ISO Intertec 5.25" floppy drive jumper settings

Adrian Graham binarydinosaurs at
Sun Dec 2 18:02:02 CST 2018

Hi Fred,

> On 2 Dec 2018, at 23:32, Fred Cisin via cctalk <cctalk at> wrote:
> On Sun, 2 Dec 2018, Adrian Graham via cctalk wrote:
>> In my long ongoing quest to image and otherwise copy the hard sectored floppies with my Exidy Sorcerer I’m trying to find other floppy drives I can use with it since I don’t like relying on just one set of drives. I have a Cumana dual drive set that came with my TRS80 Model1 that I thought might be jumperable to 300rpm, indeed I can see drive activity if I try and boot.
> If those were being used on a TRS80 Model1, then they are already 300RPM.

I should’ve known that.

> When they went to 400K 40 cylinder MFM DSDD / double sided, double density, still 48 tpi (like the PC-DOS 360K), they chose to call that "QD" / "QUAD DENSITY"!! ?!??   (equating "density" with capacity)
> WHOA! Everybody else called THAT DSDD "Double Sided Double Density", and used "QD" / "Quad Density" to refer to 80 cylinder Double density 96tpi!

So I’ve been reading :) I’m sure they weren’t doing it deliberately, hahaha.

> field on the sectors on the second side, but would accept disks with correct headers.
> I have heard that they used a Z80 for floppy control, but the disks are consistent with a Western Digital 179x controller.

They were always touted as twin-Z80 machines. I’ve always wanted one because when all I had at school was a Research Machines 380Z (another twin drive CP/M machine) the Superbrain LOOKED like a computer even though as I’ve been reading tonight it was originally designed as a terminal.

> I doubt that they manufactured their own disk drives, but it is possible. Look carefully at the drives for any hints of who actually made them.
> Are these "full height" (SA400) or "half height”?

You’re right. Normally with Cumana stuff I do look for a manufacturer because yes, they were known to me as makers of repackaged drives for the Acorn BBC Micro. In this case the Intertec label is a bit of a red herring and the drives are actually Tandon TM100-1 full height units. I’ve got the manual from a Rat Shack related site.

Thanks for making me look again :) 

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