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PlusDlite problems with 128K modelsLast year I developed the PlusDlite, and already shipped out a couple of them. Only recently I discovered some problems with 128K models. I remember…
... 005E POP AF Restore A register and return to the
0062 PUSH AF Save R register and interrupt status.
... NMI PUSH AF Save A register.
0067 JR #0053 ... -
Does this addressing technique have a name?Hi All, Bit of a weird/unnecessary question, but can anyone help build on my knowledge of asm terminology by telling me what the *second* method of …
... ] extended addressing
r register addressing
[rr] register indirect addressing
[/code ... -
Sorting BusinessThis is a little bit different from the usual game-related fare but I know there are a few people here who like this sort of thing. This is about so…
... tried the median of L/R/MIDDLE pivot selection and including ... of the growing L or R side partitions or not. Hopefully ... . I'll be using the R register for a quick random decision ... I can figure out which R bits to look at to ... -
Sorting BusinessThis is a little bit different from the usual game-related fare but I know there are a few people here who like this sort of thing. This is about so…
... to the exchange set. The R register is there, but I'll ... -
HALT: Why always 4ts?Instruction breakdown of halt is like that: PC 4ts. That means it fetches instruction byte from ram which tooks 4 ts and then does nothing and read…
... .[/QUOTE]
Sounds logical. So R register keeps being updated, too. And ... when HALT is exit-ed, R value may say something about ... -
TV Pal, odd and even framesI have been researching, but haven't found any real interesting information on this subject, so far. What I mean is, since TV PAL signal is interl…
Maybe the count in R register is different after a few cycles after Interrupt, between odd and even pages, since ULA stops the CPU clock in some situations (accessing screen memory is probably one of them), and odd and even lines have different timings. -
Spectrum +2A floating bus portHi As I discovered in the past, Spectrum +2A (and probably +3) do have floating bus port. But it is not shown on all unused ports, only on some po…
Bored of the Rings coded messageI was browsing [url="https://tcrf.net/"]The Cutting Room Floor[/url] recently and stumbled upon the entry for [url="https://tcrf.net/Bored_of_the_Rin…
You may need to know the value of the R register at the time the message was created :-)Bored of the Rings coded messageI was browsing [url="https://tcrf.net/"]The Cutting Room Floor[/url] recently and stumbled upon the entry for [url="https://tcrf.net/Bored_of_the_Rin…
... know the value of the R register at the time the message ... the message was "encrypted" using R register, it would be impossible to ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... LD I,A and LD R,A, associated with (A15, A14 ... we know that I and R register are both reset to ZERO ... is constantly outputting I and R values on the bus, so ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... we can control I and R register, it's possible to force ... the I and R register to become ZERO.
The R register is incremented ... A,(#0000) -=> I = 0, R = 0, Address = #0000
< ... doesn't change, even after R register increment/overflow, which can be ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... sets a specific value for R register, that will be checked on ... uncommon to happen, since changing R register might wrack your memory refresh ... and crash ZX. So this register is usually untouched. (still have ... sets it to)
Current R value can also be saved ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... support & correctness of the R register behaviour.
... br /> [quote]Memory Refresh (R) Register.
The Z80 CPU ... /> NOTE: Reset also sets R register to zero, hence also changes ... any instruction fetch. Hence R register can be considered a ...R registerI'm cross-posting this as a spin-off of a [url="http://www.worldofspectrum.org/forums/discussion/52748/zx-spectrum-cartridges/p2"]thread in "Hardware…
... br />
6.1 R register and memory refresh
[ ... issued. The whole IR register is put on the ... the Z80 increases the R register before or after putting ... without a prefix increase R by one[/u]. [ ... LD A,R and LD R,A access the R register after it ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... .worldofspectrum.org/forums/discussion/52782/r-register"]this dedicated thread[/url].
R by one[/u]. [b] ... CB, DD, FD prefix, increase R by two, and so do ... . LD A,R and LD R,A access the R register after it is ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... uncommon to happen, since changing R register might wrack your memory refresh ... and crash ZX. So this register is usually untouched. (still ... it to)
Current R value can also be saved ... on the behaviour of the R register (including knowing that you can ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... #00, and toggling bit 7, R register in sequence.
I ...ZX Spectrum CartridgesI have been thinking of "cloning" ZX Cartridges for a while (case, board and silicon skirt), to be able to make new releases or replace damaged cartr…
... address, by controlling I and R register.
P.S ...So where is the random number in the Speccy ?So I am messing around with ZX Spectrum Assembler and I want a random number. I looked up previous posts and one of the links said that random number…
... is probably to load the R register or the LSB of FRAMES ...Graphics program in AssemblyHi so I think I'm getting the hang of this so I've done this program. It writes directly to the screen. I'm using ZX Spin. [code] LD HL,16384 LD B,…
... ="ivanb303;885498"]What is the r register?[/quote]
Basically, its a ... most-significant bit never changes) register that's incremented every machine ... "]Z80 Technical Information about the R register[/url]Spectrum 48+ 4S - Upper RAM issue, and now a self-created problem!I recently picked up a known-flaky spectrum off eBay, to have a bit of fun fixing it and reliving youth. It was labelled as 'keyboard duff, shows…
... outputs the contents of the R register and the I registers to ... . R feeds A0 to A7, the contents of the I register goes ... the value held in the R register, except for bit 7, which ...In-game AY music and sound effectsI'm currently working on various aspects of a Spectrum game and thinking now about the sound side of things. I know you can use a utility like Vortex…
... the high bit of the r register to indicate when an interrupt ...The I register pointing to $40–$7f causes ULA snow and a crash. Or does it?I have heard it from numerous sources, including a few members of this forum, that 128K/+2 machines crash if the I register points to a range of $40–…
... ISR itself simply reads the R register, places its value into A ... mucks about with the I register but restores it prior to ... just by setting the interrupt register to $40–7f but to ...A snapshot to transfer converterI'm programming a tool that takes an snapshot file and convert it to a tape file that mimics those created with transfers. This is a long term projec…
... .
- Have some doubts about R register. I've got to test ...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 ...
