13 Mar
2007
13 Mar
'07
12:54 p.m.
On 13 Mar 2007 at 13:49, Jules Richardson wrote:
Generally-speaking I suppose I can just mess around
with jumpers in the short
term if there's anything I need to change between reads for different formats;
maybe in the longer term there's a project to add parallel port control to
ImageDisk and twiddle certain bits under software control, which can then be
used to do various things :-)
Typically, one can leave the jumpers set one way for any given
installation; the only time you'll ever need to change them is for
hard- and soft-sectored operation--and then, your installation is
likely to change also.
Yes, you can disable the onboard FM separator--it's usually not the
best implementation anyway--just a couple of one-shots.
Those are less of an issue I suppose; it's just
cabling and mounting and power
routing! I'm more worried about signal incompatibilities, I suppose.
If you want to be safe, stay away from the very early models. Some
early drives require 3-phase stepper signals, for example. Some,
such as PerSci have a buffered seek and so return SEEK COMPLETE\;
some, such as the CDC BR803's don't have a READY\ line. Innovex also
has a MEDIA UNSAFE\ line. Some, such as the aforementioned-CDC,
don't use a DIRECTION\+STEP\ protocol, but rather separate STEP IN\
and STEP OUT\ lines.
As I mentioned, early Japanese drives (NEC, Mitsubishi) can be real
connundrums to puzzle out.
Tony mentioned the bit about TG43\. If you're just reading, this
doesn't matter--and some drives take care of things internally.
Stick with a late-model Shugart 850-compatible drive and you'll be
okay.
Cheers,
Chuck