IBM 5150 PC Technical Reference (6025005, August, 1981) (PDF)

Table 31. BASIC and DOS Reserved Interrupts
(80-3FF)
ADDRESS
HEX
INTERRUPT
HEX
80-83 20
84-87 21
88-8B 22
8C-SF 23
90-93 24
94-97 25
98-9B 26
9C-9F 27
AO-FF 28-3F
100-1 FF 40-7F
200-217 80-85
218-3C3 86-FO
3C4-3FF F1-FF
FUNCTION
DOS Program Terminate
ODS Function Call
ODS Terminate Address
ODS CTRL-BRK Exit Address
ODS Fatal Error Vector
DOS Absolute Disk read
ODS Absolute Disk write
ODS Terminate, Fix in Storage
Reserved for 0 OS
Not Used
Reserved By BASIC
Used by BASIC Interpreter while BASIC is Running.
Not Used
Table 32. Reserved Memory Locations (400-SFF)
ADDRESS
HEX
MODE
400-48F ROM BIOS
490-4CF ODS
400-4EF
4FO-4FF
500-5FF
500 ODS
504 ODS
510-511 BASIC
512-515 BASIC
516-519 BASIC
51A-51O BASIC
FUNCTION
See BIOS Listing
Used by ODS Mode Command
Reserved
Reserved as Intra·Application Communication
area for any application.
Reserved for ODS and BASIC
Print Screen status flag store.
O-Print screen not active or successful print
screen operation.
1-Print screen in progress.
255-Error encountered during print screen
operation.
Single drive mode status byte.
BASIC's segment address store.
Clock interrupt vector segment: offset store.
Break key interrupt vector segment: 'offset store.
Disk error interrupt vector segment: ·offset store.
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