User`s guide

Read a character from CONIN:
Read a character buffer from CONIN:
Write a character to CONOUT:
Write a string of characters to CONOUT:
Write a block of characters to CONOUT:
Read a character from AUXIN:
Write a character to AUXOUT:
Write a character to LST:
Write a block of characters to LST:
Interrogate CONIN:, AUXIN:, AUXOUT: ready
CP/M 3 cannot run unless CONIN: and CONOUT: are assigned to a physical
console. The remaining logical devices can remain unassigned. If a logical output
device is not assigned to a physical device, an output BDOS call to the logical device
performs no action. If a logical input device is not assigned to a physical device, an
input BDOS call to the logical device typically returns a CTRL-Z (lAH), which
indicates end-of-file. Note that these actions depend on your system's BIOS
implementation.
2.2.1 BDOS Console I/O
Because a transient program's main interaction with its user is through the console,
the BDOS supports many console I/O functions. Console PO functions can be divided
into four categories: basic console I/O, direct console I/O, buffered console input,
and special console functions. Using the basic console I/O functions, programs can
access the console device for simple input and output. The basic console I/O func-
tions are:
1. Console Input - Inputs a single character
2. Console Output - Outputs a single character
9. Print String - Outputs a string of characters
11. Console Status - Signals if a character is ready for input
111. Print Block - Outputs a block of characters
The input function echoes the character to the console so that the user can identify
the typed character. The output functions expand tabs in columns of eight characters,
2-3
2.2 BDOS Serial Device I/O CP/M 3 Programmer's Guide