I am a bit confused about this. I have an MicroVAX II in a BA123 enclosure with an RQDX3 which has a problem with not seeing the disks (which I know to work), when I try to boot from a disk I get DEVINACT. I am beginning to suspect a fault in either the RQDX3 or the M9058. I decided to make sure that the cable between them was the right way round as the cable I have does not have keyed connectors. Here is where I get confused. On the M9058 printset (http://bitsavers.org/pdf/dec/qbus/MP02259_RQDX3_schem_Oct85.pdf) it shows the M9058 as having pin 1 on the left of the card (when looking at the component side with J12 at the top). The printset does not show where pin 1 is on J1 of the RQDX3, but I had it connected to the uppermost side of the connector when the board was installed in its slot. In this configuration the front panel lights show green when I apply power. However this gets the error I mention above. I checked my MicroVAX II in a BA23, this machine accesses the disk just fine, but the cable is connected with pin 1 at the other side, ie opposite to the BA123. I tried inverting the cable at the RQDX3 in the BA123, but it still gets DEVINACT and this time the front panel lights don't work. I am pretty sure therefore that the cable was in the right way round in the first place, and that looking at the BA23 is a red herring, possibly with the cable being inverted at both ends and therefore "correct". Can anyone confirm that I have the cable oriented correctly in the BA123? In other words pin 1 at the bottom of the connector on the RQDX3 itself when installed in its slot, and on the M9058 pin 1 on the left of the card when viewed component side with J12 at the top (ie at the top again when the M9058 is mounted in its slot)? Thanks Rob