SP ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... /> ld (.stack+1), sp ;store current stack pointer
ld ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ... hl ;store hl on stack
push hl ; ...SCF/CCF flags - new discoveryI can't believe that no one is interested in discussing the additional, previously undocumented internal state of the Z80 CPU I have discovered recen…
... it doesn't increment the stack pointer.
(SP) L; (SP ... would end up with the stack pointer value or something. I'll ...
