Hi, just a suggestion: you could adapt a 5.25" HD drive in place of the 8" just to test the controller, afair they have the same revolution speed and data rate. That said, I have a couple of boxes of 8" floppies but with unknown (to me) format and media state since I don't have any 8" drive (I whish I had). I could donate a floppy anyway. Frank On Mon, Feb 13, 2017 at 7:03 PM, Rob Clarke <email@example.com> wrote: > >> I wasn't suggesting going to that point, rather a simple BASIC program >> to do a "B-R" command for blocks on different tracks which _should_ >> cause the drive to seek, then fail as the media under the head lacked >> the correct format to produce meaningful results. So it _would_ >> "fail", but the head would at least move around. > > Good plan, I didn't think of that. I just tried it with B-R and the appears > to step up and down correctly, but of course also fails with a read error. > >> I looked into >> ftp://www.zimmers.net/pub/cbm/schematics/drives/old/8280/index.html >> It _is_ a Tandon TM-848. That is an easy one to hook up to a >> "modern" machine, and for reads, you wouldn't need a "TG43" signal >> generator (though this, from John Wilson, would take care of >> everything including 50 pin<->34 pin wiring >> http://www.dbit.com/fdadap.html) If you did pull one of the drives >> from the 8280, it could be hooked up to a PC and used as an 8" drive - >> there are formatting programs, etc., out there for such use. this >> would only get you the IBM 250K MFM format, but that's supposed to be >> supported on the 8280, so I _think_ one would do OPEN >> 15,8,15,"N0:MYDISK" to not format the media, but write out a BAM and >> directory track). A valid but admittedly intermediate test to >> formatting the whole thing. > > If I don't make progress in the immediate future, that could be a plan. > >> Oh... and since it's a dual drive, I'd also consider OPEN >> 15,8,15,"N1:MYDISK,XX" and if that failed the same way, I would >> probably proceed under the expectation that both drive mechs are >> probably not faulty in the same way. > > Yep, I swapped the mechanisms, both exhibit same behaviour. This is why I > initially thought the DOS board but now wonder if it's the media. > >> Sounds like you have someone to send you an 8280 disk so you may be >> all set, but I'd be impatient enough to at least fiddle with something >> to read blocks on different tracks just to ensure the FD1797 FDC is at >> least nominally happy. Of course that won't test read/write and data >> sep circuits or the TM848 heads, but it would test everything up to >> that point. > > And I am indeed an impatient person so will continue fiddling. I have a > couple of spare controller IC's, and all show same behaviour, so at least > that can be ruled out. > > cheers, Rob > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2017-02-13 19:02:10
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