AMSTRAD CPC464, User Manual

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Read errors will also arise from time to time for purely arbitrary reasons. The compact cassette was
not originally designed as a medium for data storage, and as such it has several shortcomings that
set it apart from the more complex and considerably more costly ‘professional’ tape storage systems.
Notwithstanding this, the cassette has performed an excellent job of providing a standard ‘medium’
for low cost computer data storage and retrieval. The limitations of the physical characteristsics of
the size of the magnetic particles on the tape surface, coupled with the speed at which the tape
passes the head places a finite limitation on the rate at which data will transfer between tape and
computer.
TO
attempt to push speeds beyond the upper tolerance of the system will cause unreliable
operation
-
particularly with mass cassette duplication methods used for manufacturing low cost
software.
NOTE
that cassettes containing programs from other types of computer cannot be read or loaded on
the CPC464. They may look the same - they may even make similar ‘sounds’ if played through an
audio cassette playback system - but they will not load and run. If you do find any that appear to
load and run - then we would be pleased to hear from you giving details of the computer type and
program concerned.
2.8 Cassette considerations
Although the Datacorder will happily accept all types of cassette up to C90, you should only use Cl2
(6 minutes per side) and C30 at the most. Programs stored at the end of long cassettes are hard to
locate unless you are prepared to wait for them to be found (and you can remember the filename you
gave them), or you are meticulous about using the tape counter in your indexing system (ie in the file
name). If you want to overwrite a program stored on a long cassette, then you must be careful to
locate the start point, and take care that you do not overwrite any other program that you may wish
to keep.
Overall, use each separate cassette for as few programs as possible. Cl2 cassettes are relatively
cheap - and should you damage the tape for any reason, it’s considerably less tempting to want to
save a cassette which is ‘good in parts’.
Finally, please remember that commercial software is nearly always supplied under strict conditions
of copyright. You should not attempt to copy or otherwise duplicate software supplied on cassette
other than in accordance with the terms of sale of that software (some programs actually encourage
you to make backup copies)
-
even if it’s ‘only for a friend’. The laws of copyright are being revised to
deal with all forms of unauthorised software duplication, and although there have been few
prosecutions to date, this situation will change substantially over the next few years, and may be
retrospectively enforcable.