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"Decoding z80 Opcodes" (http://www.z80.info/decoding.htm#intro) - Incorrect HALT Opcode?Apologies if this is a dupe but I searched within the forums and couldn't find anything. I've been working on a z80 emulator (for academic and rec…
... seems to incorrectly specify a HALT opcode as 0x7[i]7 ... -
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…
... ). I use an often neglected instruction, [b]CPIR[/b], for this ... ;a short pause
3$ halt ;before
djnz 3$ ;leaving ... -
Instruction sheets, manuals and other items!Has anyone got the following instruction sheets, manuals and/or other items: After Burner Sticker Double Dragon 2 Poster Rick Dangerous Instruct…
Has anyone got the following instruction sheets, manuals and/or ... Poster
Rick Dangerous Instruction Poster (have the comic)< ... br /> Star Raiders II Instruction Sheet for Spectrum
... Tau Ceti Instruction Sheet
Any ... -
FOR loop without NEXT instruction. How come?I've been looking through the BASIC listing for M.C. Lothlorien's Red Baron and have noticed a line of looping code that is puzzling me. This is lin…
... had to have a NEXT instruction yet the second FOR j ... -
CODE instruction in array$ PRINTSo I'm still plugging away at BASIC and have found a line of code (another!) that's really puzzling me. The line is as follows: PRINT A$(P+Q TO P…
... /> However, there's a CODE instruction in there and I don ... am misundertanding how the CODE instruction works or I've made ... -
Which Emulator has a menu option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT?Which Emulator has a menu option / debugger option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT? I tried SpecEmu and Fuse, b…
Which Emulator has a menu option / debugger option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT?
I tried SpecEmu and Fuse, but I can not find a option for doing this in their debugger. -
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:/…
... , Res(6, IY/IX+n) instruction. (woody)
- Fixed MIC boost ... snapshot (woody).
- Fixed incorrect HALT implementation (ZjoyKiler).
- Fixed incorrect ... -
Easiest way to figure instruction lengthGiven a start address, what is the easiest way to find out instruction length at that address in Z80? I found [url="http://www.z80.info/decoding.htm"…
... easiest way to find out instruction length at that address in ... -
Is it possible to make the Z80 execute a bizarre instruction?What happens when it gets an unrecognised instruction OP Code, I mean something following a #ED that isn't one of the undocumented instructions eithe…
... when it gets an unrecognised instruction OP Code, I mean something ... -
Here's a christmas present for you!SE Basic is no longer being developed.
... removed the timings (TSTates per instruction) and just taken the interrupt ... it can, whilst still maintaining HALT timing and FLASH stuff. PAUSE ... -
Fire Ruby - More HelpI cant pass the spikes in the fire ruby by lawrence creighton, can someone please help? [ This Message was edited by: welsh_brawler on 2003-08-08 21…
... {6}& splutters to a halt. "Cripes"{6}says Wally, "I ... name and a one-word instruction.{6}{6}{6}{16}{6 ... -
VSYNC FunctionI have written a VSYNC function, so that I can clear the screen before redraw without flicker on the screen, I do this by peeking at the address 2367…
... fool, all I needed was HALT, Aghhhhhhhhhhh
So many ... beginning of the first instruction after the halt. You'd save time ... -
VSYNC FunctionI have written a VSYNC function, so that I can clear the screen before redraw without flicker on the screen, I do this by peeking at the address 2367…
... program was in assembly? Would HALT serve the purpose then?
instruction following a halt will be executed around ... this thread (prior to the halt) was reading the frames system ... -
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 …
... +1),HL ; Modify the JP instruction with appropriate address
; for ... for sprite drawing
HALT
CALL DRAWSPR ;Call sprite ... -
FrameSyncIt was many many years ago since i programmed assembly on the spectrum but I just picked it up again for fun. Now this is one thing I can't remember…
Using Halt is fine for this sort ... at some point if using halt, otherwise you would never get ... your routine, ie. the instruction imediately following HALT.
If you ... -
finding largest value (z80 assembly)suppose we have to write z80 program which requires to find the biggest value in a block of memory starts from the address 101h until address stored …
... />
ld (200h),a
halt
[/code][/QUOTE]
ld ($200),a
halt
[/code]
But ... 't right. The "cp (hl)" instruction will set C (the carry ... -
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…
... />
[code]
spritedrawroutine
halt
ld ix,spritehltab ... />
[code]
spritedrawroutine
halt
ld ix,spritehltab ... fact, the ld l,(ix) instruction alone is enough for the ... -
R Register, Contended RAM and ClonesHi. I've had a quick look at the CSS FAQ but didn't spot quite what I'm looking for (also the CSS FAQ doesn't have much detail of the clones - there …
I don't think that HALT waits longer - it is triggered ... after each instruction, if I remember correct. While in HALT, CPU performs ... -
R Register, Contended RAM and ClonesHi. I've had a quick look at the CSS FAQ but didn't spot quite what I'm looking for (also the CSS FAQ doesn't have much detail of the clones - there …
... of the contended RAM. Each instruction executed should take the same ... the memory model. The HALT increments the R-register for ... accessed during the frame, then HALT will execute a different number ... was initially assuming that a HALT would increment the R- ... -
How does interrupts work?I am a little confused regarding the interrupts on the Spectrum. If I have some hundred bytes of machine code started with, say, [B]RANDOMIZE USR 300…
... anything useful with the XOR instruction itself?
Could the ... opcode 118 which is [B]HALT[/B] rather than the more ... -
Project: M.u.l.e.Wokani came up with a great idea about trying an open-development approach for spectrum games, and I thought why not try with a game I have under dev…
... exactly to put the halt statement and how to ... bpoke(0xd1d1, 195); // POKE jump instruction at address 0xd4d4 (interrupt service ... isr address following the jump instruction
#asm
... lines poke a JP instruction at address 0xd1d1 that ... -
68000 programming.Anyone here know anything about this? My question is: how does the programmer know how long hisinstructions are? Do determine the operands to branch …
... by one, and skip next instruction if 0
0003 5000 ... 0000
0004 7402 hlt ;halt processor.
0005
0006 ... operand by 1. Skip next instruction if it overflows to 0 ... #9,D0
TRAP #15 Halt Simulator
END START ... -
Questions about the Speccy and it's emulationOut of interest, and to raise another interesting discussion, I have some questions about the Spectrum and it's emulation; 1) Is everything known ab…
... bus code with a [b]halt[/b] instruction, which has the crude ... -
Has any programmers recently pushed the spectrum to the limits?Hi there. Ive just discovered this great forum and I was brought up with the speccy 16,48 and then 128k. Im just wanting to know if there are any re…
... /> LD B,L
TSLP3 HALT ; Hang around, modifying the instructions ... bytes of attribute data - the instruction data encodes the attributes, modify ... -
The Goldfinch updates thread([url=http://www.worldofspectrum.org/forums/showthread.php?t=25034]original announcement thread here[/url] - I figured it was worth starting a new to…
... see that incrementing after a HALT you know you're in ... after a LD A,I instruction.) It's also interesting to ... -
Why did Ultimate games load like this?What I remember about the early Ultimate games was the unusual way they loaded. You'd get the BASIC bootstrap loader, then a SCREEN$, then a main bl…
... when it comes across a HALT at $1303 (just like the ... address contains a JP (HL) instruction. This address is called all ... -
Pretty CrashesTo make a 48K spectrum crash spectacularly and beautifully enter the following into basic. Also works on a 128k in 48k mode though not quite as prett…
... upon to interpret as an instruction. So, the worst that can ... /H/HCF.html]Halt and Catch Fire[/url] instruction on the Z80 ... -
Pretty CrashesTo make a 48K spectrum crash spectacularly and beautifully enter the following into basic. Also works on a 128k in 48k mode though not quite as prett…
... upon to interpret as an instruction. So, the worst that can ... /H/HCF.html]Halt and Catch Fire[/url] instruction on the Z80 ... it talks of the IM instruction and says [B]"Under no ... circumstances use this instruction"[/B] but does not say ...
