Rover I portable: Does it exist?

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Thu Apr 20 08:14:44 2000

On Thu, 20 Apr 2000, Chandra Bajpai wrote:

>
> The product was called 'Exatron Stringy Floppy'...I think Exatron
> actually developed/manufactured the technology. They were advertised
> heavily in TRS-80 magazines like 80 Micro.
>
> I inherited two of the ESF drives and a lot of wafers with my last
> TRS-80....Are they that rare? Worth anything?

They are scarce with good tapes but sold well in their time. Rare, not
really.

The technology was continious loop AKA 8track carts and was an outgrowth
of modified 8track decks using shortend tapes (usually 5 minutes). with
8 data tracks that was roughly like having a 20minute tape and at 4800
that was a lot of bits. the stringyfloppy was the same save it was two
or four tracks and used narrow .140 tape (casette width) rather that the
8track sized (.250") in a very much smaller cart.

The design tricks were saturation recording (phase or NRZ), using the
splice point as index. The basic scheme was to record a header and data
not unlike floppy but at slower 2400 or 4800 baud rates. Since the tape
speed was fixed you could easily rewrite a block after the header passed
making it block replaceable like floppy. Fast forward was used to skip
blocks as a speed up. also start stop was used.

It's problem was that like most continous loop tapes the media life was
poor and there were problems with binding. I had tried 8tracks for
continous loop floppy emulation before the trs80 came out so I'd already
found out about the media problem. I went to a casette based scheme
instead.

Allison
Received on Thu Apr 20 2000 - 08:14:44 BST