The Sinclair QL Forum

Hi all,

Does anyone know if the schematic for the Miracle Trump Card exists online anywhere, I'm trying to add
support for it to Mess. If it's not online I can trace the circuit out, or enough of it to work out how the disk interface part works it'll just take longer.

Cheers.

Phill.

I don't think it exists online - I spoke to Stuart Honeyball recently (who was part of the Miracle team) - he doesn't have any of the information any longer.

Can anyone confirm what the memory chips are used in the original Trump Card - I have one here which doesn't report any extra memory, but it seems to have a mixture of RAM chips (53C256LS-10 and 41256P-10)

RWAP wrote:Can anyone confirm what the memory chips are used in the original Trump Card - I have one here which doesn't report any extra memory, but it seems to have a mixture of RAM chips (53C256LS-10 and 41256P-10)

The one I have has 41256-12's on it but looking at the datasheet for the 53C256s they seem to have the same pinout so it should work.

http://pdf1.alldatasheet.com/datasheet- ... C256F.html

You could of course try the chips in another Trumpcard, or an Expanderam, which uses the same chips.

Cheers.

Phill.

Hmm I would have to replace all 24 chips to see if the Trump Card works...

An expanderam has 16.

Now from 4 working uncased expanderams, I have a right mixture of 10ns, 12ns and 15ns (some have mixed ones, but only 24 of the 15ns chips, so I guess I will have to try those)

I noticed the oscillator is also loose, so may just have to resolder that

If you remove the EPROM, then remove 16 of the 24 ICs in the higher address range, and just test the bottom 256K.

If it tests ok and you get 384K, swap in the next 256K and test that. When you have a known good 256K and a known bad 256K, swap in each IC from the bad batch until you identify the bad IC.

Removing the EPROM forces the memory to just be addressed directly with no fancy tricks.

I don't know which end of the map is the low map in terms of IC sockets, but if you try one end and it shows as 128K, it's the opposite end

I think it might be the crystal which has gone, as even after resoldering it is still very wobbly - so I guess one of the legs may be broken....

Dave wrote: Removing the EPROM forces the memory to just be addressed directly with no fancy tricks.

I don't know which end of the map is the low map in terms of IC sockets, but if you try one end and it shows as 128K, it's the opposite end

Mind leaving the TC eprom in, at least it tells you how much memory you have on start up, and with only 256K addon it shouldn't be clashing with the RAM.

I think the lowest bank is the one next to the eprom and 177x.

Cheers.

Phill.

Might be worth asking Ron Dunnett (Qubbesoft) about the Trump Card diagram. He sold Trump Cards for a while after Miracle stopped doing them. Haven't got an up to date contact details for him though, sorry.
Dilwyn