Reliable source for NMOS Z80? Z0840004PSC really/alwways supports out(c),0?

[eto]

I just went through a couple of hours of bug tracking just to recognize  that my Z0840004PSC is not an NMOS CPU - or at least it does not behave like Arkos Tracker expects it (undocumented opcodes).

I could test 3 different Z0840004PSC CPUs, all from the same seller, and only one of them behaved correctly. The others produced white noise when I played back music with Arkos Tracker.

Basically I have two questions: Do we know for sure that all Z0840004PSC should be NMOS and should all behave identically? Or is there the possibility that they changed the  behaviour but not the name?



If they should behave identically: Can someone recommend a reliable source where I can be sure to get NMOS CPUs and not relabelled ones? The last batch I bought was from a seller (adeleparts) who was recommended here as being trustworthy, but obviously something went wrong...

[McArti0]

It would be better if someone started producing miniature hardware patches and forgot about power-hungry NMOS.

[pelrun]

Thanks for volunteering!

[eto]

additional question: Can I also use a Z80B CPU? Or is there any reason not to do it?

I found some Zilog Z8400BPS from a source in Europe (I already bought other ICs in the past from them) and they are cheaper than Z80A from China.

[Prodatron]

Maybe you remember this thread:

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/replacement-z80a-cpu/msg220201/#msg220201

It seems: Yes, you can.

[eto]

Maybe you remember this thread:

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/replacement-z80a-cpu/msg220201/#msg220201

It seems: Yes, you can.

Now I do...

there is actually also the link to the seller which was recommended - but at least 2 of the CPUs I bought from this seller behave differently than the NMOS Z80.

[McArti0]

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/zilog-z84c0020peg-in-my-cpc-not-all-works/msg242936/#msg242936

Eto you really wouldn't want to do something like that?

[Brocky]

what about the other z80 derivatives? the mostek, sharp or toshiba branded z80s?... 
im sure the mostek chips are identical internals so have the undocumented opcodes.. not sure about the others tho..

[Egg Master]

It would be better if someone started producing miniature hardware patches and forgot about power-hungry NMOS.

It seems to be the same for the CRTC. 200mA to 100mA depending on the circuit version.
Is it really a CPC power consumption issue now? And CTM vs LCD?

- PSC is "standard" temperature range (0°C to 70°C)
- PEC is "extended" temperature range (-40°C to 100°C)

- Z84xx is expected to be NMOS
- Z84Cxx is expected to be CMOS

If you would like to know if a Z84xx PSC/PEC is a real NMOS or a relabeled CMOS circuit, test its power consumption.
May be the Zilog "bug fix" was applied to the CPU design was already existing on the last produced NMOS circuits?

Anyway, can the Z80 really fail often, or is it just because the tests are focused on it?
Sometime, someone search for a problem for witch he has already found a solution.