13 Jan
2014
13 Jan
'14
1:55 a.m.
On 01/12/2014 05:23 PM, Terry Stewart wrote:
Chuck,
Thanks! I was hoping there would be a solution like that. I can remove a
drive from the Panasonic and use that.
Just a technical point though. What would be the correct BIOS choice to
make the PC hardware recognise the drive, as my BIOS doesn't (and probably
no PC BIOS doesn't) list an 8 inch drive. The selection is 5.25 inch 360k
or 5.25 inch 1.2MB or 3.5 inch (1.44MB)?
These Panasonic drives are double sided and 77 tracks, and the machine
write data in double density. I'm assuming this means MFM?
Yup, MFM--only a few early systems wrote in MMFM (e.g. Intel MDS)--and
they were pretty much sui generis--their scheme of address marks, etc.
wasn't the same as another vendor's MMFM (I think some HP systems used
MMFM as well).
The so-called IBM System/3 double-density uses FM on the first track and
MFM on the remainder.
If you want, you can call it a 5.25" 1.2M drive in your BIOS, but tools
such as ImageDisk don't use the BIOS anyway--it's all direct port I/O.
The only gotcha to be aware of is that many 8" drives require +24VDC for
their positioners and the like. But then, you're a TRS-80 owner as well,
right? So you should be aware of that.
--Chuck