[comp.sys.atari.st] Mega 2-> 4Meg?

mts10271@uxa.cso.uiuc.edu (10/17/90)

	Does anyone have docs on how to upgrade a Mega 2 to 4 Megs?
I have checked my motherboard and all the traces seem to be there, so
it seems to be a matter of adding the rams and capacitors. The rams
should be no problem, but I need to know what capacitance the capacitors
should have, if there are any jumpers that need to be connected, etc.
If anyone has pulled this off, please drop me a line.

						Thanks,
						Mike Stepniczka
						mts10271@uxa.cso.uiuc.edu

fortinp@bwdls56.bnr.ca (Pierre Fortin) (10/18/90)

In article <46300103@uxa.cso.uiuc.edu>, mts10271@uxa.cso.uiuc.edu writes:
> 
> 	Does anyone have docs on how to upgrade a Mega 2 to 4 Megs?
> I have checked my motherboard and all the traces seem to be there, so
> it seems to be a matter of adding the rams and capacitors. The rams
> should be no problem, but I need to know what capacitance the capacitors
> should have, if there are any jumpers that need to be connected, etc.
> If anyone has pulled this off, please drop me a line.
> 
> 						Thanks,
> 						Mike Stepniczka
> 						mts10271@uxa.cso.uiuc.edu

The worst part about this upgrade was sucking the solder out of the over 300
holes; don't use your lips or a straw:  possible lead poisoning.  :^)  :^)

The capacitors are 0.22uF 50V Ceramic Axial types (C80-C111) [available 
from Best Electronis as a kit of 16]
Three resistors (33 ohm 1/4w) must be added; near the front edge of the 
board in the center.
DRAM (1Mx1).  I'm running 70ns parts in the additional 2-Meg, but I think 
you can go as slow as 120ns.

4-Megs is great! Big Ramdisks! "Out-of-memory" no more! :^)

Good luck,
Pierre
Pierre Fortin       Bell-Northern Research     I know, my postings are
Internet Systems    P.O.Box 3511, Stn C        terse and humourless. So?
(613)763-2598       Ottawa, Ontario            RIP: aptly named protocol
fortinp@bnr.ca      Canada    K1Y 4H7          AppleTalk: Adam&Eve's design