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Faulty M1 pin on a Z80 made from SGS?It's the second time I have come across this: a Spectrum that seems to work ok, but if I attach an Interface 1 or a DivIDE to it, it behaves as is no…
... Interface 1 and DivIDE use M1 signal as input (among others, of ... looked at the M1 signal using a scope, the signal is permanently low ... , didn't SGS implement the M1 pin on their Z80's ... -
Anatomy of a bad M1No, not the motorway (although at times the tarmac M1 goes about as well as this one...) But the bad M1 problem that seems to occur most with issue …
... /M1-dc-coupled.png[/img]
The signal ... closer to 0v than 5v (the M1 line is ... (probably including any other signal that runs nearby, hence ... connecting a Spectranet, the signal gets pulled up (there' ... s left of the M1 signal is a bit lower ... -
plus3e simple ide interface problemhi, I prepared a 8bit simple ide interface 3 days ago, but I got problems (with or without ide cable connected). 1.First of all, I have to press re…
... the symptoms of a broken m1?[/QUOTE]
... normal I/O) also M1 goes high (say 5V). ... access ), then the
M1 signal shows no activity.
... /> experiment without using M1 in the address decoding.
weak ULA's.
- ... -
Spectrum 8bit IDE adaptersHello there my fellow WoS'ers Today I am pleased to (finally) release these little adapters into the wilde [URL="http://postimage.org/image/1aceto6…
... br />
[B]Bad (weak) M1 signal (pin 27 of Z80)[/B ... may have a bad (weak) M1 line - this is quite ... CPU with a poor M1 signal... I went onto ebay ... CPU with a bad/weak M1 line wont work with ... [/INDENT]
[B]Signal Strengths & Cable Lengths[/B ... -
divide question - ribbon cable?Hi - recently got a divide and loving it but not enough room on my desk. Is anyone aware of a supplier of a ribbon cable that could sit between +3 …
... introduce wire you also introduce signal doplar (reflection), interference as well ... as signal pickup, even at 3.5Mhz ... weak signal strengths - especially noted is the M1 signal from the CPU, if this signal ... -
Which type of Z80 cpu to use with ZX 48?Which type of Z80 cpu can I use with ZX 48? Only the 4 MHz cpu's or some with more MHz? Did not know if a 6 MHz cpu runs in a ZX 48 with 4 MHz. Mic…
... showed issues like a Bad /!M1 signal or weak signals over all. I ... -
Issue 4S bad M1Never ever seen a 4S with a bad M1 line before today [url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img…
I think Macc means the Z80 itself. Some of them apparently have a weak M1 signal which causes problems with some hardware (DivIDE for example) -
Microdrive faultHi, After a chat with "Winston" at the R3PLAY show I have been able to fix my 48k spectrum faulty M1 signal. My problem with the microdrive is int…
... fix my 48k spectrum faulty M1 signal.
My problem with ... -
Fully-addressed devices initiative (FADI)I would like to introduce an initiative for those who create new pieces of hardware containing legacy devices with well-known addresses. It says that…
... or 16 addressing bits and /M1 signal should be decoded. For example ... detect A0 to A7 and /M1 signals (and /IORQ, of course ... to A15, and /IORQ and /M1 signals.
I call ... -
harvard architecture spectrum clone.I got my first +2 before christmas. I'd never given the 128k spectrums much thought, always been a 48k rubber key tradionalist. :smile: I've been me…
... in with a read and M1 signal plus other logic for some ... but not classed as a M1 cycle, (need to look in ... and reads that are not M1 cycles. display file would be ... -
Power Play Joystick InterfacePower Play Joystick Interface for the ZX Spectrum. This is a Kempston compatible interface. Address decoding Any IO address where A5 is low... …
... as a read...
The /M1 signal is also proved and needs ... -
divIDE issuesI discovered a few issues with the divIDE hardware and FATware software that may be of interest to some people. 1. ROM paging If your Spectrum is a…
... achieved by forcing DivIDE's /M1 input to 1 (using OR ... , or 470-ohm-resistor-weaken /M1 signal tied to +5V directly etc ... -
divIDE issuesI discovered a few issues with the divIDE hardware and FATware software that may be of interest to some people. 1. ROM paging If your Spectrum is a…
Hello.
Such things like paging inhibition must be done internally in all the non-standard machines. I suppose that in the area #0000h-#3fffh is always the vanilla 48k ROM (and for 128k / +3 clones the firmware outs #1ffdh -
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.
InterfaceHi I'm building a spectrum emulator. I've tried to build it as modular as possible, for example I have a zx class that have input and output devices…
You will probably need to emulate the Z80s M1 signal as it is used by the interfaces to determine whether the memory address is being read as data or as a commandMULTITECH pictures[url]http://velesoft.speccy.cz/data-gear.htm[/url]
... the Reset-Button and the /M1 signal of CPU. Only the combination ... button and rising edge of /M1 trigger the Reset function. I ...DivIDE+ and 128K HeatsinkI got my DivIDE+ yesterday and i tried it on a 48K+ at first, it worked marvelously on it, no problems at all. Today i desided to try it on my 128 H…
... don't believe in the "M1 fault". I also had problems ... indeed had to do with M1. In one case I had ... simple way of making inverted M1 signal using a transistor (don't ...Problem with Discovery OpusI've just got a Discovery Opus, but it seems to be faulty. When I connect the Speccy and switch it on, it displays the "C 1982 Sinclair Research", …
I would re-check M1 line. You said that an ... in the path of the M1 signal from the bus connector.Dead DivIDE?I just switched on my 48K for the first time in ages (which still works fine thankfully) but when I tried it with my DivIDE+, it repeatedly crashed. …
... DivIDE is probably the accursed M1 fault. Many peripherals won't ... CPU has a faulty M1, because the M1 signal is needed so the ...Opus DiscoveryI've got an opus dicovery 1 with 2 x 3 1/2" drives. I used it many times on my 48k but it doesn't work with my 128k toastrack. It also had some sort …
... your computer has a faulty M1 signal (not uncommon).Spectrum+ from ebayI recently received a Spectrum+ that I bought off ebay for about ?10 including postage. I have not tested it yet but had a quick look inside through …
... CPUs did not generate the M1 signal correct. In that case also ...RFC: ZXI hardware interface standardisationReposted from c.s.s to reach a wider audience [QUOTE=Andrew Owen] You may have noticed that there are more people making add-ons for the Speccy than…
... straight connection from the INT signal at the rear bus, to ... device to use the INT signal? If it's the case ... into account the M1 signal and/or the RFSH signal, so misdecondings won ... ) can be ZXI compliant? The signal is documented to be on ...Microdrive faultHi, After a chat with "Winston" at the R3PLAY show I have been able to fix my 48k spectrum faulty M1 signal. My problem with the microdrive is int…
... fix my 48k spectrum faulty M1 signal.
My problem with ...Faulty Interface 1I bought a 'tested' Interface 1 on ebay the other day. Aside from the previous owner 'cleaning' the contacts with WD40!!! (bad, bad, bad eeurrgh :rol…
... with faulty Z80 CPU ( bad M1 signal ) and as such the Speecy ...Spectranet updateOK, so I've not written an update here for a while...so here's a quick summary, the gory details are on the Spectranet news page on my wiki. * Hardw…
... IF1 because of a Faulty M1 signal.
I researched this ...Hacking a Joystick InterfaceI have a DK'Tronics twin-port joystick interface that does Kempston and Sinclair 0-6 keys. I know it has only 14 lines connecting it to the edge con…
... for being completely safe the /M1 signal should also have been brought ... by DKTronics, preventing action when /M1 is low. Don't know ...Known Z80 M1 problems?I got an email yesterday from someone asking for a Z80 without the M1 problem. I only know about the fanout problem that many Z80's are suffering of…
... to know is if the M1 problem is the same as ... not suffer from a bad M1 line or bad fanout.
M1 signal by adding a transistor to ...Known Z80 M1 problems?I got an email yesterday from someone asking for a Z80 without the M1 problem. I only know about the fanout problem that many Z80's are suffering of…
@beverstee
Sadly as Winston points out... some Z80's don't even have enough of an M1 signal to amplify with a transistor.Known Z80 M1 problems?I got an email yesterday from someone asking for a Z80 without the M1 problem. I only know about the fanout problem that many Z80's are suffering of…
... possible to solve the bad M1 signal by adding a transistor to ... boost the signal?[/QUOTE]
Not if ... do it, but the bad M1 lines I've seen don ...
