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Command Description
LIST “H1:PROGRAM.BAS” Save a BASIC program
NEW Clear the computer's memory by erasing any old instructions
DOS Switch to DOS
PRINT FRE(0) Check how much memory is available
BYE Activate Self Test


Examples of using PRINT:

PRINT "TEXT",                   TEXT followed by a tab
PRINT "TEXT";"ABC"              Concatenated strings: TEXTABC
PRINT "TEXT":PRINT "ABC"        Two instructions in the same line
PRINT                           New line


The Atari disk input/output commands:

  • OPEN #num, code, 0, file
  • CLOSE #num
  • PRINT #num
  • INPUT #num
Parameter Description
num A reference number between 1 and 7 that is used to refer to the file throughout a program.
The reference number is also called IOCB number (Input/Output Control Block).
code An open code is a number that tells the computer if you want to read, write:
4 - read
8 - write; first erase the file and start writing at the beginning
12 - read/write
9 append; add to end of file
file A file specification composed of the device and filename.


DIM F$(20)
OPEN #1,8,0,F$                          Open a file TEST.DAT for writing
PRINT #1;"HELLO!"                       Write a string to the file
PRINT #1; 123.4                         Write a number (as a string) to the file
PRINT #1;"THERE IS MORE:"; 987          Write a string and a number (as a string) to the file
CLOSE #1                                Flush the buffer and close the file
OPEN #2,4,0,F$                          Open a file TEST.DAT for writing
REM                                     Note that we could use #1 again as the file has been closed
DIM D$(30):REM                          Allocate memory for a string we want to read from the file
INPUT #2,D$                             Read the string to the variable D$
PRINT D$:REM                            Prints HELLO!
INPUT #2,D$:REM                         Read the next string (which is a number stored as a string)
PRINT D$:REM                            Prints 123.4

More on using disks with Atari BASIC can be found here.


  • ^ - Control key
  • ! - Shift key
  • Delete a line by typing its number.
  • Stop the LIST instruction: Control + 1
  • Display a graphical symbol: Control + key
  • Switch to graphical symbols mode: Control + Caps
  • Insert a space: Control + Insert
  • Insert a line above the current line: Shift + Insert
  • Delete the current line: Shift + Delete
  • Arrows: Control + arrow key
notes/atari/basic.txt · Last modified: 2016/10/05 by admin