... happy with a 3.3v clock signal, since the CPU is TTL ...

... happy with a 3.3v clock signal, since the CPU is TTL ... was bugging me. the cpu clock is driven by a transistor ... anyway, so the clock edges should have a short ...

... circuit, and for Nmos versions, clock signal can only be held (constant ... , this is indefinite (static, hold clock forever if you want). Also ... TTL levels, but drive strength, signal rise/fall times and such ...

... circuit, and for Nmos versions, clock signal can only be held (constant ... 've "hand clocked" NMOS Z80s (clock cycles lasting seconds) without problems ... its register values with the clock held? I'm very curious ...

... anything about registers, just clock signal input. Grab a Zilog ... "hand clocked" NMOS Z80s (clock cycles lasting seconds) without problems ... circuit just switches from one clock signal to another, and thus ... never keeps the clock signal at a logic level for ...

... say anything about registers, just clock signal input. Grab a Zilog supplied ... , and look for "clock pulse width (high)" and "clock pulse with (low ... CPU with a given minimum clock speed, it's because internal ...

... would indicate a memory / CPU / clock signal problem, the latter would indicate ...

... the Z80 getting a reliable clock signal, do the address lines look ...

... the Z80 getting a reliable clock signal, do the address lines look ...

... 's to do with the CLOCK signal not being connected to the ...

... 's to do with the CLOCK signal not being connected to the ... /> Big whoops indeed. The CLK signal is certainly there in the ...

... 's to do with the CLOCK signal not being connected to the ... serial number doesn't have clock signal in the edge connector :-O ... any track in the pad clock .

Bye

... ;380393]Feeding any external tape signal to the +2A circuitry seems ... datacorder circuitry normalises the tape signal before
passing it to ... drive the CPU with clock signal. The input clock of the ULA was ...

... the Z80's clock signal: see if there is *some* clock signal directly on ... Z80's clock input pin. Not ...

... drive the CPU with clock signal. The input clock of the ULA was ... try one thing. Take the clock signal and make a circuit to ... are lucky, only output pin clock of the ULA is broken ... that ULA dodn't give clock signal for AY-8912 and I ...

... try one thing. Take the clock signal and make a circuit to ... lucky, only output pin clock of the ULA is broken ... RAM and generates the video signal. But there was no ... video signal at all. So I ... in case the CPU had clock the computer would work.[ ...

If the diags board does nothing - you know for sure (so long as the diags board is not fried!) that the Z80 is not actually doing anything useful. I'd also check the clock signal first.

... /> I measure quite a nice clock signal on pin 6 of the ... that the CPU gets its clock perfectly... As I have had ... seem related to the video signal (which is ok).

... you are able check if clock signal is present at CPU then ... check this. At Pin 6 (Clock pin) you should be able ... caused by a high frequency signal with a amplitude of about ...

... you are able check if clock signal is present at CPU then ... check this. At Pin 6 (Clock pin) you should be able ... caused by a high frequency signal with a amplitude of about ...

... interfaces use their own clock generators. Now I've ... problem, because without single clock source, or at least ... without very close clock rates, the two AY ... possible to get the clock signal right from built-in ... a hack, because the signal is not available on ...

... all - it uses the (contended) clock signal on the edge connector, so ... interface should use its own clock.)

The various AY ... running on *nominally* the same clock speed (e.g. a 128 ...

... all - it uses the (contended) clock signal on the edge connector, so ... interface should use its own clock.)[/QUOTE]

So it ... contended RAM because the effective clock frequency will keep changing!

... (or scope) is available, check clock signal(s)
3) Compare symptoms ...

... done with it. A missing clock signal is too simple a problem ...

... by lower RAM).
[*]Check clock signals (video+Z80) - you need ... above image I'd suspect clock signal(s) are present.
[*]Upper ...

... /off switch (eg. for a clock signal, that does NOT work :grin ...

... a counter chip to the clock signal, and read the output after ...

... be other causes though - CPU clock signal gone (buffer transistor dead?), power ...

... transistor in the Z80's clock signal (TR3). ULA itself seems to ... be having [I]some[/I] clock signal, otherwise there wouldn't be ...