Re: Putting a RAM chip in U36 on a C128

From: Spiro Trikaliotis (
Date: 2002-08-21 20:44:19


MagerValp wrote:

> >>>>> "NR" == Niklas Ramsberg <> writes:
> NR> Anyone willing to help me out here?
> If you have a battery backed up S-RAM that's pin compatible with a
> normal 6264, such as the Hyundai HY6264ALP, it's as simple as matching
> the pins on the chip to those in the socket. The only signal that
> isn't available is the R/W line -- you'll have to bend up that pin and
> connect it via a wire to somewhere else on the motherboard. R/W is
> available all over the place, check the schematics.

I don't know that much about U36 on the C128, but are you sure that
the PLA gives a CS if you try to write to that area? It might be
something like the "RAM-under-ROM"-syndrome on the C64, where you
can write to the RAM under KERNAL or BASIC while the ROM is selected.
If the CS is not generated on write, the R/W logic is not that simple 

Just a question,

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