Timex/Sinclair 1000 Tape Loading - test-drb@ccmp.vtda.org

18 Jun 2005

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Subject: Re: Timex/Sinclair 1000 Tape Loading
   From: Tom Jennings <tomj at wps.com>
   Date: Sat, 18 Jun 2005 14:02:17 -0700 (PDT)
     To: "General Discussion: On-Topic Posts Only" <cctech at
classiccmp.org>
     Cc: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>

On Sat, 18 Jun 2005, Gary Sparkes wrote:

  I'm having a hell of a time getting any
program to load, so far I've been
 Totally unsuccessful. 
You're having a vintage experience. This is unfortunately pretty
much how it went in 1980, only there was no mailing list for you
to gripe on :-)

Audio cassette data systems are notoriously finicky about tape
speed and volume, then cleanliness, etc.

You also have to hope that when the tapes were made, they were
with fresh batteries (or on AC adapter) and the volume was set
right, etc. It is not only possible, it was COMMON, to make tapes
that were never readable, even once.

I recall (now, with prodding, ouch) tense
rewind/play/SHIT!/rewind/play/SHIT!/... sessions with my
sole cassette-based storage system.

Actually once I got it right even with the funky MITS ACR it was 
near everytime.  After I dumped that and went to 9600 baud PE 
(Phase Encoded, fast version of tarbel and a few others). That 
and going to saturation recoding it was actually near 100%
and faster if it did fail. Storage was always never enough, 
nor fast enough. Bulk random access storage was the holy 
grail of 1975.

FYI: the funkyest device was an old audio echo drum.  It was 
1.15" high by about 9" diameter with a small AC motor and 20 
staggered heads on two tracks.  I shimmed the heads to form 
5 tracks with two heads (one for read and one for write).
The drum was coated with brown oxide and rotated at around
180 rpm (effective "tape speed of ~84ips).  I figured it 
could hold 1kb per track at around 32k baud.  It did.  
I ended up using that a for a few months (till the 
motor bearings which were poor to start failed.) to store
a whopping 10kbyts with an access time of about 400ms.

I wouldn't mind finding an old drum again.

Allison