Robert J. Stevens wrote:
> I am looking for some DIP 14 150 Ohm Resistor PACKs for my Shugart 851
> DSDD Diskette drive.
> I hope someone has a spare or two in their Parts Box
> TIA
> Bob in Wisconsin
> USE
> trebor72@execpc.com

Hello Bob,


I don't have any of these.
I did a quick WWW search but the places I found that sold DIP
resistor networks didn't have 150 ohms. It should be fairly easy to make
some. I checked the SA850 series manuals at BitSavers and it shows that
the resistors are just placed across short dimension of the pack. So I
have two suggestions as to how to make some.

1) Buy 14 pin DIP headers and some resistors and solder them in place.

Resistors, 150 ohm, 1/4 watt. Jameco 30163, pk of 100, $1.05
DIP header, 14 pin, Jameco 291312, $1.55 ea.
Available at www.jameco.com

2) Buy two of the 330 ohm DIP resistor packs available at several
places and solder one carefully on top of another. This will
give a resistance of 165 ohms which is not too far from 150 ohm.
Jameco 291312 is a 16 pin 330 ohm DIP for $.39 ea. You could cut
the two pins at one end off and if nothing else is in the way it
might fit.

Of course other places might have the 14 pin version.

Jeffrey W. Shook

Jeffrey W. Shook wrote:
> Robert J. Stevens wrote:
>> I am looking for some DIP 14 150 Ohm Resistor PACKs for my Shugart
>> 851 DSDD Diskette drive.
>> I hope someone has a spare or two in their Parts Box
>> TIA
>> Bob in Wisconsin
>> USE
>> trebor72@execpc.com
>
> Hello Bob,
>
> I don't have any of these.
> I did a quick WWW search but the places I found that sold DIP
> resistor networks didn't have 150 ohms. It should be fairly easy to
> make some. I checked the SA850 series manuals at BitSavers and it
> shows that the resistors are just placed across short dimension of the
> pack. So I
> have two suggestions as to how to make some.
>
> 1) Buy 14 pin DIP headers and some resistors and solder them in place.
>
> Resistors, 150 ohm, 1/4 watt. Jameco 30163, pk of 100, $1.05
> DIP header, 14 pin, Jameco 291312, $1.55 ea.
> Available at www.jameco.com
>
> 2) Buy two of the 330 ohm DIP resistor packs available at several
> places and solder one carefully on top of another. This will
> give a resistance of 165 ohms which is not too far from 150 ohm.
> Jameco 291312 is a 16 pin 330 ohm DIP for $.39 ea. You could cut
> the two pins at one end off and if nothing else is in the way it
> might fit.
> Of course other places might have the 14 pin version.
> Jeffrey W. Shook
I found an E-Bay Auction for some 150 Ohm 1/8 Watt metal film Resistors
and am getting some 14 Pin DIP Component Carriers from JDR and that
ought to do the trick.
Thanks
Bob

Robert J. Stevens wrote:

>>> I am looking for some DIP 14 150 Ohm Resistor PACKs for my Shugart
>>> 851 DSDD Diskette drive.
>>> I hope someone has a spare or two in their Parts Box

The SCSI termination standard uses 110 Ohm resistor packs. Anyone know if
this is "close enough" for terminating floppy drives? Seems like it would
work the line drivers a bit harder, but am curious whether it's likely to
damage anything.

Steve

Steven Hirsch wrote:
(snip)

> The SCSI termination standard uses 110 Ohm resistor packs. Anyone know
> if this is "close enough" for terminating floppy drives? Seems like it
> would work the line drivers a bit harder, but am curious whether it's
> likely to damage anything.

The usual SCSI termination is 330 ohms to ground, 220 ohms to +5,
which results in, if I have it rights, 132 ohms to +3V.
Some systems might use a 3V power supply and 132 ohm resistors.

110 or 132 are probably close enough for floppy termination.
(Especially since it is the same cable used for SCSI.)

-- glen