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CST Q+4 Interface
Posted: Thu Feb 20, 2014 8:51 pm
by RWAP
Hmm - I can't imagine this is of any use to anyone, but if someone would like it give me a shout - you can have it for the postage.
This is the small Q+4 interface board which allows the QL to connect up to the large Q+4 four way expansion slot (the big metal box which fits under the QL).
http://www.rwapadventures.com/ql_wiki/i ... ce&lang=en
I will upload the picture onto the Wiki when I get chance, although I note it appears to be missing the 7805 regulator for some reason so DO NOT connect it without checking the power circuitry...
Re: CST Q+4 Interface
Posted: Thu Feb 20, 2014 9:13 pm
by Dave
Dibbs.
Re: CST Q+4 Interface
Posted: Thu Feb 20, 2014 9:21 pm
by RWAP
OK this is on its way to Dave... along with some other bits...
Re: CST Q+4 Interface
Posted: Thu Feb 20, 2014 10:08 pm
by prime
Damn, I have the expansion bay but not the interface card
What are the chips on the card, they look like standard LS types probably just buffers, would be useful if I knew what types. Any chance of a high res scan of both sides of the board ?
Cheers.
Phill.
Re: CST Q+4 Interface
Posted: Thu Feb 20, 2014 10:11 pm
by Dave
Phill, I just want to document it, create a schematic and capture any custom logic, then I can send it on to you. Deal?
Re: CST Q+4 Interface
Posted: Thu Feb 20, 2014 10:22 pm
by RWAP
That sounds a good idea - and Dave you could replace the regulator and check the power circuit at the same time
Re: CST Q+4 Interface
Posted: Fri Feb 21, 2014 2:45 pm
by prime
Dave wrote:Phill, I just want to document it, create a schematic and capture any custom logic, then I can send it on to you. Deal?
Deal,
Having a schematic would certainly help anyways.
Cheers.
Phill.
Re: CST Q+4 Interface
Posted: Fri Feb 21, 2014 2:57 pm
by Dave
After looking carefully at the photos, I can see it needs at least two repairs...
Phill, can you send me some nice, clear photos of what this plugs into? I'd like to understand it as a complete system, not just a single board.
Re: CST Q+4 Interface
Posted: Fri Feb 21, 2014 10:43 pm
by prime
Dave wrote:After looking carefully at the photos, I can see it needs at least two repairs...
Phill, can you send me some nice, clear photos of what this plugs into? I'd like to understand it as a complete system, not just a single board.
Pictures here :
http://penguin.stats.warwick.ac.uk/~stsxab/QL/CST/
First couple are of the interface with the case on then 3 with the case off. The interface board plugs in between the QL expansion bus and the short cable on the left of the interface.
I've also included a dump of the on board eprom. I loaded this into the rom slot in Mess and it is recognized and prints a sign on banner, but doesn't introduce any keywords so I suspect it is a low level driver for the expansion backplane.
The 6821 appears to be connected to a 26 way connector and a 20 way connector I would suspect that the 26 way is a parallel printer port and that the 20 way is something like the BBC's user port.....it's probably wired the same
Let me know if you need me to take any more pics.
Cheers.
Phill.
Re: CST Q+4 Interface
Posted: Sat Feb 22, 2014 1:34 am
by Dave
I am horrified! I can't even imagine what it does to the already shaky signal integrity to have a bus that long - I can only assume the interface card is a fully buffered driver. They can probably pickup the signals from that thing on Mars!
Good job there will be a new, better 1->4 way backplane coming along eventually.