Editing Macintosh IIsi (section)

=== ROM ===

* '''ROM Size''': 512 KB
* '''ROM Type''': Usually soldered to the logic board
* '''ROM SIMM Slot''': Present on some units; may contain a ROM SIMM instead of soldered ROMs
* '''ROM ID''': $067C

Some IIsi units shipped with ROMs on a removable SIMM rather than soldered chips. The IIsi ROM is reportedly compatible with the [[Macintosh SE/30]] and may provide 32-bit clean operation when installed.<ref>{{cite web |url=https://lowendmac.com/1990/mac-iisi/ |title=Mac IIsi |publisher=Low End Mac |access-date=2026-02-09}}</ref>