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(Collected) Darkhog's noob question about z80 assemblySince when I'm learning new language or library, I tend to ask lots of stupid (for any advanced person) questions and I don't want it to have mess up…
[quote="Darkhog;52514"]
- Regular IF z80 equivalent. e.g. If A -
Function with push and popIm trying to see if I understand push and pop when it comes to using to pass parameters to functions: [code] LD HL,16384 LD A,5 Push AF Ld A…
... br /> push ix
ld ix,0
add ix,sp
; ix+4 = parameter '7'
; ix ... ; return value by register DEHL
pop ix
ret
register but in a compiler environment ... -
Function with push and popIm trying to see if I understand push and pop when it comes to using to pass parameters to functions: [code] LD HL,16384 LD A,5 Push AF Ld A…
... is it standard to use IX and IY?
IX or IY are used because ... Gameboy Z80 there were no IX or IY registers, so ... only slightly slower than using IX or IY!)
... to it, in the index register (IReg) you choose. It ... -
Function with push and popIm trying to see if I understand push and pop when it comes to using to pass parameters to functions: [code] LD HL,16384 LD A,5 Push AF Ld A…
... , and -in combination with A register- even some arithmetic.
IX+n or IY+n is ... -
Function with push and popIm trying to see if I understand push and pop when it comes to using to pass parameters to functions: [code] LD HL,16384 LD A,5 Push AF Ld A…
... directly without using an extra register. Having said that, and ... buffer at address SP1V_PIXELBUFFER. ix points to the sprite ... block pointer
196 ; ix + 03/04 investigate block pointer ...
197 ; ix + 01/02 new block pointer ... -
r-type in development for the sam coupehttp://cookingcircle.co.uk/ we need z80 coders graphics artists and audio this is the amstrad cpc 6128 version: https://www.youtube.com/watc…
Help needed with MIA software with custom (?) loaderHi, I've got into my hands recently a bunch of Polish educational software which are unknown MIA on WOS. I believe they are protected with some…
... PUSH IX ; Save IX (source address)
0xEB58 EXX ; Swap to altenate register ... to main register file
0xEB77 POP IX ; Restore new IX (source address ...IXL and IXHI don't know much about undocumented instructions but I get the impression that [b]LD A,IXH[/b] or [b]LD A,IXL[/b] (B, C, D, E also fine, HL not) are…
... of these instructions that use IX or IY, IXH, IXl, IYH ... to the address in the register at the time of use ...Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... it (in)directly using the ix (or iy) register.Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... halves of IX/IY registers, as well as the shadow register set ... regular ones.
The shadow register set is very useful when ... and offload that onto index register halves/shadow regs/the memory ... can't find a spare register for one (although, depending on ...Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... needed. Don't waste a register pair if all possible values ... fit in an 8-bit register.
A (really) simple ... AF,AF' / EXX
* Use IX/IY if possible
* PUSH ... stack manipulation (IX/IY+... operations, use SP as work register etc)
Running out of fingers in AssemblyDear all, Still trying to learn Assembly and have put a few routines together. However, as my routines become a little more involved I find myself…
... into the block. The register pressure is then relieved ... br /> push de
pop ix
; use generic ... br /> ; bc = radix
; ix = char *buf
; ... to string
; ix = char *buf
; stack ...Optimized (in size) Z80 simulatorI am evaluating Z80 simulators to try to create a tool to analyse z80 programs. I'd like to start with a simple register coverage tool and t-state cy…
... variable)
5) JP (IX) f.e. Where does it ... your program uses pre-set IX value (for example, from ... know that LD IX,100 writes to IX. You can follow ... also know that if IX is changed somewhere in between ... A. If you have register coverate you should know when ...I'm writing an Operating SystemOkay this might seem like a bait thread, but I am legitamately interested in figuring out how to write a multi-process system for the ZX Spectrum (no…
... the calculation because the register assignments have made it ... [19] 343 ld a,-4 (ix)
010C C6r00 [ 7] ... FD [19] 348 ld -3 (ix),a
[/code]
... in the stack so relative ix addressing is actually best. ...Interrupt routineI have been trying to create an interrupt routine for playing AY music in the background but cant seem to get anything working. I have a music rou…
... interrupt routine
LD IX,&FFF0 ; Where to ... this code
LD (IX+04h),&C3 ; Z80 ... LD I,A ; Set I register to this
IM 2 ... /> PUSH HL
PUSH IX
EXX
EX ... EX AF,AF'
POP IX
POP HL
...Look whats possible in 924 bytesSo, finally after over a year of development and nearly 25 years since I first designed the graphics, I've actually made it to the point where this i…
... hl
ix_store:
ld ix,0fc00h
ld a,40h ... bit 7 of the data register lo-byte to determine if ... counter
ld a,(ix+00h) ;A=data byte
Look whats possible in 924 bytesSo, finally after over a year of development and nearly 25 years since I first designed the graphics, I've actually made it to the point where this i…
... /> ld a,00h
ld ix,0fc00h
rra
jr ... bit 7 of the data register lo-byte to determine if ...
ld a,(ix+00h) ;A=data byte
Look whats possible in 924 bytesSo, finally after over a year of development and nearly 25 years since I first designed the graphics, I've actually made it to the point where this i…
... 7 of the data register lo-byte to determine ... />
ld a,(ix+00h) ;A=data byte
register lo-byte to determine ... counter B first. The register is checked, and if ... the stream using address IX and bit number D ...Look whats possible in 924 bytesSo, finally after over a year of development and nearly 25 years since I first designed the graphics, I've actually made it to the point where this i…
... counter
ld a,(ix+00h) ;A=data byte
IX address register if needed.The HL Register Pair Naming. An Observation.This isn’t really a question or a tip. Just an observation about the naming convention of the registers in the Z80 CPU. It seems that every register …
... to use I for Interrupt register!"
"What about A ... ."
"But they are register pairs!"
"OK, let ... pairs, let's call them IX and IY."
"But ... same high value, taken from register I."
"Oh sh ...The HL Register Pair Naming. An Observation.This isn’t really a question or a tip. Just an observation about the naming convention of the registers in the Z80 CPU. It seems that every register …
... pairs, let's call them IX and IY."
"But ... same high value, taken from register I."
"Oh sh ... , I originally thought that with IX and IY, the value in ...z80 Helper?When you are programming with z80 do you get 'lost' you are in the middle of making a routine and you can't remember which registers are holding val…
... outward from there. Optimal register assignment and stack usage will ... directly address with "ld a,(ix+n)" type instructions. Many ... a human, using an IX-indexed stack to access temporaries ... Slightly more common is using IX-indexed data structures where code ...The point of IX+1 IX+2 ?the numbers that you can add-on to IX and IY seem hardcoded, so I dont see the use of that feature? any examples of the use of IX and IY plus number…
... in z80 code using IX that can access object ... data with (ix+n) addressing and can ... a call to jp(ix) with IX pointing at a jp ... name in the "A" register. Inheritance is done by appending ... This simple functionality around IX almost makes it seem ...The point of IX+1 IX+2 ?the numbers that you can add-on to IX and IY seem hardcoded, so I dont see the use of that feature? any examples of the use of IX and IY plus number…
... in z80 code using IX that can access object ... data with (ix+n) addressing and can ... a call to jp(ix) with IX pointing at a jp ... name in the "A" register. Inheritance is done by appending ... This simple functionality around IX almost makes it seem ...The point of IX+1 IX+2 ?the numbers that you can add-on to IX and IY seem hardcoded, so I dont see the use of that feature? any examples of the use of IX and IY plus number…
... /> push de
pop ix ; ix = pointer to player
... l_jpix:
jp (ix)
[/code]
register. In this case " ... handle_character_add_hp:
; ix = pointer to a character
What is the maximum fps the spectrum can achieve?I have been doing some reading and from what I understand the Spectrum outputs a PAL signal, but that means it will display @50fps or @25fps? If t…
... tiles can be held in register pairs ready for PUSHing.
IX and IY pairs within the ... very complicated to track the register swaps back and forth on ...ZX Spectrum Z80 Development Environment on WindowsHi Folks, Just wondering what the recommendation is for a ZX Spectrum Z80 Development environment on Windows? Getting fed up with hand coding Z80…
... you could somehow use another register in there anyway), or EXA ... especially stuff like 'LD HL,IX' realized as 'PUSH HL: POP ... IX' (an actual example from Sjasm+) ... syntax like 'LD A,+0(IX)'. This is exactly the sort ...ZX Spectrum Z80 Development Environment on WindowsHi Folks, Just wondering what the recommendation is for a ZX Spectrum Z80 Development environment on Windows? Getting fed up with hand coding Z80…
... you could somehow use another register in there anyway), or ... especially stuff like 'LD HL,IX' realized as 'PUSH HL: ... br />
"LD HL,IX" as soon as you remember ... like 'LD A,+0(IX)'. This is exactly the ... />
Yes, the "n (ix)" syntax is not right, a ...ZX Spectrum Z80 Development Environment on WindowsHi Folks, Just wondering what the recommendation is for a ZX Spectrum Z80 Development environment on Windows? Getting fed up with hand coding Z80…
... you could somehow use another register in there anyway), or EXA ... bring up the 'LD HL,IX' example as bad because it ...A Neat Redefine Keys RoutinePreviously, I’ve only shared this routine with a couple of people via PM, but I’ve now decided to make it public. I optimized it for size, so it uses…
... otherwise, use a 16-bit register
;pair, such as ... first keycode
ld ix,controls_i ;location of the ... .002)
push ix ;preserve IX, as the BEEP routine destroys ... ROM beeper routine
pop ix ;restore IX
ex ...
