605 Expansion Board:

R1.1 -- old. bad. flaky with many SCSI devices. R1.2 -- current. mediocre. most SCSI devices work.

R1.1 -- old. works with first development board (with pot).

R1.4 -- final version of ROMs for first board (with pot, R1.4 ROMs work with both consumer & 605).

R1.2 -- old. works with last development board (no pot).

R1.3 -- final version. of ROMs for last dev. board (no pot, compatible with consumer & 605 players). R1.5, R1.6 -- internal Philips ROMs for last development board not sent to any customers I know of.

R2.1(Consumer)--ROMs for release cart used on consumer.