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Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
... DEC B already sets your zero flag which is tested by JR ... -
Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
I've seen this before a lot when using BC register so I assumed B doesn't set zero flag.
DEC BC
LD A, B
OR C
JR NZ, LOOP -
Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
... assumed B doesn't set zero flag.
DEC BC
flag. This proviso doesn’t apply ... ]not[/i] set the Z flag, DEC B or DEC C ... -
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…
... A ; this clears the carry flag, does not change A
XOR A ; this sets zero flag and sets A=0
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…
... A ; this clears the carry flag, does not change A
XOR A ; this sets zero flag and sets A=0
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…
... nc, .notatline24) instead of the zero flag. You may need to do ... 1 I check the zero flag not the carry flag I think.
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…
... nc, .notatline24) instead of the zero flag. (May need to cp with ... 1 I check the zero flag not the carry flag I think.
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…
...
jumps if the zero flag is set (and does not ... />
ret z ; return if Zero flag is set
EDIT ... z, func ; call func if zero flag is setHow 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…
... 32) and checks the carry flag (JR NC -> jump if ... carry flag not set) instead of the zero flag.
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…
... /pop method.
Carry/Zero flag for a bool return value ... also ;)
The carry/zero flag trick I remember using back ...Console frameworkStill working on Specotron, but at the point where working out the diagonal lines collision is not good at beer o'clock. In the meantime I've knoc…
... .
Unless I return with zero flag clear if "an invalid combination ... ). I think it also sets zero flag if you are only pressing ...ZERO Emulator - BugsI have been using Zero emulator to experiment a few routines in assembly, since it has a somewhat usable debugger. However I believe I found a few b…
I have been using Zero emulator to experiment a few ... a few bugs, some in "zero" application, and some on emulation ...SUB and the S flagGuys, if I use SUB to take a value HIGHER than is currently in A, does the S flag get set? I know that N does. [code] LD H,33d LD A,32d SUB H …
... in A, does the S flag get set? I know that ... test if A goes below zero?
I'm trying ...Zero v0.8Pigs can apparently fly because it's the v0.8 update of Zero that no one asked for but is out for public consumption anyway. Grab it [url="https:/…
... the v0.8 update of Zero that no one asked ... [url="https://github.com/ArjunNair/Zero-Emulator/releases/tag/v0.8 ... .
* Changed the way Zero attempts to load ROMs if ... issue (rich_chandler).
- Fixed parity flag being incorrectly reset during interrupt ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... IFF2 to the P/V flag) is interrupted, then the P ... /V flag is reset, even if interrupts ... (23728) if it was non-zero. Unfortunately, the test was reversed ... and only if it was zero (thus causing a reset). However ...Smooth Screen Scrolling RoutineHi everyone, this is a follow up to the thread on smooth screen scrolling. As promised here is the code for the routine. It's pretty long and fairl…
... A
LD (BLFLAG),A ;Flag used to indicate
;if ... .
LD (BLFLAG),A ;set Flag to indicate a blank.
DJNZ CLEARLP2
JP ZERO ;Skip the next bit which ... ;DE = SCREEN ADDR.
ZERO LD HL,(MODHLB+1) ;Move ...Outrun vs Chequered FlagIn the latest issue of Retro Gamer its stated that Out Run was the first racer to have undulating hills etc. I reckon Chequered flag was, however cra…
... hills etc. I reckon Chequered flag was, however craply done. Let ...Need help with my P flag!Not sure if I've emulated the P flag correctly when its comes to overflows. Here's what I've done: LD A,123 LD B,16 ADD A,B Twos Complement of 123 …
... I've emulated the P flag correctly when its comes to ... I've done the overflow flag right.
Thanks in ...Bulk games for saleGot a huge box of games for sale, postage would probably be a fair bit, if anyone lives local or likes to drive long journeys then you are free to pi…
...
Spectrum Safari
Chequered Flag
Flight Simulation
Chess ...Zero magazine scans/mags available?Hello. Offtopic for a Spectrum forum I know but does anyone (Mort! ?) have scans available for the Zero series of magazines? It was the old Dennis P…
... ! ?) have scans available for the Zero series of magazines? It was ...SimCoupe 1.0 released[size=-2](for those of you that don't read CSS)[/size] SimCoupe, the SAM Coup? emulator, has been updated to version 1.0. This major release adds ma…
... HL,rr incorrectly setting N flag
- Fixed ADD IX/IY ... carry for overflow, or H flag
- Fixed disassembly of IN ... 15, which were always returning zero
- Fixed mouse read timeout ...In Machine Code, what is the quickest way to sort bytes?I am playing around with some ordering of sprites, where I want to order them by vertical position. I used some Rodnay Zaks code to order some bytes…
... ; ix=(hl)
res flag,h ; exchanged flag=0
ld b ... into next
set flag,h ; exchanged flag=1
... ; dec b, continue until zero
bit flag,h ; exchanged=1?
RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... and a ; clear the carry flag before
; calculation
flag
and a ; test against zero
... zero
ld (atflg),a ; store in AT flag ... to zero
ld (atflg),a ; clear AT flag
flag
pop hl ; ...Question on Z80 R/W cycles.Snipped from the complete spectrum ROM disassembly: [CODE] Now the memory is checked. 11DA RAM-CHECK LD H,D Transfer the value…
... /> SBC HL,DE The carry flag will become
ADD HL ... ,11EF,RAM-DONE But if zero then RAM is faulty.
Zero is set, right?
But ...Union flag on Sabre Wulf game boxLooking at this pic, I noticed that the Sabre Wulf box has a Union flag style sticker on it: [url]http://www.digitalarcade.co.uk/speccy/DSC05157001.…
Any "Capture The Flag" games?There used to be a really good DOS game called Capture The Flag which featured two teams of players starting in a land area split in two. The object …
... DOS game called Capture The Flag which featured two teams of ... to capture each other's flag, moving players in turn across ...Overflow Flag QuestionHello all, After a long hiatus (lost all code when my MacBook was stolen) i've gone back to the drawing board and am writing a Z80 emulator in REALb…
... a question about the overflow flag.
I am using ... . This means that my overflow flag is being set when it ...'Ground Force Zero'This is very spooky...I've just been going through some of the Spectrum games we got in recently and have come across one called: Ground Force Zero. …
... across one called: Ground Force Zero.
The cover shows ...
