Exos

ExOS was developed by J.Schemmel and released by the german paper magazine 64'er in the December issue of 1986. It was published as a ROM patch which copied the original C64 Kernal to $2000 and patched it there. The reader was supposed to use a monitor to save the new ROM then. The ROM is simply burned to an 8k eprom and added to the C64 using a kernal switching board then. ExOS does not require a change on the drive ROM.

REX Datentechnik released Exos v3 as a cartridge (order number 9805).

ExOS Rex Version
From the manual:
CTRL + K	Display drive error channel
CTRL + O	OLD function
CTRL + U	Enable saving RAM under Basic ROM
CTRL + S	Transfer program into RAM floppy
CTRL + L	Transfer program from RAM floppy
CTRL + V	Swap program with program in RAM floppy
CTRL + F	Increases IRQ frequency in drive
CTRL + X	List Basic program from current position
CTRL + Z	List Basic program 50 lines before current position
CBM + F1 and CBM + F3	Transfer screen RAM to RAM drive
CBM + F5 and CBM + F7	Transfer screen RAM from RAM drive
CTRL + A	Disable fast loader

V-DOS by Völkner Electronic (order number 9716) was created by J.Schemmel as well and is said to have similarities. (Dump missing...)

Functionality

• Fast serial load (can be disabled)
• LOAD"$",8 redirected to screen output on direct mode
• Start and end address output
• OLD function
• RAM floppy functions
• some extended LIST support

Notes

• v3 to v4 changes are not yet documented
• ExOS is known to be not the most reliable speeder due to the increased speeding of the stepper motor within the drive

Binaries

Kernal_ROM_all_rr.c64.org_2011-06.rar contains:

• ExOS v3 and v4 kernal.rom
• ExOS patch program
• 64er 12/1986 Exos v3 german manual as pdf

Weblinks

• ExOS at german c64-wiki
• ExOS at retroport.de

ExOS v3 Screenshot