Thanks Mike. I have a Teac FD-55B-01-U on the way, which should be 360k.
I also found another disk in the packing materials for my dvi. It doesn't boot either but it looks like it is also a system disk, even though the two disks look different and have different catalog numbers. https://photos.app.goo.gl/iyQgkHnuj55Is23t2 -- bkw On Oct 28, 2017 8:48 PM, "Mike Stein" <[email protected]> wrote: At a fast glance through the sparse documentation available it doesn't look like any of those drives will do. Again, there's some confusing terminology here; I don't think Epson's dual density is the same thing as double density and I think they're actually talking about track density. There are three (formatted) possibilities: 1.2 MB 96 tracks per inch, 500kbps 740KB 96 tracks per inch, 250kbps 360KB 48 tracks per inch, 250kbps. 740KB (sometimes called quad density) was not very common and Epson probably means that their drive is only capable of two densities, 1.2MB HD and 360KB DD as used in PCs and clones. The DVI disks are single-sided double density, with the same capacity as a single-sided DD PC diskette but arranged as 40 tracks of 18 256 byte sectors instead of 40 tracks of 9 512 byte sectors. The number and size of sectors is a function of the controller, so the DVI drive is the same as one side of a standard 360K DD drive as used in PCs and elsewhere. To read a DD diskette in an HD drive you need to slow it down from 360 RPM to 300 RPM (or adjust the transfer rate) and you have to take two 80 TPI steps for every 40 TPI step. It looks like an 'I' jumper on the Teac 505 should make 300RPM available, and pin 2 would then enable it; unfortunately there's no indication that it (or any of these drives) are capable of double-stepping, leaving that up to the controller. But I could be wrong... m ----- Original Message ----- *From:* Brian White <[email protected]> *To:* [email protected] *Sent:* Saturday, October 28, 2017 4:09 PM *Subject:* Re: [M100] DVI cable On Oct 28, 2017 1:00 PM, "MikeS" <[email protected]> wrote: What's the make/model of the HD drive? Might be trivial to configure it to read a DD diskette. Epson SD-680L Epson SD-600 combo Teac FD-505 combo And on the way in, Epson SD-521 The SD-680L looks nice and configurable, although this pdf suggests it's not fully configurable, but maybe that just means it can't do *single* density? http://jope.fi/drives/40200A03.pdf Easy enough to try, so I will do that next. Do you only have one system disk? Yeah just the one. Looks original. Factory label that says Model 100 Disk Operating System. Obviously I intended to make copies and only use the copies, if it worked at least once. Maybe it still will work in a different drive. Or I might possibly be able to use those disk images that Steven put up on club100 to make a new disk from scratch. One of my old servers might possibly have a floppy controller that would work. That would be a whole project of it's own, since everything probably has bad caps. Otherwise I'm hoping one of you gents would be willing to let me mail you a few blank disks and you run the backup util to make a couple copies? -- bkw
