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Another Z80 processor questionOK, this time this isn't clearly covered in the FAQ, as far as I can see.... Suppose we have the CB instruction "SET b,r" (b=bit, r=register (differ…
Next one....
In a ... feature IO(x) in the "opcode broken into machine cycles" list ... -
InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... /> Internally, the Z80 divides every opcode into M-cycles; each M ... /> * M1: 4 tstates: read the opcode (0x34).
* M2: 4 tstates ... stack.
What happens next depends on the interrupt mode ... at the end of the next instruction, the NMI will still ... -
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…
... bit memory address of the next instruction, right?).
[quote ... frequency - and handily enough, each opcode takes a number of T ... -
Z80 register decoding document error?Hi, I've been working on a disassembler using the following document written by Cristian Dinu (aka GOC?). [url="http://www.z80.info/decoding.htm…
... 's actually one 8 tstate opcode which does nothing, rather than ... having to magically read the next byte in zero time to ... must be an 8 tstate opcode, not two 4 tstate opcodes ... -
Interrupt timingsHow long does the ULA hold /INT low for on interrupt on each of the Spectrum models?
... cycle into an INC C opcode. Any contention on the memory ... C from executing before the next interrupt occurs. I suppose it ... -
Emulator File types...SNA/TAP/TZX/Z80/ZXS All I knew about the Spectrum was how to play games on it, but since being introduced to pc emulations back in '97 I've always w…
... special opcode is inserted where the game would normally load the next ... would intercept this special opcode and load the next level data from ... from tape. The specific opcode chosen is one of the ... /> The special 2-byte "NOP" opcode was usually preceded by about ... -
Has this been done before?Are there any emulators whose speed can be adjusted by the Spectrum program that the emulator itself is running? So that, say the Spectrum program ca…
... into the next release of SPIN.
The unhandled opcode is ... -
Has this been done before?Are there any emulators whose speed can be adjusted by the Spectrum program that the emulator itself is running? So that, say the Spectrum program ca…
... off is going to be next to impossible to implement in ... off, or specify a custom opcode to be used instead.
XLR-8 mastering utilities - help wanted!!Hello. Ironic I know given I wrote them! I can't for the life of me get the XLR-8 mastering utilities to work under emulation. It goes through the m…
... changed the second "LD C," opcode into a "LD H,". So ... />
The first "LD C," opcode shouldn't matter as it ... a loop round for the next one. After that one potential ...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…
... *ulist; // +5 BIG ENDIAN ; next update struct in list of ... res0; // +8 "LD A,n" opcode
uchar e_hrot; // +9 ... res1; // +10 "LD BC,nn" opcode
uint e_offset; // +11 ...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…
... *next_in_spr; // +0 BIG ENDIAN ; next sprite char within same sprite ... res3; // +17 typically "CALL nn" opcode
void *draw; // +18 ... ; & sp1_cs.attr_mask of next sprite occupying the same tile ...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…
... *next_in_spr; // +0 BIG ENDIAN ; next sprite char within same sprite ... res3; // +17 typically "CALL nn" opcode
void *draw; // +18 ... ; & sp1_cs.attr_mask of next sprite occupying the same tile ...Emulator with ability to watch memory?Hi! I'm looking for an emulator that can give me a realtime update of an address in memory. I've tried Fuse (on OS X) where I can set a breakpoint i…
... /> Next question: does any other emulator besides DOS Z80 create 'opcode maps ...C# emulatorHi, I wanted to branch out and get a little better with C# so I think I need something meaty to do to keep me going....so an emulator seemed a reaso…
... /> [/QUOTE]
After every opcode, test the T-States counter ... more. So you start the next frame a few Ts in ...Features that emulators don't haveI believe most of us use more than one emulator, mainly because there isn't one emulator that has all the features we need or want to use. We also kn…
... head: T-States counting next to each opcode on debugger window (as ...Features that emulators don't haveI believe most of us use more than one emulator, mainly because there isn't one emulator that has all the features we need or want to use. We also kn…
... /> [QUOTE]T-States counting next to each opcode on debugger window (as ...Features that emulators don't haveI believe most of us use more than one emulator, mainly because there isn't one emulator that has all the features we need or want to use. We also kn…
... head: T-States counting next to each opcode on debugger window (as ...Whats an .SLT file?I found a website with a load of them on. Spectaculator gives no icon in windows explorer for them.
... hacked to contain a special opcode ("NOPD") which is an undocumented ... intercepts this and loads the next level data according to registers ...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 …
... SKIPS if yes, then skip next instruction.
ori #$F000,d1 ... next instruction
jmp INTER
[/code]
ISZ is an opcode ... next instruction if it overflows after 4095.
d0 holds the opcode ... . I do this with every opcode the pdp-8 has.
68000 programming.Anyone here know anything about this? My question is: how does the programmer know how long hisinstructions are? Do determine the operands to branch …
... SKIPS if yes, then skip next instruction.
ori #$F000,d1 ... next instruction
jmp INTER
[/code]
ISZ is an opcode ... next instruction if it overflows after 4095.
d0 holds the opcode ... . I do this with every opcode the pdp-8 has.
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
... w (a0)+,d0 put current opcode into d0.
move ... operand by 1. Skip next instruction if it overflows to ... /> addq #$2,a0 execute next command after that.
... to be dealt with till next round
JMPOP ...Z80 Developer ConsoleHi, This is a project I have meaning to do for ages, recently had a kid, had some time off work (as a software developer) and surprisingly had a bit…
My next change is that when a ... such as CALL from the opcode drop down, it lets the ...He's back......and he's got a new trick! AY Chip here. I've been away far too long. I would like to announce 'HatStand': for no adequately explored reason, I h…
... ...
4. K Cursor next to copyright message. Check your ... r,r' as the same opcode or not here?
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... be quite easily verified which opcode fetch is the first one ... the exact time until the next interrupt. Is this perhaps what ...Does anyone remember ftp.ijs.si?This is a blast from the past! I was going through some old files the other day and found this file:- [url]http://reptonix.awardspace.co.uk/sinclair…
... understand the LLT trap asm opcode (a hijacked undocumented NOPD instruction ... emulators to mean "load the next level from data file"). Recent ...Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... 't make difference for normal opcode fetches and memory access (saying ... counting the states to the next interrupt.[/QUOTE]
Actually ...Z80 Developer ConsoleHi, This is a project I have meaning to do for ages, recently had a kid, had some time off work (as a software developer) and surprisingly had a bit…
... 3) Actually you have used OpCode incorrectly - opcodes are the numerical ... you have entered a valid opcode(mnemonic) from the combo ... should be moved to the next value field.
...eg: ... /> 9) typing an incorrect opcode in the opcode combo causes an exception ...It's a trap!So I got a CPLD (not the eventual one I want to use for the ethernet project - rather, one I actually have here and now, an XC9536 in a PLCC44). And…
... monitors the data bus. The opcode for CALL, 0xF8 and 0x3F ... simple gate decoder). Then, the next time RD+MREQ do a ... bit "ripples along" into this next flip flop (and the first ...Emulators on the ZX SpectrumHaving released a Spectrum 16K emulator for Spectrum 48/128 machines as part of CCG2008, I was wondering if anybody knows of any emulators which actu…
... translation tables - one for M1 opcode fetches, one for memory read ... /> MAIN LD A,(DE) ; Fetch opcode
LD L,A
next command
[/code]
Spin problems/issuesI am running Spin 0.666 and have noticed a few issues (some are bugs, some might be just me). I am using Vista sp1 (yeah I know!), and I've seen Dunn…
... contains the RST 28 ($EF) opcode.[/quote]
Haven't been ... assemble your instruction once the next version is released either, because ...
