[comp.sys.atari.st.tech] AERCO board hacking

feat@max.bnl.gov (john feat) (09/20/90)

	I think I've seen it asked a few times, but never seen anyone give
the details:
	What has to be done to the AERCO ram board to rework the 256K bank
to use 1M parts?  The sockets are the right size (yes I already have 2M worth
of chips in the other bank), but originally contained 256K parts so I believe
some trace cutting/jumpering is needed.

	Also if I do get that bank active, should I worry about removing
power from the .5M bank on the (520)ST main board to alleviate the drain on
the power supply as much as possible.  If so, do I have to clip the Vcc leads
of all the chips or is there a more elegant way?

	Thanks.

guidrax@wet.UUCP (mike guidry) (09/24/90)

I suggest that you call Aerco for the upgrade docs.  The phone # is 512-451-5874
I was going to upgrade my 520 all the way to 4 megs, but after I saw what had
to be done to go from 2.5 to 4 megs, Idecided to get the board for my 1040
instead.  It goes to 4 megs with no mod needed.  The mods to the 520 board are
extensive:  replacing 33 resistors, cutting traces and jumper and adding a 
number of jumpers.  If you're not good with a soldering iron, Aerco will do it
for $40.