System information

4A09H+b JMP CONIN ;READ CONSOLE CHARACTER IN
4A0CH+b JMP CONOUT ;WRITE CONSOLE CHARACTER OUT
4A0FH+b JMP LIST ;WRITE LISTING CHARACTER OUT
4A12H+b JMP PUNCH ;WRITE CHARACTER TO PUNCH DEVICE
4A15H+b JMP READER ;READ READER DEVICE
4A18H+b JMP HOME ;MOVE TO TRACK 00 ON SELECTED DISK
4A1BH+b JMP SELDSK ;SELECT DISK DRIVE
4A1EH+b JMP SETTRK ;SET TRACK NUMBER
4A21H+b JMP SETSEC ;SET SECTOR NUMBER
4A24H+b JMP SETDMA ;SET DMA ADDRESS
4A27H+b JMP READ ;READ SELECTED SECTOR
4A2AH+b JMP WRITE ;WRITE SELECTED SECTOR
4A2DH+b JMP LISTST ;RETURN LIST STATUS
4A30H+b JMP SECTRAN ;SECTOR TRANSLATE SUBROUTINE
Listing 6-2. BIOS Entry Points
Each jump address corresponds to a particular subroutine that performs the specific function, as
outlined below. There are three major divisions in the jump table: the system reinitialization,
which results from calls on BOOT and WBOOT; simple character I/O, performed by calls on
CONST, CONIN, CONOUT, LIST, PUNCH, READER, and LISTST; and disk I/O, performed
by calls on HOME, SELDSK, SETTRK, SETSEC, SETDMA, READ, WRITE, and SECTRAN.
6.6 BIOS Entry Points CP/M Operating System Manual
6-16