Expert: Gregory Donner - 11/12/2007

Question
QUESTION: A year ago I was given this computer by a friend who didn't have any docs.
Since then I've intermittently tried to add memory. I bought two 32Mb
double-sided non-EDO RAM chips for the daughterboard but they're not
recognized. I also couldn't get more than two of my four 4Mb chips on the
motherboard recognized.

It's a rev 4 machine and I'm not sure the online docs are right: does anyone
know what jumpers should be ON?

ANSWER: Hi Gary,

If you have either the Commodore or Amiga technologies A4000T, here's some detail about the motherboard RAM limit/usage (from The Big Book of Amiga Hardware):

http://www.amiga-hardware.com/showhardware.cgi?HARDID=31

http://www.amiga-hardware.com/showhardware.cgi?HARDID=4

"The A4000T contains 4 x 72pin SIMM slots for adding up to 16MB of RAM in addition to the 2MB of Chip RAM surface mounted on the motherboard. SIMM sizes of 1MB, 2MB, 4MB and 8MB can be used. Please note, than even though it is possible to use 8MB SIMMs, you are still limited to 16MB on the motherboard. If 8MB SIMMs are used, only 2 SIMMs can be used and they must be inserted in alternate slots."

Unfortunately, it doesn't say anything about RAM usage on the daughterboard, but there are some jumper settings listed that may be helpful.

I hope this helps!

Greg

---------- FOLLOW-UP ----------

QUESTION: Hi Greg,

The first picture just shows one bank of RAM slots. Mine has two. I'm wondering
now if I haven't put RAM in the wrong banks. Do the jumpers control the
motherboard or daughterboard RAM?

Answer
Hi Gary,

I wish I could tell you for sure, but unfortunately, I can't. :( There's very little information that I've been able to find on the daughterboard (searching via Google), so the only place I can think of is asking on UseNet's comp.sys.amiga.misc and comp.sys.amiga.hardware newsgroups:

http://groups.google.com/group/comp.sys.amiga.misc?lnk=gschg

http://groups.google.com/group/comp.sys.amiga.hardware?lnk=gschg

There should be some people there who either have an A4000T themselves, or know of someone who does who can answer that question.

I'm sorry I can't be of any further help :( This piece of hardware seems very elusive. :(

Greg