Read Errors - AMSTRAD CPC464 User Manual

You will quickly lose track of your programs if you don' t give them names that will remind you of
their content - and you are advised to add some date code to the name so that you can tell which are
the most recent updates of your programs and data files.
You can CATalogue the contents of a cassette by entering the command CAT, and following the
instructions:
Press PLAY then any key:
BASIC will now list the contents of the tape, returning all file names as UPPER CASE, followed by
the number of blocks present, and then a single character that tells you what sort of file it is:
$ is a standard BASIC program
% is a protected BASIC program
* is an ASCII text file
& is a binary file
An Ok at the end of the line indicates that file is readable, and would have loaded had the computer
been requested to do so. Performing the
computer' s memory..

2.7 Read errors

If you get the message displayed that a Read error has occured while the CPC464 has been trying to
load a program or data from the cassette, then the tape will continue to play, and the computer will
continue to read the blocks that it finds after the error - except that it will not attempt to LOAD
them unless they are identified as being block 1 of the program it first tried to load (unsuccessfully).
This means that after a read error, you can stop the tape using the cassette
[REW]ind the tape to the beginning, and press
try at loading the program in which it found the read error - and with luck, this time you will be
successful.
Read errors arise from a number of causes - the most common of which is accidental damage to the
cassette tape through creasing, stretching or other afflictions of the recording surface. They can also
arise from the apparently innocent practise of switching off the computer whilst the cassette
key or the and
[REC]
This is because when the key is pressed down, the tape is held up against the tape head, and a brief
pulse of electricity can pass through this record/replay head as the power supply discharges itself.
Even though the tape itself has remained static – this ' switch off pulse' (and also the switch on pulse)
can effectively scramble the information in that part of the tape, and make it unreadable.
Furthermore, the stationary tape is held tightly between the capstan and pinch roller, which, if
greatly prolonged, can lead to tape creasing.
Read errors can also occur if the tape was [PAUSE]d during the record or play Process, or if it has
been originally recorded on another CPC464 where the tape heads are incorrectly aligned.
CAT
keys are still pressed down.
[PLAY]
function will not affect the program currently in the
again. The computer will then have another
[PLAY]
key,
[STOP/EJECT]
[PLAY]