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Printing text using direct screen addressingHaving some problems printing using the FASE engine which is currently defeating me. Hoping to have someone clear out the bit of fog currently dwell…
... , because it certainly gets the high bit of the address from #5C01 ... -
Retro Virtual Machine is out!Fantastic emulator Retro Virtual Machine (@retrovm) is out today. It can emulates Amstrad/Sinclair models range. Give a try! http://www.retrovirt…
... suite and it failed the R register test and the IR contention ... -
Retro Virtual Machine is out!Fantastic emulator Retro Virtual Machine (@retrovm) is out today. It can emulates Amstrad/Sinclair models range. Give a try! http://www.retrovirt…
... suite and it failed the R register test and the IR contention ... -
Retro Virtual Machine is out!Fantastic emulator Retro Virtual Machine (@retrovm) is out today. It can emulates Amstrad/Sinclair models range. Give a try! http://www.retrovirt…
... suite and it failed the R register test and the IR contention ... -
Retro Virtual Machine is out!Fantastic emulator Retro Virtual Machine (@retrovm) is out today. It can emulates Amstrad/Sinclair models range. Give a try! http://www.retrovirt…
... suite and it failed the R register test and the IR contention ... implements a Zilog one, the r behaviour is not the same ... -
Retro Virtual Machine is out!Fantastic emulator Retro Virtual Machine (@retrovm) is out today. It can emulates Amstrad/Sinclair models range. Give a try! http://www.retrovirt…
... suite and it failed the R register test and the IR contention ... this. I pass now the R contention test but not the ... -
Two different versions of Bruce Lee?There's a possible MIA here, I think. I sat down at lunchtime to play a bit of Bruce Lee and discovered that the version I'd downloaded from WOS (th…
... some funky stuff with the R register, and the POKE above in ... -
Can someone run this test program on a real Spectrum 48K?I've knocked up a small test program just to satisfy my emulation OCD if someone with a real 48K Spectrum can spare a couple of minutes to run it.? …
... !", "Illegal interrupt response" or "Incorrect R register value". I'm kind of ... -
Can someone run this test program on a real Spectrum 48K?I've knocked up a small test program just to satisfy my emulation OCD if someone with a real 48K Spectrum can spare a couple of minutes to run it.? …
... !", "Illegal interrupt response" or "Incorrect R register value". I'm kind of ... -
Plot questionHi all Is there a way of detecting whether a plot position has been plotted, or whether it's still 'empty' ? In short, I need to know for a pro…
... interested in anything but the high bit of the byte return (say ... you're querying bit 5) then you also add ... of more processing testing the bit.
All that will ... -
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…
... good use of the index register high and low eg. INC IXH ... them, along with the alternate register set.
http://www ... -
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…
... the string or set the high bit of the last byte of ... -
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…
... the string or set the high bit of the last byte of ... -
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…
... the string or set the high bit of the last byte of ... -
IDE interface emulation request (yet another one) Simple, 8-bit IDE interface emulation for interface described here: [url="http://piters.tripod.com/zx.htm"]http://piters.tripod.com/zx.htm[/url] …
Simple, 8-bit IDE interface emulation for ... 48/128 compatible).
Data register : #2B
Parameter reg.: ... Start sector r.: #6F
Cylinder low : #AB
Cylinder high : #AF ... Is +3E uses 8-bit or 16-bit port addresses? What about ... -
Madness or inaccurate docs: RR r/RL r?According to the Z80 User's Manual, the instruction RR r/RL r should rotate the carry flag into bit 0 or bit 7 of the register in question (bit 0 or …
... RR r/RL r should rotate the carry flag into bit 0 or bit ... 7 of the register in question (bit 0 or bit ... -
Correct flag response to BIT n,(HL) etc.When running the test program suggested by Arjun (thanks again), all intructions are passing the flag tests except the BIT n,(HL), BIT n,(IX+dis) and…
... except the BIT n,(HL), BIT n,(IX+dis) and BIT n,(IY ... output), and it passes all BIT instruction tests (but fails RLD ... , have you implemented the internal register mentioned in Sean Young's ... updated after 16 bit additions, JR and LD r,(IX+d)?.
A clever method of using a single 8-bit register to be used for two things at a timeI don't know if this is the way the SAVE routine in the Spectrum works. Anyway, this is what I've learned today. I've been commented the disassembly…
... for a '1' bit or '0' bit within the byte that ... I didn't found a register that holds 8, and in ... answer is: a single 8-bit register (L) holds both the ... just before entering the "transfer bit" loop, the carry is ... left to transfer, the L register is not 0.
...AND,XOR,OR,BIT,RES,SET,CPL,NEG,RLC,RRC,SLA,SRL,RL, RR,SRA for BASICAs this was drifting away from the original INKEY$ thread I thought that I'd create a new one. So here's a routine to provide all of the above mentio…
... bit of a problem with BIT, as it only changes the Flags register ... , XOR=X, OR=O, BIT=B, RES=R, SET=S
defb "A","X","O","B","R","S"
OPCODES:defb ... 9;b,"=";USR 40021+VAL "R,a,b"
51 PRINT ...High Score Musical - an 8-bit rom comHello all, [b]High Score Musical[/b] is a project I'm currently working on, and we're planning to take it to Edinburgh this summer. It's a new (slig…
Hello all, [b]High Score Musical[/b] is a ... ]http://www.wefund.com/project/high-score-musical[/url]. Feel free ... /> We've also made a bit of a demo video...
Using R as a loop counterThis is just something silly I've found a while back. xD [b][How-to][/b] Setup your routine like this:[code] ld a,X ;see below ld r,a loop ;your …
... ,X ;see below
ld r,a
loop
... from the final 'ld a,r: jr nz,loop' commands) ... br /> and #7F
ld r,a
.l2
nop ... inc b
ld a,r
jr nz,.l2
bit register, yay!
So ...Exact emulation of the Snow effectAs the original post on another forum is outdated, and for those who don't know about that forum, I duplicate this info here: At the beginning of …
... 6..0 of the register R are picked up in ... register I contains a value that, if it taken by the high ... pixels1/attributes1 addresses the bit 6..0 of address ... the bits 6..0 of register R (it should already be ... with a question of register R's participation in the ...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…
... copied from the high byte of a 16-bit storage register in the ... the addition
LD r,(IX/IY+d): takes the ... the jump
LD r,r': no effect
The ...InterruptsCan someone help with providing some info or a link about IM 2. I know I need to create a vector table and want to store this as high in memory as po…
... is combined with the I register (I in top 8 bits ... bits) to form a 16 bit address. This address is supposed ... want to store this as high in memory as possible to ... z80 puts IR (I reg, R reg) on the address bus ...8-bit or 16-bit registers?I'm playing around with writing a Speccy emulator for mobile Java at the moment. I did a quick and dirty port of Qaop, which does run but at less tha…
... to BloodBaz: ideally all register access would be done ... the overhead is too high for such underpowered devices ... stored natively as an 8 bit number)
4) ... bit whilst others (A, F, I, R) should be stored as 8 bit ... should either be 16 bit or "whatever you choose ...Goldfinch - an open software stack for mass storageYep, another pet project of mine to compete with all the others I've started. But hey, if I didn't get distracted by things like this I'd just get di…
...
The startup code (the bit of code that runs prior ... = fopen("d>1:hexdump","r");
/* Read block ... finite set of messages (a register containing message id which should ... br />
printf() through the high level FILE* returned by fdopen ...designing a computerHi everyone! I am designing a 4 bit computer and i need some advice, is this a good instruction set? [CODE] BINARY OPCODE DESCRIPTION 00000 nop…
... of deciding "if low or high nibble has the instruction in ... instruction positions. e.g. INC r instrucitons (7 of them work ... -bit instruction is 00rrr100b where rrr is 000 to specify which register ... then AND C (AND register C with register A) will become 00110 ...designing a computerHi everyone! I am designing a 4 bit computer and i need some advice, is this a good instruction set? [CODE] BINARY OPCODE DESCRIPTION 00000 nop…
... program?
2) What high level languages have you used ... increment). To clear a register you subtract or XOR it ... 16 BIT values to be loaded into the A register in ... out the 'LD A,R' instruction. Then came the ... got solved with the modulo register (MR). I've ...
