[Coco] tandy 1000 ex/hx external drive

Bill Pierce ooogalapasooo at aol.com
Fri Aug 29 17:38:37 EDT 2014


On further note to what I replied before on the EX drive, here is a letter and answer printed in the July 99 issue of Rainbow in the "Coco Consultations" section:


----------
The letter:
Strange Connector
What is involved in using one of those Tandy 1000 EX external add-on drives with a Color Computer? It uses a funny 30-pin connector on its cable.
Dick Reitz
New Jersey


The Answer:
The drives and cases with those Tandy external drive systems are excellent generic items that can be used with the CoCo and other computers. However, the 30-wire cable that comes out of them is ultraweird and very specific to the Tandy 1000 computer system. The cases have no power supply in them, and power is supplied to the drive via some of the lines on that 30-wire cable. The data and ground lines for the drive are in totally different places on the cable than they are in normal 34-wire drive cables. My recommendation, if you have such a drive and want to use it with the CoCo, is to open up the case and remove the Tandy special cable, then use your own normal 34-wire cable and add a power supply of your choosing to the system. Paul Tesch (PAUL TESCH) told me he checked the 30-wire cable using an ohmeter, and got the results shown in Table 1.
---------


Table 1.
Tandy 30 pin cable - Normal 34 pin cable (and/or power supply)
1                             +12v
2                             +5v
3                             +12v
4                             +5v
5                             GRND
6                             +5v
7                             GRND
8                             +5v
9                             GRND
10                           Pin 8
11                           GRND
12                           Pin 26
13                           GRND
14                           Pin 20
15                           Pin 32
16                           Pin 16
17                           Pin 18
18                           GRND
19                           Pin 28
20                           GRND
21                           Pin 30
22                           GRND
23                           Pin 22
24                           GRND
25                           Pin 24
26                           GRND
27                           Pin 10
28                           +12v
29                           Pin 12
30                           +12v


This table shows how the special 1000 EX cable connects to a standard (Coco) cable and is really of no use.
It seems my earlier message about the adapter plate was right and that the 30 pin cable went into the unit and was then split off to the drive connector and power plug on the adapter plate.
So, according to this article, all one should have to do is open the unit, disconnect the 30 pin cable and you should have a standard 34 pin header and 4 pin molex left to deal with which is standard on Coco drives. This drive can be removed from this case and easily installed in a Coco drive case with no modifcations. Also, the actual drive can be removed from the plate and the plate used for other 720k drives.
I have one mounted in one of my drive cases :-)






Bill Pierce
"Today is a good day... I woke up" - Ritchie Havens
 

My Music from the Tandy/Radio Shack Color Computer 2 & 3 
https://sites.google.com/site/dabarnstudio/
Co-Webmaster of The TRS-80 Color Computer Archive
http://www.colorcomputerarchive.com/
Co-Contributor, Co-Editor for CocoPedia
http://www.cocopedia.com/wiki/index.php/Main_Page
E-Mail: ooogalapasooo at aol.com




-----Original Message-----
From: Bill Pierce via Coco <coco at maltedmedia.com>
To: coco <coco at maltedmedia.com>
Sent: Wed, Aug 27, 2014 10:47 am
Subject: Re: [Coco] tandy 1000 ex/hx external drive



 have one of those "EX/HX" drives that a friend gave me years ago. He had 
onverted it to the Coco already when I got it. It's the one RS sold that was a 
mall white case with no PS, just a drive in the case.
is method was to use a "standard" Coco drive cable and PS cable extender.
y drive has a mounting plate in it (5.25 to 3.5) with a 5.25 drive cable end to 
.5 end and the same is done for the PS. This plate can be removed and mounted 
n a standard Coco double drive case as well (where mine resides now). I have no 
lue where he got the mounting plate or if it was in the drive already.
 have come to cherrish that mounting plate as it allows me to use any 720k 3.5 
rive with my Coco drive system (as long as it has jumpers). I keep the original 
ase just in case I want to re-mount it someday, but for now, I like it in my 
oco drive case.
f I get a chance, I'll post some pictures of it.

Bill Pierce
Today is a good day... I woke up" - Ritchie Havens

My Music from the Tandy/Radio Shack Color Computer 2 & 3 
ttps://sites.google.com/site/dabarnstudio/
o-Webmaster of The TRS-80 Color Computer Archive
ttp://www.colorcomputerarchive.com/
o-Contributor, Co-Editor for CocoPedia
ttp://www.cocopedia.com/wiki/index.php/Main_Page
-Mail: ooogalapasooo at aol.com


----Original Message-----
rom: Frank Swygert <farna at att.net>
o: coco <coco at maltedmedia.com>
ent: Wed, Aug 27, 2014 9:55 am
ubject: Re: [Coco] tandy 1000 ex/hx external drive

ate: Mon, 25 Aug 2014 02:43:22 -0400
om: Al Hartman<alhartman6 at optonline.net>
 have a  tandy 1000 ex/hx  external  disk drive  does anyone know  how
can power this so I can use it on the coco
--------------------
hat drive has power fed to it over the drive cable, IIRC through two of the 
nes normally grounded. What you'll have to do is open the drive case, find the 
wer connector (should be a regular connector with wires jumped over to the 
ive data cable), cut them, then use a wall wart to feed it power. It may be a 
V only drive. If so a single 5VDC wall wart will work. If it needs +12V you'll 
ve to use a pair of warts -- one with 12VDC also. That is the easiest way to 
wer it. You can use any +5V/+12V power supply. If you check the surplus 
mpanies (http://www.allelectronics.com/, http://www.alltronics.com/) you can 
nd power suitable switching supplies.
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