Download CPM 14 Manual - Altair 8800 Clone

4
Read Console Character
Write Console Character
Read Reader Character
Write Punch Character
Write List Device Character
Set I/0 Status
Interrogate Device Status
Print Console Buffer
Read Console Buffer
Interrogate Console Status
The exact details of BIOS access are given in Section 2.
The BDOS primitives include the following operations:
Disk System Reset
Drive Select
File Creation
File Open
File Close
Directory Search
File Delete
File Rename
Read Record
Write Record
Interrogate Available Disks
Interrogate Selected Disk
Set DMA Address
The details of BDOS access are given in Section 3.
2.
BASIC I/0 FACILITIES
Access to common peripherals is accomplished by passing a
function number and information address to the BIOS. In general,
the function number is passed in Register C, while the information address is passed in Register pair D,E. Note that this
conforms to the PL/M conventions for parameter passing, and thus
the following PL/M procedure is sufficient to link to the BIOS
when a value is returned:
DECLARE ENTRY LITERALLY
MON2:
'0005H'; /* MONITOR ENTRY */
PROCEDURE (FUNC, INFO) BYTE;
DECLARE FUNC BYTE, INFO ADDRESS;
GO TO ENTRY;
END MON2;