More "operator error". Sometimes I think I have mild dyslexia. The RL02 Fault and Ready lights stayed on which is usually a sign of bad cabling (lost clock). Although I had carefully aligned the IDC connectors while making my substitute RL02 ribbon cable, I thought I'd save some effort by using a 40 pin header as a male-male connector directly to the Berg connector (that mates with the drive bulkhead connector inside). However - after considerable schematic, DVM and scope work I belatedly discovered that this connects the headers in a mirror image and although left/right can be swapped by turning over the ribbon cable, the two rows are now swapped as well! The four corner pins are 3 grounds and the BPOK H signal. Wrong cabling doesn't hurt anything on the RL8E since the power-ok circuit has a 100 ohm resistor in the collector of the driver transistor. But on the RLV12 there is no protective current limiting and the PNP transistor (MPS-A55) is turned on hard between +5 and the (short to) ground! Fortunately it just got hot but didn't fry, although it might if it'd taken me much longer to figure out the trouble :) Anyhow this time when I powered up there were no lamps lit on the RL02 (normal) and after the requisite 15 sec. powerup the Load light came on. I crossed my fingers and pushed the Load button and the drive spun up and the Ready lamp lit. So far so good. So I flipped the restart switch on the CPU, answered "Y" to "Start?" and got a message "Please boot from system disk". I have one other disk pack that is known to have come from a PDP-11, so I put it in the drive - lo and behold, "Booting up XXDP-XM Extended Monitor" followed by ... "V2.4, Rev. E1, booted from DL0, 124Kw memory, Non-Unibus system, restart address 152000, type H for help". Looks like I now have a working PDP-11 :) The pack has 727 files on it whose names are meaningless (to me anyway). XXDPXM.SYS etc. is obvious but there are hundreds of files from A to Z with names like "VKMHA0.BIN", "ZAFAC0.BIC" and some .LIB and .OBJ files too. What on earth do I have here? Is it something that anyone would be interested in copying? -Charles