Wanted: Exidy Sorcerer CP/M

[dutchacorn]

Were there any harddisk systems for the Exidy ? Preferably with some info on IO addresses and/or controller so I can add it to my ARM Exidy emu.
I find that little over 300k per floppydisk can be tight assembling large sources, because of the generated PRN file.

I was thinking that that would theoretically be possible as there were S-100 based hard disk interfaces. And a fast google gave me this: https://vintagecomputer.ca/exidy-sor...ystery-solved/

[Witchy]

Nope, mine is soft sectored.

More reading and actually examining my floppies shows they're very definitely hard sectored. I've never seen hard sectored 5.25" disks before so this is interesting indeed.

[Chuck(G)]

I find that little over 300k per floppydisk can be tight assembling large sources, because of the generated PRN file.

The usual procedure with two SSSD 8" floppies (250KB per) was to assemble without without a listing to check for errors and getting binaries and then to assemble a second time with an online printer. Vast piles of software were developed using only two 250K floppy drives. Hard drives were either freakishly expensive or simply not available during the early days of 8-bit computing. I think the hard disk for the Intel MDS800 had a 5-digit price tag (and that was when a dollar was worth considerably more than it is today).

[exidyboy]

Micropolis metafloppy

That by far seems to be the most common drive around.
There is one up on eBay right now with a couple of Exidy floppies w/o the S-100 card
https://www.ebay.com/itm/Vintage-Mic...e/292576089404

but it's too expensive to get at couple of single-sided 100tpi drives ($569)

We appear to have copies in the CHM collection of the floppies that are there
We also appear to have four or five of them in the hardware collection along with the controllers that appear to have been
connected either to Sorcerers or Sols

I may be able to negotiate access to disks containing CP/M 2.2 for the Exidy FDS - an exciting find. Al do you already have CP/M 2.2 disks (but un-imaged?).

Also what is the process to image a single-sided 77 track 5.25 inch floppy - do I need the actual drive or can I use a more modern drive and if the former what would I hook it up to?Exidy_FDS_CPM22.jpgExidy_FDS_operators_manual_cover.jpg

[dutchacorn]

A few months ago I managed to get a (dual) DP-6400, including working CP/M disks (also 2.2). So that is 40 tracks, not 77 tracks.

The 77 tracks disks are 100 TPI, more modern drives are 96 TPI. It may be a challenge to read these on a later disk drive?

[Chuck(G)]

You need a 100 tpi disk drive to do it correctly. The 100 tpi and 96 tpi drives do not place track 0 in the same spot--and of course, the track spacing is different. So even if you were bang on at track 0, you would be several tracks off by track 77.

I suppose that if you were very mechanically handy, you might be able to turn (as in a lathe) down the size of the positioner hub on a taut-band unit slightly to accommodate the difference, but that would be a very touchy operation. Other 100 tpi drives, such as those from Micropolis, used different leadscrews to handle the spacing difference.

Another possiblitiy would be to modify the firmware in a Drivetek/Kodak drive to handle 100 tpi spacing, but that would be a tough task without any firmware source--and the Drivetek drives are probably harder to find than old 100 tpi units.

Generally, it's easier to replace 100 tpi drives with 96 tpi ones and copy data over to the more common format.

[dutchacorn]

If you are lucky the drive is fitted with a “floppy disk subsystem add-on”. It would have a cable to connect a second unit:

97C7706B-7D13-47BA-91FC-69AE006D531B.jpg

You should then be able to connect a 80T 96TPI drive as a second drive and copy cpm 2.2 to that.

[exidyboy]

Generally, it's easier to replace 100 tpi drives with 96 tpi ones and copy data over to the more common format.

Yes most active users here in Oz who hung onto their machines and continued to use them moved onto more standard 720K drives and one of several locally developed FDC's.

Although the system is interstate I will be able to get access to the drive eventually but is it going to look like sufficiently like a normal drive to be connected to the Shughart connector of PC floppy interface, Kryoflux etc and imaged using one of the conventional approaches?
Exidy_FDS_micropolis_1015_internal.jpgExidy_micropolis_1015_board.jpgExidy_FDS_rear.jpg

[exidyboy]

If you are lucky the drive is fitted with a “floppy disk subsystem add-on”. It would have a cable to connect a second unit:

97C7706B-7D13-47BA-91FC-69AE006D531B.jpg

You should then be able to connect a 80T 96TPI drive as a second drive and copy cpm 2.2 to that.

Do you know if Exidy FDS controller supports anything other than the Micropolis 1015 100TPI drives that Exidy supplied in those few years that they were in the personal computer game.

[dutchacorn]

There were two variants as far as I know:
DP6400: 40 Tracks, 48 TPI
DP6402: 77 Tracks, 100 TPI

CD966454-1BD2-46F7-A717-018FE0C0AF85.jpg

The add-on units for a second drive (no controller) were DP6401 and DP6403 for 40 tracks and 77 tracks respectively.

I would expect the controller to be able to handle 80 Tracks / 96 TPI.

I once hooked up a 100 TPI drive to my Acorn BBC and that worked fine (obviously rhe formated disks could only be read in the 100 TPI drive). So I expect you’d be able to use the 100 TPI drive with a Kryoflux.