26 Oct
2010
26 Oct
'10
2:04 p.m.
I read in the documentation the Yellow light on the Diablo disk drive
will light up in about 45 seconds of inserting a disk, to show it is
ready to be loaded. Does this logic all happen internally in the Diablo
Disk drive, or does it require the disk interface card, or even addition
alto cards to perform this "Disk Ready" yellow light logic?
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.)
I need to replace the bulbs on the disk drive, but I am hoping if I can
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.
see the yellow light up, I know the disk drive is
somewhat functional.
Although currently, when I hit the LOAD button I do not hear/feel seeking...
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