On 08/20/2010 06:49 PM, KP wrote:
I have a 5 MB ProFile that recently has revived. That one is staying put. I have a 10 MB ProFile that hasn't worked in 15 years. Could be that the card is defective. Does anyone have a 10 MB ProFile interface card that they would be willing to let me borrow to test my drive with? I have an interface card that worked at one point, but either the card or the drive is now busted.
The only difference between a 5 and 10MB interface board is the EPROM. Do you have a programmer?
I have a couple of dead 10MB ProFiles here. Unlike the 5M unit, which appeared to use a standard ST506 mechanism, the 10M drive had an ST412 HDA with a different stepper motor. It required two pulses to move from track to track (not sure what Apple was thinking). So, if you drop in an ST412 you'll only have 5MB of usable capacity.
One of these days, I'm going to rig up a TTL divide-by-two circuit and see if I can get a conventional mechanism to cooperate. I think the only complexity (and it's not much of one) will be the need to recognize the Trk0 signal and clear the counter state. From that point on, it should "just work". Does anyone see a potential issue with this approach?
Steve