Re: 8096 repair

From: Baltissen, GJPAA (Ruud) <>
Date: Tue, 1 Feb 2011 07:31:44 +0100
Message-ID: <>
Hallo Hervé,

> I've understood your message - replacing 4116 with
> 4164 is bad ! I definitely won't try .....

May be I should have been more clear: if you replace the 4116 directly by the 4164, you will blow up the last one. But if you take some precautions, it is no problem. The most simple thing is bending pin 1 and 8 out of their sockets and the connecting pin 8 with pin 9. Should work but the problem is that you can only use 16 KB of the 64 KB. If you want to use the full 64 KB, pin 8 has to be connected with +5V and pin 9 to a multiplexed address line. If you go a step duther and connect pin 1 to a multiplexed addrress line as well, you can use the 41256 and have 256 KB of RAM at the end. But think of the right number of refresh lines, eight in this case.

The above idea works, it enabled people to turn a 16 KB Elektor/Elektuur card into a 64 KB one. You had to cut some lines, remove a handfull of capacitors and solder some new lines. In this case it was relatively easy: the power supply lines were at the end of the board/path. If the power supply lines are in the middle of the board/path and have a lot of junctions, you have to be very carefull. Forget one to cut and you even run the risk of blowing up parts. Forget one to reconnect again and the board most probably won't work again.

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