PROGRAMS are saved to tape using SAVE CS1, and loaded back into
the computer with OLD CS1 (if you are using a tape recorder).
See also previous chapter on Cassette use and using Emulators. There is a shortage of text
on using disk files, due to the small number of disk systems sold.
The values of the program variables are not saved with the
program, and will initially have a value of zero when the program
If you wish to save a high score, or other data, you must use
file processing operations as described below.
Tape files can take a few minutes to load, but form an
inexpensive introduction for the novice programmer to the field of
data management. Fortunately, TI have provided a fairly simple
Before you can save or load data, you must 'open a file'. This
operation describes to the computer the format of the data on your
tape, and allows you to refer to the tape by a simple label,
called the file number.
When the computer comes to an OPEN statement, a section of tape
is wound on, with no signal. This is to clear any leader on the
tape. You will find it easier if you always start your data files
at the beginning of the tape, then you can be sure the computer
will find the data where it expects to.
A cassette file may be to load data or to save it, and this is
defined in the opening statement. The usual cassette operation
instructions are given when the OPEN statement is operated on.
Please keep this in mind and ensure that you do not open a file
after a complex screen display has been created!
If your printer prints a pound sign below, it means hash.CHR(35).
The OPEN statement is in the form:
OPEN #N:"CS1",INTERNAL or DISPLAY,INPUT or OUTPUT,FIXED NUM
The number N must be a number and not a variable, and lie
between 1 and 255. It is possible to have several files open at
once (eg to CS2, a printer, the speech synthesiser if using
Terminal Emulator 2 module & so on), and the file number is used
to instruct the computer which peripheral it is to use.
The choice between INTERNAL and DISPLAY is one of coding : in
DISPLAY format, the computer data is recoded to printable ASCI
code. DISPLAY format can sometimes be of advantage in DISK
processing when greater speed is sometimes possible, but for TAPE
files, it uses more tape and also requires more complex program
Using TAPE files, use the INTERNAL format.
File organisation with tape files is always SEQUENTIAL and this
word is not required in the opening statement. This means that the
second item of data read from the tape is the second item of data
which has been recorded on the tape. It is not possible to 'skip'
to say the 6th item of data without reading everything in between.
As mentioned, you MUST indicate if the file is for INPUT or
OUTPUT. You use INPUT to read data from a tape, and OUTPUT to
place data onto the tape.
You should only have one file open to CS1 at a time, otherwise
the computer will lose track of the data on the tape.
FIXED means that every time the computer writes data to the
tape, the same amount of tape is used no matter how long the data.
Any unused tape is filled with nuls. If no number follows the word
FIXED, the data field is 64 bytes long. A number always occupies 9
bytes, and a string one byte more than the string has characters.
To save data once the file has been opened, you use the PRINT
command, but add the file identification: PRINT #1:
(If your printer printed a pound one it means CHR(35) then 1.)
There is ALWAYS a colon (:) after the file number.
To save a single variable value, you would use: PRINT #1:A
To make the most of the 64 byte field length, you may save 7
variables at once, each separated in the PRINT statement by a semi
Strings are saved in a similar way:
PRINT #1:"THIS STRING IS TO BE SAVED"
If the standard field length of 64 bytes is too short, you may
specify one of two alternative field lengths, 128 or 192. You do
this by placing these numbers after the word FIXED (with a space
When you have finished saving data to the tape, remember to
close the file with eg CLOSE #1
This will generate the message "PRESS CASSETTE STOP & PRESS
ENTER", so as before ensure that there is no screen display to be
When the computer is saving data, it does so one field at a
time, amd it is essential the computer has control of the cassette
motor. If your remote control does not function, fit the polarity
reverser (provided with the TI Tape Cable) between the remote
socket on your tape recorder (the small one: 2.5mm) and the small
jack plug on the lead from the computer. If you have purchased a
third party lead and require the polarity reversing, you should
ask your supplier to do so. It is possible to swop the wires
yourself, but with some systems there may be problems as the
screening may be broken.
To load your saved data, you must reopen the file, this time
specified as an INPUT file. If you used long field lengths when
saving the data, you MUST specify the same length in the OPEN
statement to load the data. Similarly if a file is saved in
INTERNAL format, you MUST read it in the same format.
If you have placed several values in one field, you must read
them in the same way- if you have used:
then you MUST read four NUMERIC variables,although the names
If a numeric variable has been saved, you must read a numeric
variable. A field containing string data must be input to a string
Your tape files contain the values of the variables printed to
them (or direct numbers or strings). The variable name is not
saved, and the variable is not affected by saving its value.
Have a look at the file management program in Vince Apps book
of Programs for the 99/4A for an example of using tape files.
Remember to CLOSE the file when you have finished with it.
Tape files can occupy large amounts of tape, and if you are
saving a large number of items, you will need at least a C15 or
Retreiving the data that has been saved -
You may find that you need to slightly alter the volume level
on your tape recorder to load data files correctly. It IS possible
to load corrupted data if the volume is slightly incorrect, and
this may result in your program 'crashing' with an error message
such as 'BAD VALUE' which is not immediately caused by an
incorrect volume setting.
NOTE: EOF is not available for tape files.
Typical routines to SAVE and LOAD high scores for a game:
TO SAVE a high score, which is in a variable called HISCORE
100 REM DO NOT OVERRECORD YO
110 REM ONLY RECORD DATA ON
120 OPEN #1:"CS1",INTERNAL,O
130 PRINT #1:HISCORE
140 CLOSE #1
200 REM TAPE MUST BE IN SAME
210 REM AS AT START OF ABOVE
220 OPEN #1:"CS1",INTERNAL,I
230 INPUT #1:HISCORE
240 CLOSE #1
If you graduate on to DISK BASED filing, the 99/4A offers many
more options, to give you greater control and access. This
includes variable length files for better use of disk space,
update mode which allows you to read and write to a single open
file, and relative files which allow you to read or write to a
specific record within the file. The disk system also allows the
use of named files, and of course greater speed.
If you insert the Mini Memory module, this has an internal battery (which may need replacing) and
you are able to store data onto the module to move it easily from one console to another. If you are using a TI99/4a emulator, choose the Mini Memory module, THEN SELECT
TI BASIC and the following will apply also:
You may use the MINI MEMORY MODULE as a file storage device.It
is treated in a similar way to disk files except that only one
file can be saved to the module, called "MINIMEM". For minimem or
disk, if you use FIXED with no number, the file is padded to 80
For Minimem operation,your opening line may be as short as:
The file is assumed by the computer to be
FIXED 80,SEQUENTIAL,DISPLAY (care!),UPDATE.
Any of these assumptions (or defaults) can be altered by adding
the definition you want to the OPEN statement. Minimem will retain
its data files provided you switch the console off before
inserting and removing the module and do not use it for anything
else. Minimem also permits the memory expansion to be used for
data storage (see Mini Memory Manual) but this data is lost when
you disconnect the power.
It is possible for 99/4a
owners to save and read their own data in this format if the
Personal Record Keeping or Statistics modules were in the module
These two modules add several new subprograms when TI BASIC is
selected, but as this is not advertised may be amended in future.
Their use is fairly technical, as memory has to be reserved by the
programmer and is not covered here.
THE INFORMATION IN THIS BOOK IS FREE. It may be copied, distributed and/or modified under the conditions set down in the Design Science License published by Michael Stutz at http://dsl.org/copyleft/dsl.txt
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