Path: utzoo!mnetor!uunet!tektronix!reed!percival!bucket!leonard
From: leonard@bucket.UUCP (Leonard Erickson)
Newsgroups: comp.sys.tandy
Subject: Re: Help wanted with ancient TRS80 Model I
Message-ID: <738@bucket.UUCP>
Date: 28 Jan 88 05:46:05 GMT
References: <4480@ecsvax.UUCP>
Reply-To: leonard@bucket.UUCP (Leonard Erickson)
Distribution: na
Organization: Rick's Home Grown Unix; Portland, OR
Lines: 50
Keywords: TRS80 Model I Single Density Disk Drive Help Needed

In article <4480@ecsvax.UUCP> unbent@ecsvax.UUCP (Jay F. Rosenberg) writes:
<
<Greetings:
<     I have just come into possession of a very used TRS80 Model I.  16K 
<Level II ROMS, an Expansion Interface with an additional 32K, and a 
<26-1160 *single density* minidisk drive.  I'm having some problems with 
<the disk drive, and I was hoping someone out there could help.  One 
<problem is that I don't have any software.  Specifically, I don't have a 
<DOS.  But that's a minor problem.  The major problem is that I can't 
<figure out how to hook it up to the Expansion Interface using the cable 
<that came with the system.  Details:
<     The cable is the standard multi-connector ribbon cable that Tandy 
<provides for such things.  There's no problem at the Expansion Interface 
<end, but the connector at the *drive* end has no guide pin to guarantee 
<correct fit with the edge-card connector in the drive.  Consequently 
<there are two ways it can be mated with the drive.  I've tried them 
<both.  On the prima facie more plausible way, both the drive motor and 
<LED go on and stay on.  So I inverted the connector.  Now the drive 
<motor runs for about a second when the computer is powered up (as if it 
<were looking for a DOS, all right, and giving up when it didn't find one),
<but the LED doesn't come on.  What would settle the question of how to 
<mate cable and drive would be the pinout for the drive edge card.  (I 
<have the pinout for the Expansion Box edge card.)  Does anyone know what 
<it is, top to bottom?  Assuming that the plausible way of mating turns 
<out to be the correct way, does anyone know why the motor and LED come 
<on and stay on, and what I should do about it?  ANY advice will be 
<appreciated.

The connector at the EI end must not have ANY pins pins missing. And the
cable should exit the connector in a downward direction. Assuming this is
the "standard cable", it makes a diifference *which* of the 4 connectors
the drive is plugged into (drive select is accomplished by having ALL the
selects in the drive jumpered, and pulling pins on the connectors on the
cable!) Drive 0 is a specific *connector*, not a specific *drive*.

As for the oreintatiion of the cable on the drive, the drives were intended to
be to the left of the computer... If the LED and motor come on and *stay* on,
you have the connector upside down. Note that originally, the word TOP was
stencilled on the connectors. Also, *all* the drives use the same motor select.
So if any drive spins, they all do. 

Finally, you may still be able to buy TRSDOS 2.3 from Radio Shack for $15 or
so. If not, I can sell it to you along with a LOT of software. (But you have
to buy my  old M1 too! Say $100-200 for the works?)

-- 
Leonard Erickson		...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I used to be a hacker. Now I'm a 'microcomputer specialist'.
You know... I'd rather be a hacker."