More On TI Memory

Many owners of the TI-99/4A would be interested in determining the exact amount of available memory (in bytes). This two-line program is very simple and can save a lot of hair pulling when you write programs which fill the memory. Here is the program:

STEP 1

Enter the following:

1 A = A+8
2 GOSUB 1

Do not use a variable that has already appeared in the program. For example, if you have used the variable "A" within the program, choose another. Second, the program must work correctly before using this mini-program.

STEP 2

Once this is entered into the memory, enter the RUN command. The process will take between 15 and 30 seconds to execute, depending upon the length of your program. After execution, MEMORY FULL IN 1 will appear. Now enter PRINT A (no line number) and a value will appear on the screen. This value is the number of bytes remaining in the computer's memory.

To determine the total amount of free memory available, clear the memory (store your program first) and repeat Steps 1 and 2. The value displayed will be 14536. There are 14536 free bytes available (the mini-program itself uses 40 bytes, so add 40 to the 14536). The computer is advertised as having 16K bytes. 1424 are used for screen display, etc. So, when a program is stored in the memory and you want to determine how many bytes the program used, enter the following:

PRINT 14576-A

Howard Patlik