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need help with speed optimization. this procedure draws a sprite with mask from memory onto the screen with x-coordinate in pixels. it doesn't shift sprites in realtime, it just uses …
... H or L registers with the normal prefixes for IX and IY ... low bytes of the index registers. This doesn't work for ... -
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... br />
MainLoop:
; Store Registers, as we dont know where ...
; Recall
POP IX
POP HL
POP ... LD A,(IX+3)
SUB (ix+7)
ld (IX+3),A ... -
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... br />
MainLoop:
; Store Registers, as we dont know where ...
; Recall
POP IX
POP HL
POP ... LD A,(IX+3)
SUB (ix+7)
ld (IX+3),A ... -
I would like to write emulatorHi guys, I'm new to this forum but I realise that you must get loads of posts from people asking "how do I write an emulator" so I'll try and be spe…
... register (i.e. PC, SP, IX, IY) when we use the ... />
Yes, all 16 bit registers (including PC) wrap round to ... -
I would like to write emulatorHi guys, I'm new to this forum but I realise that you must get loads of posts from people asking "how do I write an emulator" so I'll try and be spe…
... register (i.e. PC, SP, IX, IY) when we use the ... overflows, as do all the registers.
D ... -
On 48k, can I copy 4k before next screen updateFollowing on from my thread at [url="http://www.worldofspectrum.org/forums/viewtopic.php?topic=6423&forum=11"]http://www.worldofspectrum.org/forums/v…
...
POP HL ; using IX/IY registers too may or may not ... -
Index register subtractionHi, Just wondering if there a way to perform SBC HL,BC on the IX or IY registers. I can't find an op code for it, and my assembler doesn't recognise…
Sadly, it can't be done in a single instruction as SBC HL, BC is an ED prefixed instruction and the IX/IY opcodes don't work with any ED instructions.
You'll need to swap some registers I'm afraid!
Marko -
Assembler Interest?Any interest in an assembler supporting ACS's UV? I've built an assembler that: supports UV's syntax. has more correct parsing. Microdrive based…
... only be decimal literals, labels, registers or diplacements and there is ... , i.e. 50000, Label, bc,(ix+0) are all legal but ... -
DivIDE interface help neededhave got my DivIDE interface, CF adapter and CF 1 gig card all linked up, on a +3 I get the DemFir intro screen, good! Problem is I get no screen wha…
... /> FATware's tape emulator emulates registers IX, DE, Carry flag and even ... -
MC TipPlace your MC tip here: Here is my first: When using alternate registers (EXX) the HL register must not be affected on return to BASIC. Also the IY…
... - using the undocumented half IX and IY registers to get a few ... more 8 bit registers to use, although there is ... screendrawing code using the split IX and IY...)
_________________ ... -
length of 48k .sna fileJust a quickie :) Is the length of a 48k .sna 49152 or 49153, i.e. does it go from 0 to 49152, or from 1 to 49152? (If that makes any sense?) Cheer…
... and values (contents of all registers etc)
Offset Size ... word HL,DE,BC,IY,IX
19 - 01 byte Interrupt ... -
ZX80 software wanted for a ZX80 siteHi everyone - I'm putting together a site about the ZX80 - I've noticed there's virtually no software available for it on the net so that's the part …
... , is check the IX and I register. Normally, IX points to the ... set.
If these registers are not changed, the emulator ... file structure or modify the registers in another way that completely ... -
Basic or Machine code?Hopefully the correct area of the site to post this question. Anyways, I have got hold of several books on programming my spectrum, and I was wonderi…
... it does have the index registers which could be used in ... hassle would be to load IX with SP in the callee ... -
ANN: SP1 for Z88DK (aka splib3, Sprite Pack v3.0)Well it's finally arrived, after a month of "a few days from now" release deadlines. SP1 is the lastest version of splib, a flicker-free software sp…
... /> uchar res1; // +13 typically "LD IX,nn" opcode
uchar res2 ... is run to set up registers with the sprite properties (horizontal ... sp1_cs to execute where more registers are loaded with the (fixed ... -
When do you optimise?I was just wondering when people here optimise their code. Do they wait till it is all done or do they code a routine and then optimise that?
... more difficult because only certain registers can be involved in ... seen several compilers that use IX to index parameters in ... the penalty by using registers for up to two ... does it revert to using IX to index the stack. ... and again start using IX. Maybe. -
Sprite adviceHello. So, I'm slowly getting to grips with Z80 assembly - currently equal parts frustration and enjoyment. Now looking for some advice to help shift…
...
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
inc ix
ix/iy registers, but I don't ... -
Z80 vs. 8080.[QUOTE=obo]... because 8080 is pretty much just a cut down Z80.[/QUOTE] Really? So what's been cut, and why? Hang on, didn't the 808 evolve from the…
... 's also missing the index registers IX and IY, along with relative ... -
Restore Registers Returning to BASICI should really know this, but I've not written code that requires a return to BASIC for a loooong time. What registers need to be preserved / resto…
... . I don't use the IX/IY registers, so that's easy ... -
The Only Reason Sinclair Succeeded (Provoking Controversy)Although I love my Sinclairs dearly, I think that the only reason they succeeded was because at the time most people did not know any better (factori…
... ones that involve the IX and IY registers and I'd hope ... -
The Only Reason Sinclair Succeeded (Provoking Controversy)Although I love my Sinclairs dearly, I think that the only reason they succeeded was because at the time most people did not know any better (factori…
... hl register instead of the ix one where the instruction times ... to use the Z80s index registers in speed critical code.
The Only Reason Sinclair Succeeded (Provoking Controversy)Although I love my Sinclairs dearly, I think that the only reason they succeeded was because at the time most people did not know any better (factori…
... tape routines have utilised the IX register pair in time-critical ... never liked to use index registers on Z80 - probably because always ...Scrolling Loader CounterPlease can someone help me with writing a scrolling counter for a loading system. I like the Hewson counter so i`ve taken the font from zynaps loade…
... at adress pointed by IX
....
part1 ;store registers which are used by loader ... jump
;restore registers
jp return< ... ), hl
;restore registers
jp return
Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... done is a push ix so now the stack ... on the stack into registers before executing a CALL ... br /> (Incidentally, using the index registers to access stack parameters is ... stack and load up registers with parameter values. Also ... have no idea why IX is being pushed on ...Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... (Incidentally, using the index registers to access stack parameters is ... stack and load up registers with parameter values.[/ ... byte instruction), but INC IX is 2 m-cycles, ... a 2 byte instruction. IX+d operations are even ... slower - RL (IX+d) takes a whopping ...Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... try to avoid using index registers. Most people initially think of ... using any index registers.
I do use IX/IY all ... /> IX and IY are also handy as extra 8-bit registers by ... leave a lot of spare registers to do anything else, particularly ...Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... IX and IY register use like the plague. Instructions using these registers ... !! Anything you can do with IX and IY can be done ...Help understanding some z80 asmI'm trying to work out how to represent the structure of a "sprite" in the SAM as "Grabbed" by SmallC. I can see the assembler implementation but I …
... IX and IY register use like the plague. Instructions using these registers ... you can do with IX and IY can be ... going to be using IX to get passed data ... passing variables.
IX and IY are only useful ... a few more 8 bit registers to work with, although ...The 150 pound home computerWe missing out on this still ... I think. I know the PC market has wrecked all chance for any alternatives to ever have a hope but ... what if. :lol:…
... . In the new mode, individual registers are still 8 bit but ... BC, DE, HL, PC, SP, IX, IY are 24-bit. This ... because it could pair up registers and operate on them in ...The 150 pound home computerWe missing out on this still ... I think. I know the PC market has wrecked all chance for any alternatives to ever have a hope but ... what if. :lol:…
... . In the new mode, individual registers are still 8 bit but ... BC, DE, HL, PC, SP, IX, IY are 24-bit. This ... because it could pair up registers and operate on them in ...
