INT E0 - REAL/32 - "S_SYSDAT" - GET SYSTEM DATA AREA CL = 9Ah Return: ES:AX -> system data area (see #04048) may destroy SI,DI Format of REAL/32 system data area: Offset Size Description (Table 04048) 00h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of supervisor entry point 04h 36 BYTEs reserved 28h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of XIOS entry point 2Ch DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of XIOS initialization point 30h 8 BYTEs reserved 38h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of IRET dispatcher entry point 3Ch DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of RETF dispatcher entry point 40h WORD segment of operating system code 42h WORD paragraph address of first Resident System Process (RSP) 44h WORD paragraph after OS system area 46h BYTE reserved 47h BYTE number of system console devices 48h BYTE number of system list (printer) devices 49h BYTE number of Character Control blocks 4Ah BYTE number of system flags 4Bh BYTE current search disk 4Ch WORD maximum memory per process 4Eh BYTE reserved 4Fh BYTE "dayfile" (flag, true if FFh) 50h BYTE default disk for temporary files 51h BYTE system ticks per second (typically 60) 52h WORD offset of Locked Unused list 54h WORD offset of CCB table 56h WORD offset of system flag table 58h WORD offset of root of Memory Descriptor Unused list 5Ah WORD offset of Memory Free list 5Ch WORD offset of Process Unused list 5Eh WORD offset of Queue Unused list 60h 4 WORDs (no longer used) QMAU 68h WORD offset of root of Ready List 6Ah WORD offset of root of Delay List 6Ch WORD offset of Dispatcher Ready list 6Eh WORD offset of root of Poll List 70h WORD reserved 72h WORD offset of root of Thread List 74h WORD offset of root of Queue List 76h WORD offset of Memory Allocation list 78h WORD segment of version string 7Ah WORD BDOS version number 7Ch WORD OS version number 7Eh WORD number of days since 1978/01/01 80h BYTE current time: hour 81h BYTE current time: minute 82h BYTE current time: second 83h BYTE number of XIOS consoles 84h BYTE number of XIOS list (printer) devices 85h BYTE total number of character devices 86h WORD offset of LCB table 88h WORD bitmap of open files 8Ah BYTE maximum locked records per process 8Bh BYTE maximum open files per process 8Ch WORD offset of process descriptor for math coprocessor's owner 8Eh WORD offset of Auxiliary Control Block 90h 8 BYTEs reserved 98h WORD offset of root Memory Window Descriptor 9Ah WORD reserved 9Ch BYTE number of Auxiliary Control Blocks 9Dh BYTE default search disk 9Eh BYTE reserved 9Fh BYTE number of physical consoles A0h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of 8087 interrupt handler A4h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of default 8087 exception handler ... reserved C00h 82 BYTEs XIOS header structure (see #04049) Format of REAL/32 XIOS header structure: Offset Size Description (Table 04049) 00h 3 BYTEs XIOS initialization entry point 03h 3 BYTEs XIOS service entry point 06h WORD segment address of system data 08h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of supervisor entry point 0Ch BYTE set tick flag 0Dh BYTE ticks per second 0Eh BYTE global Door Open interrupt flag 0Fh BYTE number of Auxiliary Control Blocks 10h BYTE number of physical consoles 11h BYTE number of virtual consoles 12h BYTE number of logical consoles 13h BYTE number of list control blocks 14h WORD offset of CCB table 16h WORD offset of LCB table 18h 16 WORDs offsets into DPH for drives A-P 38h WORD buffer size in paragraphs 3Ah WORD offset of ACB table 3Ch WORD used by OEM(Original Equipment Manufacturer) a company which purchases components that are resold as part of its own products under the company's own brand name, e.g. a Gateway 2000-branded monitor may actually be a Mag or NEC monitor. 3Eh WORD offset of CCB pointer array 40h WORD offset of LCB pointer array 42h WORD offset of ACB pointer array 44h BYTE 'first' flag 45h BYTE unused 46h WORD offset of print device support table 48h WORD offset of aux device support table 4Ah WORD XIOS extra segment 4Ch WORD segment of save end address for debug 4Eh WORD segment of save start address for debug 50h BYTE number of main virtual console 51h WORD segment of XIOS code SeeAlso: #04048