Timex/Sinclair 1000 Tape Loading
ajp166 at bellatlantic.net
Sat Jun 18 16:26:49 CDT 2005
>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.
More information about the cctalk