On Mon, Feb 13, 2017 at 10:54 AM, Rob Clarke <email@example.com> wrote: > Thanks Ethan, I have no other 8" drives other than this one, and only 2 > disks of unknown status. That does make it harder. > Yes, I've considered writing such a program to step the drive etc, but as > the ROM of the 8280 is not documented and is AFAIK, unique in using a WD > FD1797B-02 controller, I simply don't know how without a large amount of > effort to disassemble the ROMS. 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. >> In case there is a problem with the heads, is the drive mech of a type >> that can be tested on another platform? (Tandon TM848, for example, >> which the photo resembles) 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. 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. 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. -ethan Message was sent through the cbm-hackers mailing listReceived on 2017-02-13 17:01:57
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