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Why Hex in place of Denary?Ok - most MC books / tutorials advocate the use of hex instead of denary. But the Speccy doesn't actually have a Hex converter so you need to write …
... 30004. 117 translates to an opcode LD (HL),L, so your ... -
Announce: EmuZWin 2.4.1.0 with exact AY soundEmuZWin 2.4.1.0 with exact AY sound released today. In "exact sound" mode, should be very, very close to real sound. (My ears are sick, my head is sp…
... the port address for that opcode?
That demo runs ... -
Announce: EmuZWin 2.4.1.0 with exact AY soundEmuZWin 2.4.1.0 with exact AY sound released today. In "exact sound" mode, should be very, very close to real sound. (My ears are sick, my head is sp…
SpecEmu 2.1 betaFinally I think I've cracked all the gory contention details required by those trendy multicolour demos (48K/128K modes only, +3 contention can wait …
... invaluable and all the extra opcode contention has now been corrected ...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…
... 0xBFBF
ld (hl),0xC3 ; opcode for JP
ld hl ...+D/Disciple games archive?Hi all, Having finally got my disciple to work, I'm starting to have a look at hacking multiload games. Is there any archive on the web with games t…
... . The hack is a special opcode -- the "NOPD" instruction $ed $?? inserted ...Z80 processor question...Suppose we fill the entire $0000-$ffff memory range with $ed. What will the processor do ? I suppose it will get locked, but will it still respond to…
... the second as an alternative opcode type. The second EDh byte ...Z80 processor question...Suppose we fill the entire $0000-$ffff memory range with $ed. What will the processor do ? I suppose it will get locked, but will it still respond to…
... EI opcodes until after the opcode following the final EI.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…
... the unofficial versions of the opcode.
[quote]
My ...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…
... 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 ... bus value (0xff), coincidentally the opcode for RST 38, so the ... data bus means a random opcode could be executed, which makes ...Z80 core testing ?OK, my z80 core is almost finished (apart from RRD, RLD, and block instructions except LDI,LDIR,LDD,LDDR). I run the 48K rom and hurray, it resets co…
... one test for every Z80 opcode. You'll need to write ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... IM 0 depend on which opcode is executed; if there is ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... T states: 5 for an opcode fetch, 3 for pushing PC ... />
But there is no opcode fetch performed in an interrupt ... memory so the 5-cycle opcode fetch is out. You can ... peripheral supplies the "RST n" opcode. This is followed by the ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... 2 because placing an instruction opcode on the bus is a ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... because placing an instruction opcode on the bus is ... understood to mean an opcode fetch cycle (called that ... M1 goes low when an opcode fetch cycle happens). But ... n" has 5 cycles of opcode fetch (OCF) from memory ... time the "RST n" opcode is supplied by the ...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…
... of loop that takes an opcode per loop and executes it ...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…
... of loop that takes an opcode per loop and executes it ... one for every non-NOP opcode. Each test contains the state ... Z80 before and after the opcode; by seeing where your code ...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…
... code that can take an opcode (whether as an integer, string ...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…
...
decode the opcode as per GOC's table ... space for various parameters the opcode will expect.
... Perform the opcode's operation, and increment your ... frequency - and handily enough, each opcode takes a number of T ...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…
... frequency - and handily enough, each opcode takes a number of T ...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…
... getOpcode = true) then counter = cycles(opcode)
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getOpcode = false
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decode opcode/byte (if no operands required ...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…
... of how long an instruction opcode takes to execute, in relation ... to point to the next opcode, which you fetch and decode ...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…
... Z80_pc
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Decide which opcode this is
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Get ... for each
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Do Opcode stuff
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Increment TStates ... by X (depends on opcode)
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Return
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…
... byte opcodes. Obviously, if each opcode was only 1 byte long ... has received is the entire opcode or if it is just ... easy, once you know the opcode).
MadDoc,
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…
... , they mean "get the next opcode and look *that* up in ...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…
Considering that you now have a ROM, you'll need to start emulating some opcodes.
For extra bonus points, can you tell me what opcode 243 is, and what it does?
D.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…
... am trying to emulate the opcode INC BC. Now I know ...Techy Z80 questions****** Question 1 ****** Take the instruction SET b, (HL). This is broken down (in machine cycles) as follows (according to Microprocessor Technolo…
... does the Z80 read the opcode that would have followed the ...
