GEOS is a disk-based "Graphic Environment Operating System" for the Commodore C64 and C128 computers. To speed up the boot process and the task of switching between programs on a Commodore C128, parts GEOS can be put into a 32KB ROM. This ROM can then be installed into the internal function ROM slot U36.
This is the text from the original readme by the creator of the ROM:
"Burn one of these files into a 32k EPROM and insert it into the U36 socket in C128. You can bypass its execution by holding the RUN/STOP or C= key during power-up or reset. It will drop you into the machine monitor (C128 mode, exit by 'x') or C64 mode.
These three files contain GEOS Kernal only. You still need a boot disk with at least Desktop (but existing auto-execs will be executed before that). Boots always to 80-column mode; not much can be done about that. It is somewhat tuned to have a centered screen on my TV set so you might have visual problems. Anyway, after the Desktop is loaded, press RETURN twice, and you will switch into 40-column mode.
There are three versions:
- Geos128Am1571 - American version with 1571 as device 8
- Geos128Am1581 - American version with 1581 as device 8
- Geos128Ge1581 - German version with 1581 as device 8
They contain raw data, and there is no load address."
You can download the complete GEOS 128-V2 disk images, ROM images, and ROM chip labels from here.
You can see the effect of the installed ROM in my video "Booting GEOS 128 with GEOS Function ROM on a Commodore 128".
If you can't burn the EPROM yourself, choose which version you require and send a short mail titled "GEOS 128-V2" to jac at "wudsn.com". I can burn the EPROM on request and send them.
If you have questions regarding GEOS and how to use it, please ask questions in a Commodore forum. I am not a GEOS user; I only provide the EPROMs as a service.