TrumpCard modification

[Cristian]

Recently I heard about an useful modification for some TrumpCard models. It promises to prevent heat and improve stability.
I tried some search but with no results. Unfortunately my information are defective: it should be something about adding a resistor on the top-right angle of the board, but I don't know exactly which kind of mod is it.
Could anyone help me please to understand if my Trumpcard needs this mod or not please? How can I exactly identify my board model? Does it need some further modification?

[Derek_Stewart]

Hi,

You could replace the 7805 voltage regulator with a TSR 1-2450 which is a drop replacement for the 7805. With the advantage of no heat.

I have fitted them to QoLs, Spectrums ZX81s etc all wlork a lot cooler.

The QL conversion does away with the heat sink, makes the microdrive run cooler.

[Cristian]

Hi,

You could replace the 7805 voltage regulator with a TSR 1-2450 which is a drop replacement for the 7805. With the advantage of no heat.

Thank you very much for you important information
Anyway, even if I'm almost sure mine is not the so-called TrumpCard2, on the other hand some questions still remain...
I couldn't find the article talking about the top-right resistor modification, but I found an old ad (September 1990) presenting the "new" TrumpCard (please see below).
So my confusion has increased
Could anyone help to identify my 768K board model please?

[XorA]

A quick look at google and it appears Trumpcard 2 says Trump Card 2 in giant letters in the space saved by only having 6 ram chips

[janbredenbeek]

A quick look at google and it appears Trumpcard 2 says Trump Card 2 in giant letters in the space saved by only having 6 ram chips

You probably meant this picture:

The 6 RAM chips are actually M541256 ones with 256K x 4 bit each. Cristian's card is the original one with 24 x 256Kbit RAM chips.

Jan.

[Cristian]

A quick look at google and it appears Trumpcard 2 says Trump Card 2 in giant letters in the space saved by only having 6 ram chips

Yes I do know the TC2 an this is the reason why I told I'm sure it's not mine.
Let's focus to the real questions:
1) Was the ad talking about the TC2 or...?
3) How many 768K versions do exist and which model is in my possess?

[Cristian]

[quote="jCristian's card is the original one with 24 x 256Kbit RAM chips.
Jan.[/quote]
Do you mean the very first model?

[XorA]

A quick look at google and it appears Trumpcard 2 says Trump Card 2 in giant letters in the space saved by only having 6 ram chips

Yes I do know the TC2 an this is the reason why I told I'm sure it's not mine.
Let's focus to the real questions:
1) Was the ad talking about the TC2 or...?
3) How many 768K versions do exist and which model is in my possess?

256K x 4 bit is 1 megabit so its talking about the TC2

You have the original! (of which there maybe minor revs but one of the experts will have to comment on that).

[janbredenbeek]

256K x 4 bit is 1 megabit so its talking about the TC2

Yes, but the RAM chips are really 4 bit ones. There's a circuit diagram in the same directory (http://gigant.chem.elte.hu/ZXSpectrum/QL_Trump_Card/) where the picture resides and that clearly shows each chip has 4 data lines.

You have the original! (of which there maybe minor revs but one of the experts will have to comment on that).

I guess the V2 Trump Cards are very rare. By 1991 the Gold Card was introduced and Miracle Systems had a trade-in offer for Trump Card owners. I still have the invoice (I got GBP 80.59 back from GBP 291.18 - weird looking numbers but I bought it cash with Dutch Guilders at an Eindhoven meeting).

Jan.

[XorA]

256K x 4 bit is 1 megabit so its talking about the TC2

Yes, but the RAM chips are really 4 bit ones. There's a circuit diagram in the same directory (http://gigant.chem.elte.hu/ZXSpectrum/QL_Trump_Card/) where the picture resides and that clearly shows each chip has 4 data lines.

That still makes 1 megabit, so I am a little confused what you mean!