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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…
... so there are odd and even frames, which means it ... processing all lines (odd and even) on every frame (PAL ... in one color and even lines in the other.< ... out which frame (odd or even) the ULA is currently ... current frame is odd or even.
maybe trying to ... -
Bizarre ZX Spectrum faults (also possibly relevant to Spectranet compatibility problems).I'm attempting to repair an issue 4A 48K ZX Spectrum and am encountering some very strange problems. For my own records I've given this computer the …
... Z80 had a non-functioning /M1 output (this is very ... CMOS Z80 and confirmed its /M1 output works correctly. ZX285 would ... noticed something odd. Without me even touching the keyboard membrane, Miner ... but one with a working /M1 output. The Spectranet interface now ... -
Faulty M1 or no?Hi all, OK, so I've got an issue 4B which was pretty much untouched and appears to work fine (starts up OK, loads games, 23732 and 23733 both retu…
... I thought, "aha! a dodgy M1 line", so I removed the ... -
He's back! Not sure why, or even if anyone will remember him, but he's back anyway.Yes, *he* is back. Unless you're British, over forty, and haven't gone senile, then you probably won't remember him, but he's back, nonetheless. T…
... barely remember the cartoon, and even if it is/was true ... live action film?
Even if the film companies are ... -
Getting an even random numberWhat would be the best, simplest way to do this ? I was thinking of say: A = RND*100 Then a conditional along the lines of: IF A / 2 <> I…
... ) then it must be an even number not an odd number ... it must always be an even number. -
Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![quote]Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![/quote] Err, why? If you are trying to use an interfa…
[quote]Of course, when the M1 line of the Z80 CPU ... Z80 MPU with a working /M1 line, yes of course.
M1 line. So it’s irrelevant ... -
InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... V flag is reset, even if interrupts were enabled beforehand ... 0x0038:
* M1: 7 tstates: acknowledge the interrupt ... routine:
* M1: 7 tstates: acknowledge interrupt and ... cycles:
* M1: 6 tstates: acknowledge interrupt.
PokesDoes anyone know where I can find a list of Pokes for my Speccy games? I am trying to find some for On the Bench ! Thanks
... the last short part, "[B]M1[/B]") you -[I]can[/ ... ] into the game thereafter, even after the final little part ... the final loader part ("[B]M1[/B]") deletes. You'll ... you could [B]LOAD "M1"[/B] and [B]LIST[/B ... completely remove the [B]MERGE "M1"[/B] from [I]line ...Sparky eZX-BASIC Project in need of FPGA ExpertYou probably are not familiar with this project, but it is a computer system based on Zilog's new eZ80 chip and the OS is a superset of ZX BASIC. Ju…
... is nothing like the Z80, even though it's 95% compatible ... /> There is no longer a M1 pin nor a WAIT pin ... inactive, as there's no M1 to tell you and there ...Dead Spectrum diagnosis and desolderingI have two dead Spectrums - one I'm pretty sure is caused by bad memory, and the other - well, perhaps a bad ROM, perhaps a bad CPU (it gets halfway …
... see lines like /RFSH and /M1 and the address lines are ... , try changing the 4164 block, even though it's un-selected ...toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... additionally - although my analogue electronics fu is not all that strong, looking at the schematics for an Issue 2 suggests that the power supply that generates some of the 'weird' voltages (+12v) is a switch mode power supply, which gets regulated by ...toasted soeccysHello, ive jsut bought a pair of speccys on ebay (one 16k issue 2 & a prob 48k issue 3) unfortunaly the genius who sold them tried to see if the wor…
... , looking for A0=high and M1=high when IORQ=low is ... via the parallel port. Or even just an octal flip-flop ...Faulty M1 linesI'm sure this has been discussed before, but using the forum search for the word 'M1' pulled back no hits, which surprised the hell out of me. Anywa…
... I think it's the M1 syndrome in one of my ... in the unmodified one. I even checked three different Z80 chips ...It's fitting...... that in the very month that the 25th anniversary of the Speccy falls on, I'm just finishing up making my first ever Spectrum peripheral. It's a …
... [B]MREQ[/B] or even from [B]M1[/B] lines.
There ...Faulty M1 linesI'm sure this has been discussed before, but using the forum search for the word 'M1' pulled back no hits, which surprised the hell out of me. Anywa…
... high. (IORQ low and M1 low = an interrupt acknowledge ... Speccy.
The M1 problem therefore appears to ... shouldn't I? (or even you!)
Doing this ... /> [quote=Winston;181349]The M1 line isn't actually needed ... don't!) with M1, while monitoring M1 and some other ...Testing RAM Chips After RemovalHi I am going to use Winstons Hot Air Gun method of removing the RAM chips from a 4S circuit board. I wish to check the RAM chips, I have a Logic Pr…
... 've found out about faulty M1 lines, I'm making a ... so that the use of M1 is selectable by jumper, so ... or non-dodgyness of the M1 signal can be determined.
even if you took out the ...Testing RAM Chips After RemovalHi I am going to use Winstons Hot Air Gun method of removing the RAM chips from a 4S circuit board. I wish to check the RAM chips, I have a Logic Pr…
... PCB layout for 'use M1 / don't use M1' to allow for ... to test the CPU's M1 line.
I've ... designed for easy home etching (even though it's two sided ...That is one ugly carBMW reckons this is their Merc killer [url]http://cars.uk.msn.com/News/car_news_article.aspx?cp-documentid=4718673[/url] Jesus Christ but that is o…
[QUOTE=aowen;184360]Even the M1?[/QUOTE]
Only if it has the badges removed.Spectrum Diagnostics Board - 25th Anniversary projectWell, I said I'd try and get something online about this by today, and I have indeed done so. This web page still needs finishing off (in particular,…
... - such as the CPU clock, M1 line, address and data bus ... so you get some output even if you can't get ...Interface 1 electrolytic capacitorsInterface 1 has three 47μF electrolytic capacitors. Is it necesary to replace them with fresh ones? I always do this with old speccys but is it…
... old. Why take the risk - even if minimal?
Indeed ... the Z80 with the dodgy M1 line - only a problem if ...Oxford Speccy meetup, October 20th[b]Update:[/b] Date and venue decided - The Gloucester Arms, from 2pm, 20 October 2007. Full details: [url]http://matt.west.co.tt/spectrum/oxford-spe…
... the massive signs on the M1 just outside London. Well, except ... the road itself wouldn't even be considered a B road ...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…
... T4 of [B]each[/B] M1 cycle. Why it doesn't ... to ~IOREQ at all. Not even as a product of something ...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…
... means that only T1 of M1 (op code fetch), M2 (memory ... states are the T1 of M1, M2 and M3 cycles, ... the PC in case of M1 cycle and according to the ... , IR pair in case of M1 cycle, and port address in ... bus value does not change even if the registers involved have ...A vexatious questionThis is kind of a follow-up to a question about RST #8 and hardware that I wrote in the development forum a while ago. To summarize that: certain ha…
... RST#8 is executed, or even a CALL/JP #8, the ... in [I]after[/I] the M1 cycle, where the CPU picks ...Input/Output on Edge ConnectorI would like to sense a pulse on the data bus via the edge connector, i.e. on or off. How do you decide what port it is on? I would also like to send…
... , 0 volts is logic 0. M1 is high (+5 volts).
even numbered port address). This means ... the right port address while M1 is high, IORQ is low ...Rom dumping a Mirage MicrodriverI need to dump the rom of my Mirage Microdriver for Zub and don't know what to do...any help?
... magnitude comparators) plus the M1 and MREQ line. M1 active + MREQ active ... well aware of that (having even produced a screenshot of it ...divIDE woesHi y'all ! Last night I built my lovely divIDE ;-) I downloaded flasher and +divide.tap from [url]http://www.biehold.nl/rudy/+divide/index.htm[/url…
I think the DivIDE page-in works on an instruction fetch for all entry points including reset, so if you have a bad M1 line it'll never page in, not even on boot (I think that's what it did when I plugged it into a Spectrum with a known bad M1 line).divIDE woesHi y'all ! Last night I built my lovely divIDE ;-) I downloaded flasher and +divide.tap from [url]http://www.biehold.nl/rudy/+divide/index.htm[/url…
... root cause of the bad M1 lines are - now seen with ... ? Both the machines with bad M1 lines that I've encountered ... the hell does a faulty /M1 line do? I guess choices ... IF1, the other does not even finds it's plugged in ...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…
... faster than through hole passives, even 0603 parts - no leads to ... executing (i.e. MREQ active + M1 active + RD active) at addresses ... . /RESET goes low) and MREQ + M1 at address 0x0000. Hold through ... bus and catch it before M1 goes low.
I ...
