-
Fastest way to mirror a byte?I.E. turning 01100000 into 00000110, in assembly. I'm trying but I suck at stuff with rotation and the carry bit. Any pointers?
... location (SP) and HL.
EX (SP),IX Exchange the location (SP) and IX.
EX (SP),IY ... Exchange the location (SP) and ... -
z88dk sticky?I've just tried to PM Alcoholics Anonymous and couldn't because "Alcoholics Anonymous has exceeded their stored private messages quota and cannot acc…
... for inapplicable functions.
IX is reserved as FILE*/FD ... structure can be addressed using IX+n indexing and sending/forwarding ... . The device driver can than 'ex (sp),ix' to get hold of its ... the caller is then 'pop ix; ret'
Regarding ... -
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…
... also do:
[B]EX DE,IX[/B]
and [B ... ]EX DE,IY[/B] ?[/QUOTE]
< ... only one that works with IX is [B]EX (SP),IX[/B]. -
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…
... one that works with IX is [B]EX (SP),IX[/B].[/QUOTE]
DK Tronics Compilation Tapes....MIA ??I have two tapes (no inlays) of compilaitons of DK Tronics games. One is from DK Tronics themselves, has a white label with black text, and contains…
... /> 16389 PUSH HL
16390 EX (SP),IX
16392 XOR A
16394 EX AF,AF'
16395 LD SP,65302
16398 ...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 hl
ex af, af' ;'
exx ... bc
pop af
ex af, af' ;'
exx ... in IY -16
ld sp, ix
pop af ; read ... de
pop hl
ex af, af' ;'
exx ...
push af
ex af, af' ;'
exx ...Optimisations in Exomizer Z80 decrunch codeThis is the 163 bytes old code (simple and optimized): [CODE] ld iy, exo_mapbasebits ld a, 128 ld b, 52 push de exo…
... ;hl=origin
push ix
pop bc ;bc= ... call exo_getpair ;bc=offset
ex (sp), hl
ld d, h ... ;hl=origin
push ix
pop bc ;bc= ...Zero 0.5 ReleasedAfter a bit of a hiatus, the next update of Zero is now available [URL="www.ramtop.wordpress.com"]here[/URL]. Feedback and bug-reports appreciated! …
... ).
- Fixed timing for EX (SP), HL/IX/IY instructions (Woody).
- Fixed ...LZ4 decoderI encountered the [URL="http://code.google.com/p/lz4/"]LZ4 compressor[/URL] a few weeks ago. Reading the [URL="http://fastcompression.blogspot.co.uk…
... in BC. Does not use IX or IY. Uses the ... copy of the token
ex af,af' ; move token ... many bytes
ex af,af' ; switch token back ... additional length if so
ex (sp),hl ; switch destination pointer ...Ghosts n' Goblins loaderI'm trying to put Ghosts n' Goblins onto a +3 disk but struggling to understand the mc loader. Basic loader [code] ink 7 : clear 25000 : load "" cod…
... /> 65122: JR 65161
65124: EX AF, AF'
65125: JR ... /> 65155: INC IX
65157: DEC DE
65158: EX AF, AF ... /> 65240: EXX
65241: LD SP, IX
65243: PUSH BC
65365: JR 65408
65367: EX AF, AF'
65368: JR ...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 …
... /> ; MUST PRESERVE BC,DE,HL,IX registers)
; exit : array ... /> ld (bc),a
ex af,af
ld (hl ... />
ld a,(bc)
ex af,af
ld a ... br /> ld h,b
ex de,hl ; de = left+1 ...Oh so BRIGHT!What is the SLOWEST way to change the attribute area to BRIGHT? It has to be legit! No meaningless instructions or doing stuff for the sake of it. …
... br />
ld ix,22528
attrloop: ... add iy,sp
ld sp,ix
ex (sp),hl
ex (sp),hl
ld sp,iy
help sought with first foray into machine code - pixel scrolldownI have started to code my first machine code program, a simple roadrace game. I've based it around the pixel scrolldown routine in 40 Best Machine Co…
... I need some horrible 'ex(sp), hl'-type instructions ... br />
ex (sp),hl takes 19 cycles ... .destination
ld sp,0 ; to be filled in ... perhaps the push ix/pop ix actually slows things ... The "ld sp,hl; ld sp,ix; ld sp,iy" instructions ...Understanding the StackSorry folks. I guess I'm going to be a pain for a little while. Hope it's ok with everyone. I'm currently studying the stack and wrote the little pr…
... use IX:
[code]
ld ix, 2
add ix, sp
pop ix ; my_addr structure
ex (sp), hl ; restore return addr ... here is the last instruction, EX (SP), HL. This just swaps whatever ...AY programming and notes frequencyHello everybody, I'm Targhan from the french CPC group Arkos, perhaps you've heard of us. I'm currently working on a music tool and I'd like to k…
... :
ld (pdsp_+1),sp
ld sp,ix
ld h,a ... ),sp
ld l,(ix+00dh)
ld h,(ix+00eh)
ld sp ... /> ld (ix+009h),h
ch_noac:
ex de,hl
ex af ... /> ld sp,03131h
ex (sp),hl
xor a
or (ix+005h ...AY programming and notes frequencyHello everybody, I'm Targhan from the french CPC group Arkos, perhaps you've heard of us. I'm currently working on a music tool and I'd like to k…
... :
ld (pdsp_+1),sp
ld sp,ix
ld h,a ... ),sp
ld l,(ix+00dh)
ld h,(ix+00eh)
ld sp ... /> ld (ix+009h),h
ch_noac:
ex de,hl
ex af ... /> ld sp,03131h
ex (sp),hl
xor a
or (ix+005h ...tricks to simplify codingWhen i started with programming in assembler i had very simple approach to do things. Just shifting bytes around, doing simple tests and so... Later …
... function address
ex (sp),hl ; hl = message parameter
IX,nn" opcode
uchar ... hl,graphic_address
ld ix,graphic_address_char_to_left_of_this_one
call sprite_draw_function ...Spectrum 128K RS232 to PC serial cableIf you have read some of my recent posts then you will know that I am eager to link my Spectrum +3 to a PC. This will be done by wiring a standard PC…
... /> ex (sp),hl
ld (r_pc),hl
ex (sp),hl
ld sp,r_r ... />
; > IX = Return address
; >'HL ... nz,rbyte
jp (ix) ; Return
; ...yeah - unix for zx spectrumI started a new hobby project. An operating system for ZX Spectrum. A unix clone. Talked to my friend about it and he asked me what if after I'm done…
... absolute addresses, loading up SP and performing a task ... iy
60 pop ix
61 pop hl< ...
75
76 ex (sp),hl
77 push af ... hl
86 push ix
87 push iy< ... stack
; save SP in task structure
; perhaps ...AY Magic version for ZX81 was bornModified Ay magic ,my previous interface for zx48. On board, ay chip based on Zonx interface but with stereo output and rampack 16 or 32 kilo on boa…
... :
ld (pdsp_ + 1), sp
ld sp, ix
ld h, a ... /> set_stp:
ld (ix + 12), a
ex af, af'
ld ... ), sp
ld l, (ix + 13)
ld h, (ix + 14)
ld sp ... /> ld sp, 03131h
ex (sp), hl
xor a
or (ix + 5 ...Kobrahsoft DB1 - doesn't work?Hi, I've tried loading [URL="http://www.worldofspectrum.org/infoseek.cgi?regexp=^DB1$&pub=^Kobrahsoft$&loadpics=3"]DB1 by Kobrahsoft[/URL] into two …
... /> XOR B ; 8007 A8
EX (SP), HL ; 8008 E3
XOR ... /> DI ; 8018 F3
LD IX, $4000 ; 8019 DD 21 00 ...writing an emulator-newbie needs helpHi, this is my first post here. I decided to write a minimalistic emulator of ZX Spectrum-no emulation of advanced peripherals, no emulation of sound…
... say SP=16385 and PUSH IX is about to be executed. SP-1 ... half of IX be placed on a stack? Would SP be decremented ... of where SP points to?
Another example: EX (SP),HL. What ... if SP points to an address ...Need help with tzxingI recently got a copy of this Polish text game: [url]http://www.worldofspectrum.org/infoseekid.cgi?id=0006622[/url] I can't make a tzx of it howeve…
...
[CODE]EXX
LD IX,L49600
LD DE,(23635 ... ,L49465
BIT 0,(IX+0)
JR NZ, ... /> NEG
ADD A,(IX+51)
SUB (IY+ ... 0)
ADD A,(IX+52)
DAA
... /> LD HL,L49650
EX (SP),HL
JR L49557
Fairlight's use of LDIRYS, comparing Fairlight and Nightshade, said: [quote]Fairlight is much more interesting even though the techniques that Bo Jangeborg uses for screen…
...
push hl
ex af, af' ;'
exx ... bc
pop af
ex af, af' ;'
exx ... in IY -16
ld sp, ix
pop af ; read ... de
pop hl
ex af, af' ;'
exx ...
push af
ex af, af' ;'
exx ...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 hl
ex af, af' ;'
exx ... bc
pop af
ex af, af' ;'
exx ... in IY -16
ld sp, ix
pop af ; read ... de
pop hl
ex af, af' ;'
exx ...
push af
ex af, af' ;'
exx ...number padding functionI wrote a number padding function in BASIC a while ago, but when I came to want it again I couldn't find it, so I've done this enhanced [url=http://w…
... $2bf1 ;STK_FETCH
pop ix ;IX=(DEFADD)
ld a,"E ... pop de
ld a,(ix+12) ;A =maximum integer ... pop hl ;HL=$000D
ex (sp),hl ;HL=$106E
push ...z88dk vs. sdccI've just read this article (in Spanish) [url]http://www.cpcmania.com/index2.asp?urldest=Docs/Programming/SDCC_vs_z88dk_Comparando_tama%F1o_y_velocid…
... a few things: they use IX as function pointer (standard functions ... .
sdcc reserves IX as frame pointer (it also ... br />
[code]
push ix ; maybe not done for __naked ... bc
pop de
ex (sp),hl
asm_memset:
In Java for ZXHi All I am glad to notify you that I have opened the sources of my J2Z80 translator (0.1 version) which allows to use Java toolchain to generate Z8…
... SP,IX ; write in SP the first cell
INC SP
INC SP ... /> LD SP,IX ; write in SP the first cell
EX (SP),HL ; the ... return address restored
EX DE,IX ; the old IX restored ...Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... br /> pop de
ex (sp),hl
asm_itoa ... br /> ld ixh,d ; ix = char * (current write ... ; bc = radix
; ix = char * (current write location)
; ix = char * (current write location ...
