INT 78 - UofSalford DBOS DOS extender - API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running. Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.
AH = function
00h (PB) display 32-bit memory specified by command argument
01h (PT) display 32-bit instruction(s) specified by command arg
02h specify offset to subsequent PB and PT commands
03h switch to protected mode
DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. following INT instruction point to map; protected-mode
entry point is immediately following the DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address.
Return: never
Note: if bit 31 of the map address is set, only a stub was
loaded by DOS and DBOS will load the entire program
04h specify that subsequent load (AH=03h) should leave program in
memory
05h release program from memory
06h set break point at address and option count from commandline
07h resume program execution
08h single-step program
09h set read/write breakpoint using 386 debug registers
0Ah set write breakpoint using 386 debug register
0Bh set memory byte to new value
0Ch display CPU(Central Processing Unit) The microprocessor which executes programs on your computer. registers
0Dh run until specified program address reached
0Fh print trace from program map
10h specify an offset using a map symbol
14h print memory without any offset
18h switch DBOS into/out of test mode (ON/OFF commandline args)
1Dh get address of real/protected-mode communication buffer
Return: ES:BP -> comm buffer
1Eh set real-mode memory size (specify how much real-mode memory
to leave free when running FTN77 programs)
22h uninstall DBOS
24h force DBOS to emulate coprocessor instructions
26h set named DBOS switches from commandline
27h reset named DBOS switched from commandline
2Ah set list of dynamic link libraries to contents of commandline
file
35h specify that subsequent load (AH=03h) should stop at first
instruction
Return: ???
Notes: DBOS supports functions 00h through 50h; many of these functions
provide a low-level debugging interface
command arguments are read from the calling program's PSPsee Program Segment Prefix
SeeAlso: INT 79"DBOS"
Index: uninstall;DBOS DOS extender