I did some basic diagnostics on the system. First, checked the superficial stuff like the cable. The Berg has a strain relief attached and all wiring looks solid at that end. Also checked the head lock which was indeed in the lower (free) position however I observed the head suring loading and it does indeed retract properly ... when the LOAD key is out the heads retract immediately to the parked (fully retracted) position. When a fault occurs, heads pull back as well. True, the unit was transported without the head lock in place - any ideas on possible misalignments? When the BOOT switch on the limited-function panel (or the BOOT key on the console) is pressed, the FAULT light blinks momentarily, the READY light goes out momentarily, and the disk is restored to the original, ready, state. When the cartridge is loaded, the heads move from the parked state to engage the disk. During the fault the heads pull back to the parked state and are then restored to the disk again. When the bootstrap is stepped, the READY light never does blink (stays lt), nor does the FAULT light! Which leads me to wonder why? Checked the ROMs on the 8317 board - they are labelled '469A2' which I can't seem to track. Bootstrap option switches are set as SW1: 2,4,8 ON, SW2: 1,6 ON so with the older ROMs one would expect a TA8-E device (obviously different or these ROMs). Can I verify the bootstrap code easily? Now, when I do step-through the bootstrap I have loaded (at address 1 - the one on my web page), the address is seen to step through as follows: 1,2,3,27,30 (with AC=0004), 31,33,34,27,4,5,27,30,31,33,35,1 at whch point it repeats in an endless loop. It seems to fail, then, on the read header function (at which point I did the diagnostics I had outlined finding the DCRC error after which I did a get status. I'd be grateful for any further ideas you might have on the subject otherwise it might well be 'get out the scope' time! Thanks .... Mark Professor Mark Csele Niagara College, Canada 300 Woodlawn Rd., L-8 Welland, ON, L3C 7L3 (905) 735-2211 x.7629 E-Mail: mcsele at niagarac.on.ca URL: http://technology.niagarac.on.ca/people/mcsele Author of "Fundamentals of Light Sources and Lasers", Wiley, 2004