Apple IIc ROM versions

Apple IIc ROM versions:

ROM version '255' (original)
ROM version '0'
Consisted of a chip swap and minor motherboard modification
Added support for UniDisk 3.5
Mini-Assember added
Monitor "Step" and "Trace" commands added
Rudimentary support for AppleTalk
ROM version '3'
New motherboard
34-pin socket added for plugging in a memory card up to 1 MB
AppleTalk support removed
Keyboard color changed from beige to platinum
ROM version '4'
Better detection of installed RAM chips
Correction of a problem when using the serial modem port in terminal-mode
Bug fix for keyboard buffering

To determine the ROM version in your Apple IIc, type PRINT PEEK (64447) at the command prompt. The ROM version is returned by the IIc as follows:

PEEK (64447) Responses:
255 - original ROM version '255'
0 - ROM version '0'
3 - ROM version '3'
4 - ROM version '4'