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Scrolling loader counter in 85 T-States?Would it be possible to write a scrolling loader counter in 85 T-States? I have a custom screen load routine that loads attribute first, then the …
... 'm only using a and IX registers, I've timed each route ... ; retrieve attribute address
inc ix ; 10ts ; next attribute
... code.
Registers used by loader are IX, DE, HL, BC ... ,AF'. So a and EXX registers can be used. I want ... -
Machine Code: quicksort optimisationI came across this z80 quicksort implementation when going through the wikipedia article on the same. It's 44 bytes long. I was wondering if any of …
... /> ; HL = size of array
; IX = cmp function (DE=key, BC ... /> ; MUST PRESERVE BC,DE,HL,IX registers)
; exit : array sorted
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…
Only a cretin would use the IX registers in a time critical piece of code. JamesD would never make a decent Spectrum programmer.
Face facts James, the Spectrum is a more powerful machine than the C64.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…
... a cretin would use the IX registers in a time critical piece ...Sprite Tutorial: Section on Masked Sprites addedLatest installment of my Sprite Graphics Tutorial: [url="http://members.aol.com/derekmsmith1/Spectrum/TUTORIAL.RTF"]http://members.aol.com/derekmsmi…
... relating to use of the IX registers.
Is this a ... allow the use of these registers ??
Nice Tutorial BTW ...Sprite Tutorial: Section on Masked Sprites addedLatest installment of my Sprite Graphics Tutorial: [url="http://members.aol.com/derekmsmith1/Spectrum/TUTORIAL.RTF"]http://members.aol.com/derekmsmi…
... relating to use of the IX registers.
Is ... allow the use of these registers ??
Nice ... code that uses the ix register, and assembles in ... UpdateCoords
ld a,(ix+2); update the old co ... sprite frame
ld (ix+6),a
ld ...Sprite Tutorial: Section on Masked Sprites addedLatest installment of my Sprite Graphics Tutorial: [url="http://members.aol.com/derekmsmith1/Spectrum/TUTORIAL.RTF"]http://members.aol.com/derekmsmi…
... that contain
ld (ix),a ( upper or lower case ... all that sure about the ix registers :)Sprite Tutorial: Section on Masked Sprites addedLatest installment of my Sprite Graphics Tutorial: [url="http://members.aol.com/derekmsmith1/Spectrum/TUTORIAL.RTF"]http://members.aol.com/derekmsmi…
... that contain
ld (ix),a ( upper or lower case ... all that sure about the ix registers :)[/QUOTE]
Right, in ...
[code]
ld (ix+0),a
[/code]
New Spectrum Game - AlbatrossityMerry Christmas, and all that. Here's a little Christmas present for Spec-chums everywhere. Albatrossity is a crazy golf game which doesn't take it…
... the few which corrupts the IX registers. It seems I'd forgotten ...SNA convertHi Can a .sna be coverted to .tzx and would there be any point ?
... you
set back the IX registers to match loading with actual ... not overwrite. After loading all registers must be set and a ...ALIEN (Mindgames) Bugfix and Improvement.[code]ALIEN (Mindgames) [ZX SPECTRUM] BUGFIX & IMPROVEMENT by Ersh 2016-10-29 The following bugs are fixed: [BUG] INVENTORY BUG WHEN SWITCHING …
... didn't PUSH/POP the IX registers holding the
pointer to ... destroyed the register pair, thus IX would hold
the wrong ...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…
... loooong time.
What registers need to be preserved / restored ... machine code? I recall that IX needs to be preserved (or ... to restore:
[LIST]
[*]Registers (which ones)?
[*]I register ...Reading AY registersCan anyone with a real machine confirm or deny the statements referenced in this [url="http://sourceforge.net/tracker/index.php?func=detail&aid=91120…
... the AY-3-8912's registers (and/or for the YM2149 ...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] ; ***********…
... Start
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 ...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…
... HL,BC on the IX or IY registers. I can't find ... to work on the index registers but not SBC.
"Add Watch" Debug for EmulatorsHi, I am working on completing a JSW-style game that I started in 1991. Although programming using TASM and Spectaculator is far easier than on th…
... memory pointed to by (HL), (IX) and (IY)) a bit of ... a facility (only to watch registers directly).
Can anyone ...A few questions about machine codeOh no... another noob. I'm giving my first steps in assembler (finally, after 20 years stuck in BASIC). I read a SU article explaining that if I wan…
... carry flag before setting the registers. Now, if I'm ... ld a,255
ld ix,16384
ld de,6912 ... /> ld a,255
ld ix,24576
ld de,22564 ... don't understand why certain registers have to be used ... . works. I still see registers as BASIC variables, and I ...How to read AY Registers from M/C?Gentlemen, I will appreciate if you can provide me some details on this, as I could not find info in other sources. I would like to know if it's pos…
... , and how, to read AY-Registers like the mixer. I tried ...So... you want to format your 3.5" as 720K eh?Well, i've been trying to get hold of an application to make proper use of my 3.5" +3 floppy disks but i haven't been able to find any. I stumbled up…
... /> INC IX
INC IX
INC IX
... br /> LD IX,XDPB ; Point IX to the extended ... POP BC ; Restore the registers used
RET ; ...Questions about registers, stack, etc.I was told that if I wanted to export code and create unprotected versions of games I should do the following: 1-Find the starting address by using …
... /> 4-Make a note of registers/stack
5-Create a ...New Spectrum Computer DevelopmentHey does anyone know of any decent new Spectrum clones being developed? I find it amazing how Zilog still produce a Z80 backwards compatible chip (an…
... unit, by extending most registers (HL, BC, DE, IX, IY, PC, and ...Rainbow Generator for 48K Spectrum using PUSHThis is what I came up with from [B]gasman[/B]'s suggestions. It's stable in ZXSpin and ZX32 simulating a 48K Speccy. Anyone like to try it on the …
... /> interrupt_main
;Save all registers, then save
; the Stack ... br /> push hl
push ix
push iy
ld ... push af
exx ;Exchange registers for alternates
ex af ... br /> pop iy
pop ix
pop hl
pop ...How feasible is it to add a second CPU to the ZX Spectrum?Today with IDE, and USB, and TCP/IP and other wonderful technologies arriving on the ZX Spectrum, I'm beginning to wonder if we'll run out of CPU tim…
... write into the CPU registers AF, BC, DE, IX etc also? Or ...Tinkering with Quique Llar?a's Midi2Ay tool...Im tinkering with Quique Llar?a's Midi2Ay tool, found at: [url]ftp://ftp.worldofspectrum.org/pub/sinclair/tools/pc/midi2ay-0.1.zip[/url] Im not a v…
... making copies of all the registers at the program start and ... ),ix
pop ix
push ix
ld (R_PC),ix
ld ix ... ,(R_SP)
ld ix,(R_PC)
push ix
ld ... iy,(R_IY)
ld ix,(R_IX)
RET[/QUOTE]
Using the stack to copy memory blocksA [b]PUSH[/b] and a [b]POP[/b] instruction together take less time than two [b]LDI[/b], so long [b]POP/PUSH[/b] sequences are sometimes used to copy …
... /> [code] di
ld ix, source
ld hl, dest ...
start:
ld sp, ix ; 10 T
pop bc ... = 54
add ix, de ; 15
add hl ... benefit of using 16-bit registers.Shadow registers.I assume it's faster to transfer the registers to the shadow registers rather than using the stack? Let's say that I want to temporarily preserve the…
... faster to transfer the registers to the shadow registers rather than using ...Help pleeease "Proving Emulator OpCode flags are correct"So I had a cunning plan... I wanted to write a test harness for Emulators that could "prove" that all opcode flags were correct. I wanted something m…
... ,0x7000 //mcAddr, lAddr
LD IX,0x8000 //xAddr
LD B ... /> LD (HL),D
LD (IX+0),E
RET
registers for every opcode)? Doing this ...Byte-order backbufferThis is a tool for Z80 coders who wish the Spectrum screen had a serial layout. It runs as an interrupt mode 2 service routine and uses POP and PUSH …
...
push af ; save the registers
ld a, 0x3b ; high ... /> push af ; save all registers and the stack pointer
ld ix, attributes + 768 - 16 - (attr ... and all registers
pop iy
pop ix
...IX register woes - or is SPIN buggy?Or am I missing something? I'm trying to use the IX reg to acess a table containing an x and y coord. My code below just doesnt seem to work proper…
...
ld a,(ix)
but it ... likes ld a,(ix+0)
im ... if when im using (ix+1) its really adding ... ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
SHPMOV
ld ix,shptbl ;point to ship table ...
