how to verify if a multiface 1 is working correct ??

jojo
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Joined: Mon Mar 16, 2020 5:25 pm

how to verify if a multiface 1 is working correct ??

Post by jojo »

Can some one tell me how to verify the working of a multi-face 1 please

i sorted out the connections , but apparently nothing works ( no menu on the screen after pressing the nmi button )
Last edited by jojo on Fri Apr 19, 2024 3:29 pm, edited 1 time in total.
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
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1024MAK
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Re: how to verify if a multiface 1 is working ??

Post by 1024MAK »

Is the /NMI signal getting to the Z80?

Is the multiface paging out the BASIC ROM and enabling it's own EPROM?

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

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jojo
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Re: how to verify if a multiface 1 is working ??

Post by jojo »

Hi , Mark ,


its definitely not its own rom , i see the standard logon screen on the speccy

should it replace the standard logon screen with the colorfull option screen ??
MF1.gif
MF1.gif (1.11 KiB) Viewed 1239 times
this screen is NOT visible !!


only speccy and right arrow from opus 2.31

m_IMG_5827.jpg


remember i am working on the butchered "thing" with the opus discovery in the pc-case

i already found the meaning of the 4 wires hanging out , it is J1 and the nmi switch ( j2 is left open ) , will investigate later this evening

is there a chance multiface and opus firmware clash with eachother ??
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
acsi
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Re: how to verify if a multiface 1 is working ??

Post by acsi »

should it replace the standard logon screen with the colorfull option screen ??
With the multiface the standard boot screen will be displayed and the menu screen should be displayed after you press the button.
jojo
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Joined: Mon Mar 16, 2020 5:25 pm

Re: how to verify if a multiface 1 is working ??

Post by jojo »

mmm , not working at all .

closed J2 to enable the multiface , J1 left open to disable the kempston .
but after clicking the button speccy reboots .

so no colorfull screen visible .
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
jojo
Posts: 137
Joined: Mon Mar 16, 2020 5:25 pm

Re: how to verify if a multiface 1 is working ??

Post by jojo »

@1024mak ,

pressing nmi results in a speccy reset .

hope you can give me some hints .

all ttl logic has been tested and is ok .

eprom has already been changed for a new one , same result .
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
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1024MAK
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Re: how to verify if a multiface 1 is working ??

Post by 1024MAK »

Either by design or by mistake, the NMI handler in the BASIC ROM will result in the Z80 jumping to the reset vector. With a MF1, it should switch out the BASIC ROM (forcing /ROMCS high) and page in its own ROM. Hence during the NMI it's the MF1 ROM that should be in control.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
jojo
Posts: 137
Joined: Mon Mar 16, 2020 5:25 pm

Re: how to verify if a multiface 1 is working ??

Post by jojo »

it will keep the speccy's rom , not switching to mf1 .

i am a bit out of options i fear .

And as some mooro..... has soldered everything together it is almost impossible to remove the mf1 board ( without damaging it ) .

might the ram be a possible deal-breaker here ?
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
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1024MAK
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Re: how to verify if a multiface 1 is working ??

Post by 1024MAK »

I'm guessing, but I would have thought that if the RAM was faulty, you would get different symptons.

Is it really permanently soldered to the Speccy :shock: That makes it awkward...

Have you checked for solder splashes and short circuits? Also open circuit / bad connection issues?

This site has some technical details that may help.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
jojo
Posts: 137
Joined: Mon Mar 16, 2020 5:25 pm

Re: how to verify if a multiface 1 is working ??

Post by jojo »

some pictures of the disaster area ;
m_IMG_5938.jpg
m_IMG_5939.jpg
m_IMG_5940.jpg
everything soldered together , no history known .

2 problems ,

no working multi face 1
opus error 9 ( has 2 eproms , 2.1 2.31 )
Zx81-16k exp.- Spectrum 48 - Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo-Velleman interface system-Currah microspeech -Ql - 512k exp.- Ql printer - Cst floppy interf.- Double 3.5 floppy- Minerva - Qimi-and much more .
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