5v or 3,3 volt SIMM's

[rkauer]

 3.3V SIMM are used mainly on printers.

 But it is easy to know if they are 5V or not: just look at centre of the SIMM. 3.3V ones have a voltage regulator (normally a "round" chip).

[rkauer]

voyager wrote:
--zip--
The Derringer has 9 GAL’s . The board is 16 years old now and the GAL’s will work for another 4 years after that its going to lose its programming.  Well oke not directly but the will fail.

--zip again--

So what do you think, is it a good idée to make backups or not?

 Yes, it's a good idea. Only one major problem: PAL (and GAL) have a read-protection bit who could be set (or not, depends on the programmer/owner), as the same as the PIC series.

 If the chips are not protected, yes, is a good thing to do.