3.5" floppy jumpers

[Tony Duell]

> 
> On 28/11/2008 04:39, Curtis H. Wilbar Jr. wrote:
> 
> > Another is a TEAC FD-235HF and has jumpers for: H HO, OP, LHI, HHI,
> > and a position (but no header pins) for FG.
> 
> See if Google can find you a document called 3fd0020a.pdf -- that's 
> TEAC's config sheeet for the whole FD235 range.  There are lots of 

One annoying thing about Teac is that they don't put a description of the 
jumpers in the service manual (I have several such manuals for drives 
that I own). Why not, I don't know.
> > The last is a Sony MPF520-1 which has 2 rows of 3 pins... and I have
> > no idea what they are for.
> > 
> > I understand some abbreviations... RDY (ready), DC (disk change),
> > but not MD, MM, TTL/C-MOS (assuming this is for interface logic
> > levels?), and the TEAC ones I don't know at all.
> 
> MD and MM usually refer to what turns the motor on: only when asserted 
> with Drive Select, or any time the Motor On signal is active.
> 
> > The Sony one is a mystery, and a google search hasn't turned
> > anything up... don't know if the headers are for selecting D0-D3
> > only... or more than that.
> 
> Some Sony drives have jumpers to determine when they output index pulses 
> (only when the drive is up top speed, or always).  But if you only have 
> a few, they're probably just the drive select jumpers.


In a case lioke that I'd 'buzz out' (test for continuity using the beeper 
function of a DMM or whatever) any connections between the jumper pins 
(all lnks removed , but note where they were!) and the interface 
connector pins. If you find pins that go, say, to the DSn pins, it's a 
fair bet they're for drive selection. If it goes to pin 2, it's probably 
soemthing to do with density selection. Pin 34, and it's ready/disk 
change. That may at least identify some of them.

-tony