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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…
... So I drilled out the M1 line on my test board, ... timing issue (although the M1 line would have to be ... instruction).
The M1 line isn't actually needed for ... Z80 has a faulty M1 line). I still want to ... scope probe on the M1 line to try and figure ... -
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…
... So I drilled out the M1 line on my test board, ... timing issue (although the M1 line would have to be ...
[quote=Winston;181349]The M1 line isn't actually needed for ... Z80 has a faulty M1 line). I still want to ... scope probe on the M1 line to try and figure ... -
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 ... on power up. The WR line on the flash chip is ... -
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 lines ... -
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…
... the Z80 with the dodgy M1 line - only a problem if you ... -
Printer InterfacesI have a customer who wants to connect an Epson 850 printer to a humble rubber key Speccy. Now I happen to have 3 printer interfaces (all Kempston) …
... standard Z80 (it's the M1 line I think), there's every ... -
Printer InterfacesI have a customer who wants to connect an Epson 850 printer to a humble rubber key Speccy. Now I happen to have 3 printer interfaces (all Kempston) …
... standard Z80 (it's the M1 line I think), there's every ... don't rely on the M1 line but monitor IORQ and WR ... only every active simultaneously when M1 would be active so you ... can get around the M1 not working problem that way ... -
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…
... not contended. This way, all M1, M2 and M3 can execute ... contention only if the MREQ line is active, whereas the 48K ... refers not to the regular M1, M2 and M3 cycles, but ... -
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…
... at start of T3 of M1 is low for very short ... the ULA must sample the line with the rising edge of ... goes high in T3 of M1. So I was wondering what ... -
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…
... hits 0x0008 (i.e. an M1 cycle with 0x0008 on the ... ' way of handling the ROMCS line so that two peripherals with ... -
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).
line decoder.
Here's ... the right port address while M1 is high, IORQ is low ... -
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…
Out of interest, is it actually necessary to decode the M1 line? Under what circumstances would IORQ go low when it wasn't a port access? -
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…
... special M1 cycle when the Z80 acknowledges the INT line, where ... IORQ goes low and M1 goes low ... 't pay attention to M1 then interrupt acknowledges can ... to use is IORQ+M1 since you need one ... you can test the M1 line by jumpering M1 (quite a few ... -
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…
... actually necessary to decode the M1 line? Under what circumstances would IORQ ... -
Interface rom - Need help to dump itHi, I have temporarily an interface that is similar to a multiface. It has an NMI button and displays a menu where states can be saved and pokes ent…
... the interface does decode the /M1 line from the Z80.
This line goes active (0 volt) whenever ... address' contents as data, so /M1 is inactive when accessing it ... -
Interface rom - Need help to dump itHi, I have temporarily an interface that is similar to a multiface. It has an NMI button and displays a menu where states can be saved and pokes ent…
Interface rom - Need help to dump itHi, I have temporarily an interface that is similar to a multiface. It has an NMI button and displays a menu where states can be saved and pokes ent…
... presumably doesn't monitor the M1 line). I extracted it by calling ...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?
... whether the IORQ line is wired, or the M1 line is wired or ...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?
... whether the IORQ line is wired, or the M1 line is wired or ...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?
... whether the IORQ line is wired, or the M1 line is wired or ...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…
... is 0, ROMACC=1, M1=0 and MREQ=0, ... guess it's an M1 problem as Winston suggested.< ... What happens if I hold M1 low I wonder?
... Update:
I disconnected the M1 line from the edge connector and ... on that.
Proves the M1 problem though. Hurrah!
...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 are ...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…
... a machine with a faulty M1 line, the address decoder either ... in this case only with M1 = high, IORQ = low, WR ... a machine with a dodgy M1 line fails to cause page- ... are expecting some address and M1 low, and fails to ... scope probe to the M1 line on a faulty one ...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…
... Kempston that decode the RD line, and thus won't be ... 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 ...Faulty M1 LineHello, I've got a new DivIDE but it's not working with my Spectrum 48k+. I've got a sneaking suspicion that it's a faulty M1 line. Is there any way …
... a machine with a bad M1 line, I keep meaning to put ... what the nature of faulty M1 lines are, to perhaps discover ...Faulty M1 LineHello, I've got a new DivIDE but it's not working with my Spectrum 48k+. I've got a sneaking suspicion that it's a faulty M1 line. Is there any way …
... out that had a bad M1 line. I installed one of those ...DivIDE HelpHi all, After a rather long wait my DivIDE from Papaya labs arrived. I connected it to my spectrum, turned it on and...nothing. The green power LED…
Have you tried another Spectrum?
I don't know which Spectrum issues contained a faulty M1 line. Issue 4 may have been one of them.
I assume you have tried with no IDE periphials attached.Faulty M1 LineHello, I've got a new DivIDE but it's not working with my Spectrum 48k+. I've got a sneaking suspicion that it's a faulty M1 line. Is there any way …
I had a speccy with an M1 faulty line, the Multiface128 didn't work, the machine reseted each time i pressed the multiface's red button.
Changed the Z80 and that fixed the problem.Faulty Spectrum (help requested)I have an issue 6a specci. It's Z80 has the fault m1 line problem (Multiface 128 does not work). So I decided to put in a new Z80 but unfortunately i…
... a functional connection from the M1 pin of the CPU to ... issue 6a board the RFSH line of the CPU is NOT ... any wires (neither RFSH nor M1)...
Thomas
