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CST RAM-Plus, large pics thereof

Posted: Fri Nov 08, 2019 5:07 pm
by Chr$
I've had this for a 6+ months and it didn't work. It looked like a previous owner had messed with it and there was some messy soldering and something or other missing from the PCB. It was so messy, I couldn't even see that the missing component had 3 pins. I looked into it further today and thanks to the Sinclair QL Wiki (which contains a copy of the original paperwork) I discovered that all that was missing was a 7805 regulator! So I popped one on and tried it out. The regulator got very hot indeed. I turned it all off quickly and noticed that the regulator should actually be attached to the alu black outer housing. Sorted that, found some replacement screws and all is fine now, it works properly. I like that it has space for Eproms on it.

I noticed that there aren't really any decent pics of the CST RAM-Plus anywhere online, so here are some, from various angles and also of the innards. Perhaps it may help someone in the future if they google and find this post (not sure if the pics will be re-sized here - I have larger versions). Feel free to use them on the QL Wiki. PCB is labelled CST RAM-Expander, C 1986 Issue 3.

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Re: CST RAM-Plus, large pics thereof

Posted: Fri Nov 08, 2019 5:11 pm
by Chr$
And a few more pics..

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Re: CST RAM-Plus, large pics thereof

Posted: Fri Nov 08, 2019 5:12 pm
by Chr$
Sorry, one more, didn't quite all fit in the 2 messages...

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Re: CST RAM-Plus, large pics thereof

Posted: Sat Nov 09, 2019 7:39 am
by klausfrank
Great pictures.
Thank you very much. I have one myself - and it is working. There is room for eproms, but I miss the ic above the eproms.
It would be nice with a schematic of the IF.

Re: CST RAM-Plus, large pics thereof

Posted: Sat Nov 09, 2019 9:22 am
by Pr0f
Not sure if there is a schematic, but the paperwork does outline what LS TTL chips and transistor are required - I made the mods on one of these to put 4 sockets in for the eproms - seemed to work out ok with a TK2 Eprom in one of the slots.

Re: CST RAM-Plus, large pics thereof

Posted: Sat Nov 09, 2019 9:50 am
by Chr$
I couldn't find a schematic either, but here is a copy of the paperwork from Dilwyn's site which shows the 2 logic chip types next to the Eproms:

http://www.dilwyn.me.uk/docs/manuals/cstramplus.pdf