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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…
... able to tell how may T-states are contended by counting the ... cycles. This doesn't tell us which T states were contended and by ... much, nor how many contended T states there are. Then we can ... the first and last contended T states, by running the instruction at ... -
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…
... This doesn't tell us which T states were contended ... nor how many contended T states there are. Then we ... first and last contended T states, by running the instruction ... what happens for the states in between.[/QUOTE]
T-states of the IO part ... -
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…
... QUOTE=csmith;213979]I don't know. I've always wanted ... , I talk about which T states of the IO/instruction are ... , I think we don't need to discuss this anymore ... you said, luckily it doesn't matter).
Edit: ... . No doubt you couldn't get what I was trying ... -
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…
... also explain why it doesn't apply it during T3 and ... low at start of those T states (thus the snow effect) as ... -
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…
... also explain why it doesn't apply it during T3 and ... low at start of those T states (thus the snow effect) as ... byte fetches because there won't be time for the instruction ... wonder if the timing isn't too sensitive.
If ... -
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…
... least point out explicitly which T-states of the memory read/write ... -
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…
... contention during the following two T states, but this extending is what ... I haven't got from the schematics (yes ... -
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…
... least point out explicitly which T-states of the memory read/ ... and 128k, the only instruction T states which are not contended are ... and M3 cycles, all other T states are not contended (the ... case of any extra inserted T states the contention happens according to ... -
Can you write in the border?Is it at all technically possible in any way to get stuff into the border, apart from changing the border colour? I believe the C64 used the border a…
... , which take 11 and 12 T-states respectively. In the upper border ... pixels) is painted in 4 T-states, and on a regular Spectrum ... a one-off; you couldn't do that repeatedly to build ... a complete picture). I don't think anyone's ever attempted ... -
ULA RAS, CAS cycles, refresh and "snow effect"Hello everyone. I have a question, does anyone observed timings of RAS and CAS generated from ULA? I think there may be answer to where the "snow ef…
The direct bus or indirect one... that is the questionThe Ethernet project continues...and I'm in a quandry. So I've managed to implement enough socket library for the W5100 that socket, bind, listen, a…
... is that the chip won't need to be memory mapped ... take the same number of T-states as LDIR.
[/QUOTE]
The direct bus or indirect one... that is the questionThe Ethernet project continues...and I'm in a quandry. So I've managed to implement enough socket library for the W5100 that socket, bind, listen, a…
... reference code. Which doesn't actually use auto increment ... incremented when it shouldn't - but only during reads ... is many many more T-states than an INIR instruction!< ... in less than 50 T-states on average - at ... eat up 30-odd T-states including the c register ...Problem with replacing all upper memory with 4164 chipsGuys, i have a problem with the high memory of a 4B issue. At first the board had OKI chips for high memory and one of them was faulty. Since its ea…
... Z80 goes low for one T-state (the falling edge of ... full memory write is 3 T-states) which will be 285ns. /RD ... goes active for longer (2 T-states), but the actual important time ... , which is probably only 1 T-state. (Someone who's familiar ...another c64 vs. Speccy site...[url]http://c64vsspectrum.com/[/url] 25 years and we are still brawling.. ;)
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There's 224 T-states per scanline, so by the ... calculation, something like 7 T-states per 8 pixel long memory ... have less that 1 T-state per memory read ... used, the CPU wouldn't be able to access lower ... takes 3 T-states, and there wouldn't be 1 T-state to ...Detecting a Kempton joystick...I've been playing with the idea in the games I'm currently developing so that once the Kempston joystick has been selected you can hold FIRE down to …
... my stuff, unless you can't enable ints for some reason ... screen/attr bytes.
; (~14k t-states on 48k). Normal Spectrum ROM ...Bizarre stuff in Interface 1's shadow ROMAccording to the Complete Shadow ROM disassembly, the function that exits back to the BASIC interpreter after interpreting IF1 commands is this: [co…
... I missing? I just can't see any point however hard ... instruction. It just wastes 7 T-states as far as I can ...Bizarre stuff in Interface 1's shadow ROMAccording to the Complete Shadow ROM disassembly, the function that exits back to the BASIC interpreter after interpreting IF1 commands is this: [co…
... =Winston;250720] I just can't see any point however hard ... instruction. It just wastes 7 T-states as far as I can ... the solution, i don;t think 7 t-states would concern the authors ... ...afterall it isn't time dependantEmulators 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…
... * crap. As the VIC doesn't have SID sound and sprites ... /> ...which takes a horrible 38 T-states, but I have freed up ...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…
... /> ...which takes a horrible 38 T-states, but I have freed up ... maincommands are reached in 26T states.
(my first emulator reached ... every code in 52T states)
After executing a ...How many expansions can a Speccy handle ?How many expansions / interfaces / addons can a Speccy handle ? I'm not thinking about the issue of powering the interfaces through the Speccy's PS…
... takes the same number of T-states regardless of the number of ... , the Spectrum's design doesn't allow for more without a ...Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
... for faster indexing. And don't use the index registers. Ever ... two versions take the same T-States.
I am using ... />
I will do a T-State count to see if ...Disappearing/appearing effectI remember doing a small routine in BASIC which could be used to cover the attributes section randomly, until all 704 characters were filled with the…
[QUOTE=BloodBaz;259453]I think the man (Woody) is right, the two versions take the same T-States.
[/QUOTE]
OMG! frobush is [i]wrong[/i]? He did post on April Fool's day so maybe he was just having us on... :wink:A BASIC compiler projectHi, I started my own BASIC compiler for the ZX Spectrum (and Z80 machines) 3 months ago. It's still in ALPHA stage (when it is mature, I will write …
... faster than C (you don't need to use CPIR), and ... parameters and local variables (don't know how Z88DK handles this ... delays it only 10 cycles (T-states) due to the Jump used ...Multiplayer online Speccy gaming - an actual technical proposalAs is so often the way, [url=http://www.worldofspectrum.org/forums/showpost.php?p=274215&postcount=121]trying to put into words why something is impo…
... clients know how far (instructions/t-states?) to execute within a frame ...Multiplayer online Speccy gaming - an actual technical proposalAs is so often the way, [url=http://www.worldofspectrum.org/forums/showpost.php?p=274215&postcount=121]trying to put into words why something is impo…
... be an absolute count of t-states executed since the server said ... in practice, but I don't see the difficulty either way ... an IN it executed 150000 t-states ago, it just needs to ... that point and execute 150000 t-states worth of instructions (which may ...InterruptsI need help emulating interrupts. My z80 core currently emulates all un-prefixed opcodes and the CB opcodes. I thought I would start on emulating co…
... for an interrupt every 69888 T states. Is this the largest common ...InterruptsI need help emulating interrupts. My z80 core currently emulates all un-prefixed opcodes and the CB opcodes. I thought I would start on emulating co…
... interrupts as well? I don't know if these are IM2 ... for an interrupt every 69888 T states. Is this the largest common ... screen draw cycle every 69888 T states. This number is different for ...InterruptsI need help emulating interrupts. My z80 core currently emulates all un-prefixed opcodes and the CB opcodes. I thought I would start on emulating co…
... for an interrupt every 69888 T states. Is this the largest common ... completely differently, so there isn't much point worrying about that ... T-state figure which is Spectrum ...CSSCGC 2008 has now officially begunFor coming last in the 2007 crap game compo, I have the honour and privilege of hosting CSSCGC 2008! I have now put up the CSSCGC 2008 website at …
... /> The 47 T-states opcoderoutine can be reduced to 26 T-states (same as ...
