[comp.sys.atari.st] RAM upgrades for 520ST

bediako@cs.buffalo.edu (Bernard Bediako) (10/10/89)

Can anyone tell give any recommendations on the best solderless ram
upgrade kits?  Right now I'm heading toward the EZ ram II.  I need to know
any comments/problems there are with it.
	Also, does it matter what speed (ns) chips I use?  Will there be any
problems using 100 or 80ns chips?  Will things speed up if I use 80ns chips?
(I'm planning on using 1M * 1 chips).

		thanks
		bernie			bediako@cs.buffalo.edu
Bernard Bediako  --------=-=-=-=-=->	DOMAIN:	bediako@cs.buffalo.edu

krieg@jupiter.uucp (Andrew Krieg) (10/10/89)

In article <11562@eerie.acsu.Buffalo.EDU>, bediako@cs.buffalo.edu (Bernard Bediako) writes:
> 
> Can anyone tell give any recommendations on the best solderless ram
> upgrade kits?  Right now I'm heading toward the EZ ram II.  I need to know
> any comments/problems there are with it.
> 	Also, does it matter what speed (ns) chips I use?  Will there be any
> problems using 100 or 80ns chips?  Will things speed up if I use 80ns chips?
> (I'm planning on using 1M * 1 chips).

I bought an EZ Ram II about 2 years ago.  They had just changed the board
design and it didn't work when I received it.  I had to return it twice
before I got one that worked.  They did refund all of my shipping charges.

Since then it has been working great.  I started with the 256K bit chips and
just recently bought the 1M bit chips.  Still running strong, never
misbehaves.

The ST can't make use of any speed increase in chips above 150 ns.  EZ Ram II
recommends 120ns chips however.  I bought 100 ns ones, mainly because they
are more reliable (and durn cheap now!).  Not many places carry the 120ns 1M
chips, and the 100ns ones are usually only a quarter or so more a piece.

It's great to have a 2.5 Meg machine :^)

Now a question of my own.  Could I use my 256K bit chips I replaced in one of
those cartridge RAM expanders every one is talking about on this board?
Would I be able to have 3 Meg?  Or won't it work with another expansion
already in place?  If it would work, how much are those carts with no RAM?


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dmk@cbnewsi.ATT.COM (daniel.m.kuster..jr) (10/18/89)

I currently have a standard 520ST that I
would like to upgrade to 2.5 Meg (I already 
have the 16 1 Meg chips).

Could someone please summarize the hardware
changes required to convert a stock 520ST to
2.5 Meg?  I have build hardware projects before
and would rather do the modifications myself.
Besides, the RAM chips I have are surface mount,
not DIP, so they wont work with any of the RAM
boards that I know of.

Thanks in advance,

dan k.