Kaypro: 81-149C vs. 81-232

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Sun Mar 29 05:04:09 1998

On Mon, 23 Mar 1998, Tony Duell wrote:

> > At the back of the main circuit board, just in front of where the ribbon
> > cable connects to it, there is a 14-pin chip with a label "1F" beside it.
> > In drive A, there is an empty 16-pin socket beside it, with "2F" written
> > on the circuit board beside it. Drive B has something IN this socket - a
> > BLUE 16-pin chip.
>
> Sounds a little like a Tandon drive, although those normally had the
> jumper in location 1E (or at least the schematics I have show it there).

I believe it is a Tandon drive.

I am unable to view the main circuit boards of the drives because they're
in a metal box, but if 1E is directly in front of 2E, then yes, I believe
I'll find the jumpers there. I've found labeled photographs of a Tandon
drive in an old issue of 80 Micro.

<snip>

> The 14 pin 'chip' is the jumper pack. Alas the schematics I've found show
> a _16_ pin jumper at location 1E with the following functions :
> 1-16 Enable head load on drive selected
> 2-15 Drive select 0
> 3-14 DS1
> 4-13 DS2
> 5-12 DS3
> 6-11 Mux (drive _always_ enabled)
> 7-10 Not used
> 8-9 Eanable head load on motor on

The photos show a 16-pin socket, filled with a 14-pin "DIP shunt", with
only four switches in it, corresponding (I think) to DS0-DS3.

> I've also found a later version of the drive with a 14 pin jumper at
> location 'U8'. It has the following functions
> 1-14 Enable head load on drive selected
> 2-13 Drive select 0
> 3-12 DS1
> 4-11 DS2
> 5-10 Mux (drive _always_ enabled)
> 6-9 DS3
> 7-8 Eanable head load on motor on

How similar in appearance are these two drives? The one in 80 Micro (#56,
Sept. 84) appears identical to the drives I have, at least as far as my
limited viewing window allows me to see.

At any rate, once I manage to remove the drives from their housing, I'll
find the jumper blocks.

<snip>

> There are 3 common '6-sided' screwdrivers :
>
> Allen hex - a true hexagonal tip, which come in inch and metric sizes

This is the one I need. Possibly in metric sizes as none of the imperial
ones I have fit.

> Torx - looks like a 6-cycle 'sine wave' wrapped around a circle. This one
> is common in computer equipment

And quite annoying. :)

> Bristol Spine - has 6 _square_ splines (sometimes only 4). This one is
> common in Friden machines, and in some IBM stuff.

I don't think I've ever seen this one.

Thanks again!


Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Sun Mar 29 1998 - 05:04:09 BST