> On Mar 9, 2021, at 8:32 PM, Chris Zach via cctalk <cctalk@classiccmp.org>
> wrote:
>
>> Really? The very similar RS64, as well as the RS11, both had a formatter
>> device that field service could use to write the timing tracks if they were
>> lost. Or, for that matter, if the platter had to be replaced, since it
>> arrived from the factory totally blank.
>
> Oh, sorry, meant the data was lost. I don't think it had the formatter on the
> unit though.
Right, the formatter was a piece of field service hardware. I think typically
it had to be shipped up from Maynard, there wasn't enough call for them to have
them at each field office.
One oddity is that the timing track clock frequency on those writers is
variable. The device would write the correct number of timing pulses and then
read the timing track to verify the length of the gap at the end. Lights would
indicate whether the gap was too small, correct, or too long, and you'd adjust
the frequency knob accordingly until the "ok" light came on. It's documented
in the maintenance manual. I read it long before I saw it done, and was amazed
that yes, it actually work just as strangely as what the manual claims.
Judging by the block diagram in the manual, you could build your own in an
afternoon or two.
>> Sure, a generalization of Dave Gesswein's MFM emulator. I was just looking
>> the other day how practical it would be for such a device to do an RK05
>> emulation. The answer seems to be: quite practical.
>
> The MFM emulator is an amazing bit of kit.
It certainly is. It works wonderfully well.
paul
