Interestingly, the MegaDemo was not compatible with the ROM 3 version of the IIgs and required an additional patch to be run on that model.

UniDisk 3.5 support (ROM version '0')

Memory Expansion fix (ROM version '4')

Support for the HP Integral PC (embedded ROM version).

Original firmware release ("ROM version 00")

This bug was fixed in later ROM versions.

Commodore 65 preliminary documentation (March 1991), with addendum for ROM version 910501.

SDK-51 used the external ROM version of the 8051 (8031).

The final ROM version was 1.19-6.

This fixed many bugs and was the first ROM version to be produced in quantity.