[vcf-midatlantic] Correction -- Semi-OT: Annual post: what tech did ya get?

David Gesswein djg at pdp8online.com
Tue Dec 26 12:52:52 EST 2017

On Tue, Dec 26, 2017 at 11:28:42AM -0500, Neil Cherry via vcf-midatlantic wrote:
> On 12/26/2017 10:20 AM, Joseph Oprysko via vcf-midatlantic wrote:
> >Dave???s MFM Emulators work well, I remember when I exhibited one at VCF,
> >while a bit confusing to use, no pretty GUI or anything like that, it does
> >what it needs to do. I had tested it and duplicated an existing hard drive,
> >and created several ???blank??? hard drives over my time with it.
> MFM emulator, this means it can emulate hard drives like those inside the
> 3B1 & 3B2 or earlier drives? Were the early PC drives the same?
Yes it works with 3B1 and 3B2. http://www.pdp8online.com/mfm/

It works for systems using the ST-506 or ST-412 style interface (the
34 and 20 pin cables). The drives are pretty similar but the controllers
are not. I currently have 34 different formats it can decode.
I don't have support for RLL encoding, only MFM. May get to RLL sometime.
The DREM unit support RLL emulation. 
ESDI drives look similar but it is an entirly different interface that I also
don't support.

I may be able to support the earlier 8" SA1000 drives with adapter
but the drive I have (Quantum Q2040) doesn't have the electronics board and 
I don't have any computer with that interface to test with.

> BTW, found the missing Xebec interface card. I think this to allow those
> earlier drives to interface to SASI (early SCSI). I have no idea if it works.
I have one of those in my TI professional. The seeker expansion board we
put in it had SASI but SASI drives were very expensive. We got a good deal
on the Xebec controller and a 10 Meg hard drive. I think it was from
someone in the TI users group and the drive was used. 

> >Unfortunately this year, I didn???t get anything vintage related.
Nothing for me either.

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