OSI 600D Superboard Build

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rubber_jonnie
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

So I decided to test every key on the keyboard, and found that 2 work.

Key 7 stops the screen flickering, though I have no idea why, and the - key causes it to drop into what looks like a monitor mode with four zeros top left and a hex value to the right of it, a bit like this:


0000 3B

All a bit odd.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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rubber_jonnie
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

rubber_jonnie wrote: Wed Mar 20, 2024 3:55 pm So I decided to test every key on the keyboard, and found that 2 work.

Key 7 stops the screen flickering, though I have no idea why, and the - key causes it to drop into what looks like a monitor mode with four zeros top left and a hex value to the right of it, a bit like this:


0000 3B

All a bit odd.
EDIT: What happens when I press the - key is what should happen when I press the M key at the start menu.

Also I just nearly got to boot to basic, and I got as far as memory size? but hitting return only gave me a - sign, but other keys were working. It's odd that I wondered if my shift lock switch was causing issues and since I removed it the flashy screen has gone and it's solid as a rock, but none of the keys work again!!! Grr.

Annoyingly I didn't get pictures!!!

I think this is now just a faulty keyboard issue, and the KBD logic is just 4 chips so I'll have a look at the soldering and make sure nothing is wrong.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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rubber_jonnie
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

OK, well that was annoying. I decided to reflow the sockets for the LS125's and flipped it back over, powered on and got a screen full of garbage again! Whaaat!!!

Some troubleshooting later I find that if I take U4 & U5 out (These send some of the keyboard data onto the data bus) and the machine boots to the D/C/W/M ? prompt again.

So I test the 2 74LS125s I just took out and bothe are bad. Whaaat!!! again.

So I need to order some more and see what happens when I put working ones in. Maybe it'll work. Perhaps, fingers crossed.

Would explain why the keyboard wasn't working though.

EDIT - One of the LS75's is dead too :pullhair:
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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stephen_usher
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Re: OSI 600D Superboard Build

Post by stephen_usher »

Oh, that's annoying! You've not been rubbing your feet on the carpet before touching the board whilst playing with a Van de Graff generator have you?
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

stephen_usher wrote: Wed Mar 20, 2024 9:42 pm Oh, that's annoying! You've not been rubbing your feet on the carpet before touching the board whilst playing with a Van de Graff generator have you?
I don't even own a Van de Graaf Generator (Note to self: Buy Van de Graaf Generator)

I think something else hinkey is going on with the KBD side of things, but need the spares before I can start to look into it. Hopefully they'll be here soon.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Re: OSI 600D Superboard Build

Post by stephen_usher »

You do seem to be having a high TTL death rate somehow.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

stephen_usher wrote: Wed Mar 20, 2024 10:08 pm You do seem to be having a high TTL death rate somehow.
Yeah, it's not good. Need to go through the whole kbd circuit and see if I can figure out what the heck is going on.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

Bloody hell. I just tracked the /RKB line from U20 to where it sends an enable signal to the LS125s and LS75s that form the KBD circuit.

That's dead too...

No signal on the LS138 and subsequently none

More ordered.

WTF is going on?

If I swap with one of the other LS138s I get a good signal. This is all rather annoying.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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PhilC
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Re: OSI 600D Superboard Build

Post by PhilC »

It does sound like a power supply issue. I bet all those logic chips shared the same GND or +5V
If it ain't broke, test it to Destruction.
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Re: OSI 600D Superboard Build

Post by rubber_jonnie »

PhilC wrote: Thu Mar 21, 2024 11:28 am It does sound like a power supply issue. I bet all those logic chips shared the same GND or +5V
I don't think so, it's a bench PSU with the voltages and OCP dialled in. Maybe just crap chips. Probably re-branded MOS ICs :fire1:

And of course I don't have any spares in stock...
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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