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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…
... address 38, which has the opcode RST 38H, thus making it ... -
There's a bug in my Speccy, Dear Liza, Dear Liza...Hi guys, Just me being annoying again - Can anyone out there in 'Internetland' help me with ideas about what could be causing a bug in my Speccy em…
... at least compare how your opcode handlers work as opposed to ... -
There's a bug in my Speccy, Dear Liza, Dear Liza...Hi guys, Just me being annoying again - Can anyone out there in 'Internetland' help me with ideas about what could be causing a bug in my Speccy em…
... test for every single Z80 opcode, with the correct[1] output ... -
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…
... +d),B used for this opcode. Probably best for you to ... -
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…
... hold the result of the opcode.
000 - b
001 ... -
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…
... understand the exact way this opcode works.
According to ... -
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…
... should have done brute force opcode lookups rather than trying to ... -
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 ... must be an 8 tstate opcode, not two 4 tstate opcodes ... -
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 ... which to form the extended opcode; processing continues without interrupts;
opcode as if the DD didn ... -
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…
... this effect the DD-prefix opcode decoding logic? If the op ... -
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…
... this effect the DD-prefix opcode decoding logic? If the op ... -
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…
... the DD ED forms an opcode on its own, we'll ... -
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 ... -
The SPIN AssemblerI am using the assembler in Spin but I am having a problem with "DEFS". I was hoping that it would allocate a section of memory but it doesn't seem t…
... . It says 'invalid combination of opcode and operands'. The other listing ... />
I've had this opcode/operand thing happen with perfectly ... -
Fastest way to write something to screen$Hi, I just got pasmo.exe and start playing with attr scrolling, well, not scrolling, just write different values to a block and see if I can introdu…
How many T-states takes PUSH DE ?Hi. Just a quick one. According to z80.info docs, a PUSH DE should take 11 T-States to be executed. But WHAT if SP is pointing to Contended Memory,…
... to contented memory, so, the opcode is read from normal memory ...How many T-states takes PUSH DE ?Hi. Just a quick one. According to z80.info docs, a PUSH DE should take 11 T-States to be executed. But WHAT if SP is pointing to Contended Memory,…
... />
5 states for reading opcode of instruction
(if Programm ..."Sinclair Zx Spectrum: Absolutely Better Than Commodore 64"Did you ever read this? [url="http://www.alfonsomartone.itb.it/fztsmo.html"]http://www.alfonsomartone.itb.it/fztsmo.html[/url]
... 12 clock cycles for an opcode, the 6502 usually spends 2 ..."Sinclair Zx Spectrum: Absolutely Better Than Commodore 64"Did you ever read this? [url="http://www.alfonsomartone.itb.it/fztsmo.html"]http://www.alfonsomartone.itb.it/fztsmo.html[/url]
... 's 6510 (factoring in the opcode speeds and so forth) but ..."Sinclair Zx Spectrum: Absolutely Better Than Commodore 64"Did you ever read this? [url="http://www.alfonsomartone.itb.it/fztsmo.html"]http://www.alfonsomartone.itb.it/fztsmo.html[/url]
... you take the differences in opcode execution times into account) and ..."Sinclair Zx Spectrum: Absolutely Better Than Commodore 64"Did you ever read this? [url="http://www.alfonsomartone.itb.it/fztsmo.html"]http://www.alfonsomartone.itb.it/fztsmo.html[/url]
... just looked up a z80 opcode timing list and was amazed ..."Sinclair Zx Spectrum: Absolutely Better Than Commodore 64"Did you ever read this? [url="http://www.alfonsomartone.itb.it/fztsmo.html"]http://www.alfonsomartone.itb.it/fztsmo.html[/url]
... difference in clockspeed. The lengthy opcode timings on z80 would surely ... the gap a little. Longest opcode on 6502 is 7 cycles ...Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
... the Z80 receives an illegal opcode, ie. not an undocumented one ...Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
... " opcodes. A DD or FD opcode on an instruction not involving ...Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
... the machine with an illegal opcode. Modern processors have traps to ...Z80 QuestionCan the instruction EX DE,HL be prefixed with DD to give EX DE,IX? Derek
... .z80.info[/url] for an opcode map that includes all the ... site -- it contains a useful opcode map that shows which undocumented ...
