[comp.sys.atari.8bit] 64K for Atari 400.

levi@kodak.UUCP (Ilia Levi) (03/22/89)

Does anybody have instructions on how to upgrade Atari 400
to 64K using 64Kbit chips?

clf3678@ultb.UUCP (C.L. Freemesser) (03/22/89)

I don't believe that you can expand a 400 to 64k.  The highest it will
go (the highest I've ever heard it can go) is 48k.  I believe Axlon made
a board that did this, and POSSIBLY Atari had one at one time.  If you
want 64k, you will have to get an XL/XE.

=cf=

jcbst3@cisunx.UUCP (James C. Benz) (03/31/89)

In article <483@ultb.UUCP> clf3678@ultb.UUCP (C.L. Freemesser (709ITP)) writes:
>I don't believe that you can expand a 400 to 64k.  The highest it will
>go (the highest I've ever heard it can go) is 48k.  I believe Axlon made
>a board that did this, and POSSIBLY Atari had one at one time.  If you
>want 64k, you will have to get an XL/XE.
>
>=cf=

Oh yes you can, but the 400 can only access 48K without bank switching.
I have a 400 at home (in the closet now - unused) with 64K and a variety
of BASIC (yecch) programs that use the extra 16K.  Haven't used it in a
*long* time (since I got 800XL as a gift) but it requires poking a value
into some register telling the processor to access the other bank.  There
were at one time several 64K upgrades for the 400, but none that I know of
now.  installation of the upgrade board required soldering two jumpers on
the motherboard (yikes!) so it's not a trivial upgrade.


-- 
Jim Benz 		     jcbst3@unix.cis.pittsburgh.edu     If a modem 
University of Pittsburgh					 answers,
UCIR			     (412) 648-5930			 hang up!