Last modified: Sep 04, 2018, Page views: 2553
GEORAM 512K Clone
Cartridge, Box and Manual
GEORAM was first released in 1990 by Berkley Softworks. It was a 512K Ram Expansion Unit that was
explicitly supported by GEOS. The original was discontinued in 1993.
Shareware Plus is now offering a 100% compatible clone of the GEORAM 512K. It is much more
affordable, comes in a much smaller package (the size of a standard game cartridge), and draws
less power than the original.
The GEORAM is in a professionally labeled white cartridge case, and comes in a similarly nice
product box with printed user manual.
Here's what the original looked like, for comparison with the new version which can be seen on
Despite being called GEORAM, there is nothing inherent about how it works that limits
its use to GEOS. It was named like this because it was produced by Berkley Softworks, the company
that created GEOS, and they shipped it with software support in GEOS. But other software for the
64 does make use of it, and any new software can easily be written to take advantage of it.
The GEORAM is not compatible with Commodore's 17XX REUs, and the related clones of those REUs.
GEORAM is a significantly simpler and more limited product, however it is easier to produce as it
does not depend on the Ram Expansion Controller (REC) chip that is no longer being produced.
A standard REU is controlled by issuing commands to the REC chip to transfer or swap memory
between arbitrary addresses of the C64's main memory and the REU's internal banks. GEORAM on the
other hand offers a simple paged scheme. One page of C64 I/O ($DE00 to $DEFF) is a direct access
to a 256 byte block of the GEORAM's memory. Write–only registers at $DFFE and $DFFF control which
block of the GEORAM's memory will appear to the C64.
For more detailed technical information, refer to the
GEORAM article on C64 Wiki.
For more pictures and a comparison of the logicboards of the original and the new GEORAM, checkout
this blog post, on World of Jani.
C64OS.com is hosted on a Digital Ocean droplet.
Digital Ocean is a cloud hosting platform, built for developers. They make it simple
to get started. They have intuitive administrative tools and reasonable prices. And
they can scale as your needs grow.
If you sign up with this referral link, you'll get a $100 credit, and after you've
spent $25, I'll get $25. If you are looking for a cloud platform to host your website
or web app, this is win–win.
Want to support my hard work? Here's how!
The new GEORAM 512 RAM Pack is now in stock.
Simply plugs in your cartridge port and adds 512K RAM to your Commodore 64/128.
Originally designed by Berkeley Softworks just for GEOS v2.0r,
but later supported by lots of software releases.
Supplied boxed with cartridge & manual.
In Issue 83 of Compute! Gazette, May 1990, there appeared an article introducing the then new