WTB: HP-85 16k RAM Module and HPIB Floppy Drive

Paul Berger phb.hfx at gmail.com
Fri Nov 17 11:26:05 CST 2017

I just checked my 9122C I happen to have open and the interval between 
index pulses is 199.66mS  which would be 300 RPM, which is good news for 
me I can now proceed with adapting a more common 1.44 drive to replace 
my broken one.


On 2017-11-17 1:04 PM, Eric Schlaepfer via cctalk wrote:
> Check your email. How can you tell if it uses a 600 RPM mechanism or not?
> On Thu, Nov 16, 2017 at 3:17 AM, Eric Smith <spacewar at gmail.com> wrote:
>> Hi Eric,
>> It's not urgent, but when you have a chance, could you dump the 9122C
>> ROM(s) and take high resolution photos of the controller board?
>> Since it does HD, I suspect it probably does not use a 600 RPM mechanism.
>> Thanks!
>> Best regards,
>> Eric
>> On Nov 15, 2017 17:45, "Eric Schlaepfer via cctalk" <cctalk at classiccmp.org>
>> wrote:
>>> It'd be interesting to find out how well that PRM-85 works. I've laid out
>>> a
>>> board for a rough equivalent but I haven't fabbed it out. It may be
>>> cheaper
>>> for me to buy that instead.
>>> I've also got a 9122C but I don't have the mass storage ROM so I can't use
>>> it with my 85. Right now I'm using it with my 9000 series 300.
>>> On Tue, Nov 14, 2017 at 8:26 PM, Mark J. Blair via cctalk <
>>> cctalk at classiccmp.org> wrote:
>>>>> On Nov 14, 2017, at 20:11, Ed Sharpe via cctalk <
>>> cctalk at classiccmp.org>
>>>> wrote:
>>>>> wondervifcthec9122 drives,will work on 85?
>>>> I think I can guess what you meant to say there... :)
>>>> I’ve ordered a PRM-85 (a modern reprogrammable ROM drawer replacement)
>>>> which includes the HP-85B version of the Mass Storage ROM, and the
>>> Extended
>>>> Mass Storage ROM. Based on what I have read, I think that should let my
>>> A
>>>> model use the newer 9122C drive, and other drives using either the
>>> Amigo or
>>>> SS-80 protocols.
>>>> I’d like to get the 9122C mostly because I have a much easier time
>>> finding
>>>> 1.44M media than the older double density media. eBay and I don’t talk,
>>> so
>>>> that limits my options a bit. If I had easy access to lots of 3.5” DD
>>>> media, then I would consider getting one of the more plentiful (?) other
>>>> 3.5” HPIB floppy drives.

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