Insert a BASIC-DOS diskette in drive A: of an IBM PC and turn the machine on. If the machine has a hard disk, BASIC-DOS first displays:
BASIC-DOS 2.00
Press a key to start...
Press any key to start BASIC-DOS, or press Esc to boot from the hard disk instead. The following messages should then appear on your screen:
BASIC-DOS 2.00 for the IBM PC
Copyright (c) PCJS.ORG 1981-2026
BASIC-DOS Command Processor
Floating-point software installed
A>
The “Floating-point” line tells you how BASIC-DOS will perform floating-point calculations:
The A> is the BASIC-DOS prompt. The prompt displays which diskette drive is the default and indicates that BASIC-DOS is ready to accept commands from the keyboard.
Unlike PC DOS, BASIC-DOS doesn’t automatically run an AUTOEXEC.BAT file. Instead, each session’s startup command (if any) is specified on a SHELL= line in CONFIG.SYS.
The BASIC-DOS prompt accepts commands up to 254 characters long. Any characters typed beyond that limit are ignored. Press the Enter key to submit all characters currently displayed as the next command.
Other special keys include:
Other special key sequences that can be typed at any time include:
You can also use the KEYS command to display a brief summary of special keys.
A command line can contain more than one command, separated by colons (eg, CLS:DIR). BASIC-DOS commands and BASIC statements can be freely mixed, so the following is a valid command line:
FOR I = 1 TO 3:PRINT I;:NEXT
Note that assignments typed at the prompt must begin with LET (eg, LET A = 1), since BASIC-DOS would otherwise look for a program named A.
To run a program, type its name, optionally followed by any arguments the program accepts. If you don’t specify an extension, BASIC-DOS looks for a file with the extension COM, EXE, BAT, or BAS, in that order.
For example, if a disk contains both DONKEY.COM and DONKEY.BAS, typing DONKEY runs DONKEY.COM, and typing DONKEY.BAS runs DONKEY.BAS.
When a BAS program that you ran from the prompt ends, it remains loaded, along with its variables, so you can LIST it, examine its variables (eg, PRINT A), or RUN it again. RUN reuses the program’s compiled code, so the program starts immediately, unless the program or its variables have changed since it was compiled.
If a name matches a BASIC keyword that can’t be used by itself (eg, CIRCLE), BASIC-DOS runs the program with that name instead (eg, CIRCLE.BAS).
To stop a program, press Ctrl-C (or Ctrl-Break). If the program doesn’t respond, press Ctrl-Alt-Del.
The output of a command can be sent to a file instead of the screen:
DIR > FILES.TXT creates (or truncates) FILES.TXT and writes the output to itDIR >> FILES.TXT appends the output to FILES.TXTThe output of one command can also be sent to the input of another command, using a pipe (|):
DIR | CASE
Each command after the first runs in its own background session, so all commands in a pipeline run at the same time. The output of a pipeline can also be redirected (eg, DIR | CASE > TEST).
Input redirection (<) isn’t supported yet.
BASIC-DOS can run several programs at once, each in its own session. A session has its own console, which can occupy the entire screen or just part of it (eg, the left and right halves of the screen, as in the BASIC-DOS Demos); the console with a double-line border is the one that has focus, which means that it receives keyboard input.
Press Shift-Tab to switch the focus to the next session.
The number of sessions and the size and position of their consoles are defined in CONFIG.SYS (see CONSOLE= and SESSIONS=).
The HELP command lists all commands, and HELP followed by the name of a command or function (eg, HELP MID$) displays a brief description of it.
Copyright (c) 2020-2026 Jeff Parsons Released under MIT License