Trump card 2 memory expansion

[jimre]

Dear QL gurus,

Fortunately I could get finally a Trump Card 2. It was the version with no memory. As I have found an old PC ISA video card with the necessary memory chips (4 pcs HY534256AS-70, 2 pcs V53C104AP80). (At least I thought that they will be fine.) and thanks for Vitaliy on this forum for the JED files of the Trump Card 2 PALs (and optionally GALs). So I decided to "upgrade" it to 768K memory...

First I collected pictures on the internet to locate the extra parts on the memory expanded card. I tried to make a drawing of the logic part. (see below) Unfortunately the resistor and especially the capacitor values can't be completely identified from these pictures. According to the drawing I think that these are probably crucial in the correct timing.

It was interesting for me that the IC1 PAL in the Trump card 2 without memory expansion is completely different from the one used in the memory expanded cards.

Now the floppy contoller part works well, but it can't recognise the extra memory. If I POKE to the expanded memory area it is written to it and in most cases can be read back correctly. I can verify Vitaliy's finding that in position IC1, the PAL can be substituted with Lattice GAL16V8D-15LPN, but in position IC2 the GAL performed poorly. Unfortunately I can't get the faster PAL16L8ACN, only an MMI PAL16L8CN. Of course that also can cause problems. When I was using GAL, every 30-40 memory reads failed, PAL performed much better as the error rate was around 1:200. Of course it is not enough for the QL to recognise the memory correctly. Sometimes during the read operations the QL freezed.

Can someone help me with the correct values (and tolerances if available) of R1-R4 and C1-C5 parts? Are the diodes D1-D9 regular 1N4148 ones? If these will be available I can share you the corrected schematics.

Any help and comment would be appreciated! Thank you!

Regards, Imre

Reverse engineered schematics:

Hi res: http://gigant.chem.elte.hu/ZXSpectrum/Q ... c_part.png

The part symbols and locations I used:

Hi res:http://gigant.chem.elte.hu/ZXSpectrum/Q ... ations.jpg

[tetroid]

Hi, Imre.

Thank you for schematic, I still didn't find time for restoring the schematic.

C2 - C5 100pF
C1 - regular 0.22 uF ( power filters )
R1 - 1.8 KOhm 1%
R2, R3 - 330 Ohm 5%
R4 - 820 Ohm 5%
All diodes - 1N4148

I consider that a problem not only in 2V4 PAL type, but also in the used memory chips.
I tried different memory chips, but only on original there was a good result, perhaps, change of values of resistors would bring result, but time is necessary to try. I recommend to use original OKI M514256A-80R.

Can you give IC1 JED for your Trump card w/o memory exparsion ?

Regards, Vitaliy.

[jimre]

Hi Vitaliy!

Thank you for the quick and accurate answer!

I have the original PAL chip, but I have only a German made GALEP-5 programmer, which can program many things, but old PAL support is missing from it. What method do you recommend to read out the chip and archive it?

Regards, Imre

[tetroid]

If you have not PAL programmer, then there is no sense to read IC chip.
I think it difference is not important.

[jimre]

I will ask the shop where they have programmed the replacement PAL to read out the original PAL.

It is important in the manner, that it is worth to archive it.

As far as I remember the unmodified board worked with the 1V4 GAL from the memory expanded board, but after the modification the old PAL can't be used. (it was in December)

[jimre]

I have replaced the capacitors C2-C5 with the correct value. I had a really bad guess with 100nF. Also replaced R1 and R4 (they were 1K before). For R2 and R3 I used the correct values. I still using the PAL16L8CN and the RAM chips I have mentioned before. After these the QL recognized the whole memory:

I would like to thank you Vitaliy! The correct values of the parts were really big help for me. I have left the PAL of the floppy controller only card in the shop, so hopefully I will get the content of it tomorrow.

Of course a comprehensive RAM test will be needed, but so far it is looking good. I also tried the GAL chip, but the boot stopped with white (greenish) screen. With the higher C2-C5 capacitors and the GAL the memory was not recognized, but the QL booted and if I wrote to the memory it is stored and I can read back the data in most cases. Maybe a capacitor value somewhere in between can be good for the GAL, but it is only a guess...

[nikosdoykas]

it will be nice to have the pal readings of the disk card //.... but i search and nobody have it???