This is the relationship between the indicator panel cable slots in the backplane for the RF11, and the sections of the indicator panel display for that controller: A31-1 Top left A31-2 Second left A32-1 Third left A32-2 Bottom left B31-1 Top right B31-2 Second right B32-1 Third right B32-2 Bottom right Going on the assumption that the same relationship exists for the RK11-C, I have worked out what the contents of the RK11-C panel would have been. (If I have that assumption wrong, there might be a left-right inversion, or possibly a vertical inversion - but each vertical pair of line halves has a fixed relationship, as they are the '1' [component] and '2' [back] sides of card edge where the finger contacts are.) Here is the actual light pattern (unused lights are marked with '-'): XXXXXXXXXXXXXXXX--XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX-X X-XXXXXXXXXXXXXXXXXXXXXXXXXXXXX---XX XXXXXXXXXXXXXXXXXXXXXXX-XXXXXXXXXXXX A very full insert! Here are the detailed contents of the left four rows of lights (top to bottom), and then the right four rows. Signal names are from the RK11-C prints; meaning is from the RK11 writeup in the Peripherals handbook (if un-marked), from the prints (if marked '[]'). Caption (where it differs from the signal name) is sometimes taken from bit names in the Peripherals Handbook writeup, and sometime notional (if marked '[]', since it appears that DEC may never have produced an insert for the RK11-C; these are suggestions to put on a newly-created RK11-C insert). Captions of the form '[XXX-N]' are intended to have the label above the bar, and the digits below. The left upper light group appears to contain the Control Status Register, the lower left group is the Drive Status Register (basically - there are two extra bits there which are not in the CSR), the lower middle right is the Error Register (ditto). Signal Caption Meaning ERROR [ERR] HE Hard Error SCH CMP SCP Search Complete MAINT Maintainence (RK11-C only) INH BA [IAI] Inhibit increment of BA FMT Format R/W A [RWA] Read/Write/All (RK11-C only) SSE Stop on Soft Error CONTROL READY RDY/[CR] IDE Interrupt on Done Enable EX MEM 01 MEX/[XM-1] EX MEM 00 MEX/[XM-2] FUN 02 [FUNC-2] Function FUN 01 [FUNC-1] FUN 00 [FUNC-0] GO - - RKDA 15 RKDA 14 RKDA 13 RKDA 12 RKDA 11 RKDA 10 RKDA 09 RKDA 08 RKDA 07 RKDA 06 RKDA 05 RKDA 04 RKDA 03 RKDA 02 RKDA 01 RKDA 00 PO?LE HEADER OK [HOK] RK BUS MASTER [BM] - ADD 15 ADD 14 ADD 13 ADD 12 ADD 11 ADD 10 ADD 09 ADD 08 ADD 07 ADD 06 ADD 05 ADD 04 ADD 03 ADD 02 ADD 01 ADD 00 INT REQ [IRQ] Not in DSR WC OVF [WCO] Not in DSR ID 2 ID/[DID-2] Identity of Drive ID 1 [DID-1] ID 0 [DID-0] DPL Drive Power Low HI DEN HDEN/[HD] RK05 DRIVE UNSAFE DRU SIN Seek Incomplete STD SEC PLS SOK Sector Counter OK DRY Drive Ready R/W/S RDY [RWS] Read/Write/Seek Ready WT PROT STATUS WPS SC=SA [SEQ] Set when heads over sector in RKDA RKDS 3 [DSC-3] Sector Counter RKDS 2 [DSC-2] RKDS 1 [DSC-1] RKDS 0 [DSC-0] RKDB 15 RKDB 14 RKDB 13 RKDB 12 RKDB 11 RKDB 10 RKDB 09 RKDB 08 RKDB 07 RKDB 06 RKDB 05 RKDB 04 RKDB 03 RKDB 02 RKDB 01 RKDB 00 LAST WORD DONE [LWD] RD GATE [RDG] DSB 15 DSB 14 DSB 13 DSB 12 DSB 11 DSB 10 DSB 09 DSB 08 DSB 07 DSB 06 DSB 05 DSB 04 DSB 03 DSB 02 DSB 01 DSB 00 - IDLE [IDL] WT Gate Not in ER RO? Header Not in ER DRE Drive Error OVR Overrun WLO Write Lock Out Violation SKE Seek Error PGE Programming Error NXM Non-Existent Memory DLT Data Late RTE TE Timing Error NXD Non-Existent Disk NXC Non-Existent Cylinder NXS Non-Existent Sector - - - CSE Checksum Error WCE Write Check Error PREAMBLE [PRE] HEADER [HDR] DATA [DAT] CHECK [CHK] POSTAMBLE [PA] - IWC 7 IWC 6 IWC 5 IWC 4 IWC 3 IWC 2 IWC 1 IWC 0 BC 3 BC 2 BC 1 BC 0