Having my IIfx ROM SIMM in front of me:

4 ROM Chips labled with

KM23C101 0G-12

9101

341$07.. 81 (82,83,84) different numbers on the Chips!

and a copyright by Apple 1990.

On the bottom under the Chips:

U1 U2 U3 U4

Its a "army dark" green card, 64-pinner

On the back side:

SAMSUNG

KMM532128RP-01

103 SM

341-0811

94-VO

This one was installed in my MacSE/30 - on the stratup it crates the SimasiMac for 5 seconds then starting the patched 8.1.

Sadly now after booting it up after a year it restarts often and shows the Simasi the hole time... welcome SimasiMac...

I try now my IIsi ROM SIMM because I heared that this one does not have the Simasi effect. I let you know about the results.