CBM-II 24K RAM Cartridge

From: Mike Naberezny <mike_at_naberezny.com>
Date: Sun, 02 Dec 2012 17:58:29 -0800
Message-ID: <50BC0745.5000606@naberezny.com>
Hi,

I've been doing some B128 (610) programming lately and I ran out of space in 
the tiny 1K RAM area in bank 15.  To get more RAM in bank 15, I modified a 
Handic ROM cartridge.  This ended up being very simple to do and requires 
adding only one 74LS00.

If you have a CBM-II cartridge, it's likely to be this same board.  The 
cartridge normally holds two 2764 EPROMs.  I replaced these with two 6264 
SRAMs (total 16K).  I also piggybacked another 6264 to max it out at 24K.

I have photos and the schematic here:
http://mikenaberezny.com/projects/cbm2-24k

It's equivalent to Gary Anderson's 24K cartridge (see "Hardware Add-ons"):
http://www.6502.org/users/sjgray/computer/cbm2/index.html

Regards,
Mike

-- 
Mike Naberezny (mike@naberezny.com) http://6502.org


       Message was sent through the cbm-hackers mailing list
Received on 2012-12-03 02:00:05

Archive generated by hypermail 2.2.0.