3.5" floppy jumpers

Curtis H. Wilbar Jr. rescue at hawkmountain.net
Fri Nov 28 08:13:53 CST 2008

Pete Turnbull wrote:
> 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 
> models with different jumpers.  That one is one of the dual 720K/1.44M 
> 3xxx (old) versions.

Found that... doesn't cover this one (or not that I can see).

Mine has 6 jumpers, not a grid, and they are :

The specifics on this TEAC are:

DF-235HF 172-U
P/NO. 19307321-72

Read on below for some more on the Sony drive...
> HO determines whether it outputs a signal to tell the host controller 
> whether the disk is DD or HD, normally on pin 2.
> HI determines whether it accepts a density select input on pin 2.
> LHI and HHI are something to do with the density select input on pin 
> 2.  They're definitely related to HI, but I seem to recall having 
> jumpers on all three on at least one drive.  I'm pretty sure you 
> jumper both or neither, never just one.
> I'm not sure what H on its own would be.  HA tells the drive to 
> determine density itself, from the HD hole sensor, instead of getting 
> it from the host.
> Sometimes there's a number after the jumper name, like for DC.  DC34 
> means the Disk Changed signal is on pin 34, while DC2 (on a few 
> models) means it puts that signal on pin 2.
> FG is for Frame Ground; sometimes there's a jumper or solder link to 
> connect it to the 0V DC supply.
>> 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.

On the Sony one, the bottom side has silscreened for one jumper S0/S1
and the Other 3/3M.  So one is drive0/drive1, but what is the other ?

-- Curt

More information about the cctalk mailing list