Test Diablo Model 31 drive and disk pack on a PC (Operation Alto

If I rememebr the Model 30 (which is very similar) correctly, it does not need the cotnroller to go ready. It's a good idea to haev the terminator fitted, though, I seem ot remember that on some drive the write gate line can become asserted if it floats, leading to a corrupted disk. For the same reason, if you don't have the controller boards fitted or powerred, it's a good idea to unpluy the controller cable from the drive. I seem to rememebr that. at power on, the Model 30 notices it;'s not getting any index pulses from the (non-existant) disk, and after some seconds it wil lunlock the front door. At this point you can open the door and slide in the disk pack. Then close the door and press the appropriate button. The disk should then spin up, and when the drive thinks it's u to speed, it will load the heads. The Modle 30 is odd here i nthat this is not done my moving theh eads from the home position towards the spindle and thus having the heads come off a ramp. Istead there is a load solenoid on the side of the positioner which is energised. Now, since thrre is no sync/servo information read from the disk iself, the drive will go ready id the disk is totally blank, or if there's a problem with the heads or read/write electronics. Now what I would do is temporarily disconnect the load solenoid. Then power up, insert the pack and spin up. The heads then can't load, but thr disk should spin up, and the drive go ready. If it does, and the spindle seems to be spinning properly, then you can power down, reconnect the solenoid and try it for real (and hope you don't get a headcrash.) IIRC, these are 'midget flange' bulbs and are not easy to get. Last time I needed one, to put in an HP59306 relay actuator, actually, I repaired the old one (!). I could easily get wire-ended bulbs of the correct electrical rating, so I desoldered the connections on the cap of the defelctive midget flange blub, wrapped it in paper and crushed the glass with pliers, then cleaned out the base cap. Inserted the wire-ended bulb and soldered the wires ot the base contact and the cap. I don;t think you will get any seeking without having the controller working. Are you talking about the LOAD button on the Alto here? -tony