Model 35SX (8535) and 40SX (8540) BIOS Versions

27C512 x2: 'U19' (EVEN) and 'U31' (ODD)

92F1502 (E)
92F1503 (O), 04/04/1991, Revision 6

04G2022 (E)
04G2021 (O), 09/25/1991, Revision 10

10G4128 (E)
10G4127 (O), 03/1x/1992, Revision ?