Paxar 656 / 636 - Manual (Page 68)

62 • Appendix B Users Manual Model 656/636
Diskless Rom Board P/N 281164
DISKLESS ROM BOARD, Upgradeable software I.C.'s include U12, U16, and U20.
Position new I.C.'s in same orientation as pictured above.
SWITCH POSITIONS,
SW1: 1 and 6 = OFF, 2 thru 5 = ON,
SW2: 1 thru 4 = ON
Head Driver Board P/N 351106
(Use chip removal tool p/n. 351156 for square I.C.'s)
HEAD DRIVER BOARD, Upgradeable software I.C.'s include U1, U2, U8, and U18.