Iomec disc drive ?

From: Bob Shannon <bshannon_at_tiac.net>
Date: Wed Dec 31 17:49:05 2003

Those are NOT DTL chips!

Your looking at CTL logic, which uses a circuit similar to an uncommited
emitter output rather than the
conventional totem-ploe output stage.

There are no drop-in replacements, and you cannot use DTL or TTL parts.

Jay Jaeger wrote:

> I have one I am working on -- attached to an HP 2114. The drive spins
> up and can seek. The interface cards in the CPU pass their
> diagnostics, but the controller is locking up -- looks like a problem
> in the state flip flops that control the early part of a command.
>
> Also, my guess is that this one is 1.2MB, not 2.5MB. It has one
> fixed platter and one removable platter. It also is exhibiting
> head/disk interference ("ting") on unload, but so far doesn't seem to
> be damaging anything when it does it (but I am using junk pack, just
> in case -- can't tell if the ting is coming from the fixed or
> removable platter).
>
> If you want to recover the data, you might consider putting the
> platter into an RK05, doing an a/d and capture of the raw data (or
> even the bit stream after recovery) from the pack. Might be safer.
>
> The logic in my IOMEC 1802 controller that is unhappy has Fairchild
> chips -- not standard 74xx fare. It may well be that they are DTL
> (sample markings on one are DT uL909759 7020), which I am currently
> guessing is a 9097 chip.
>
> Jay Jaeger
>
> At 11:11 AM 8/26/2003 -0500, Tom Uban wrote:
>
>> Hello,
>>
>> Is there any chance that someone has an Iomec removable platter
>> disk drive? The type that I am looking for uses an IBM 2315 style
>> 2.5Mb cartridge, similar to an RK05.
>>
>> I know that this is a pretty futile request, but it never hurts
>> to ask...
>>
>> --tom
>
>
> ---
> Jay R. Jaeger The Computer Collection
> cube1_at_charter.net
>
>
>
Received on Wed Dec 31 2003 - 17:49:05 GMT