Format of DOS 5.0-6.0 disk buffer info:
Offset Size Description )
00h DWORD pointer to least-recently-used buffer header (may be in HMA)
(see #01655)
04h WORD number of dirty disk buffers
06h DWORD pointer to lookahead buffer, zero if not present
0Ah WORD number of lookahead sectors, else zero (the y in BUFFERS=x,y)
0Ch BYTE buffer location
00h base memory, no workspace buffer
01h HMA, workspace buffer in base memory
0Dh DWORD pointer to one-segment workspace buffer in base memory
11h 3 BYTEs unused
14h WORD ???
16h BYTE flag: INT 24 fail while making an I/O status call
17h BYTE temp storage for user memory allocation strategy during EXEC
18h BYTE counter: number of INT 21 calls for which A20 is off
19h BYTE bit flags
bit 0: ???
bit 1: SWITCHES=/W specified in CONFIG.SYS (don't load
WINA20.SYS when MS Windows 3.0 starts)
bit 2: in EXEC state (INT 21/AX=4B05h)
1Ah WORD offset of unpack code start (used only during INT 21/AX=4B05h)
1Ch BYTE bit 0 set iff UMB MCB chain linked to normal MCB chain
1Dh WORD minimum paragraphs of memory required by program being EXECed
1Fh WORD segment of first MCB in upper memory blocks or FFFFh if DOS
memory chain in base 640K only (first UMB MCB usually at
9FFFh, locking out video memory with a DOS-owned memory
block)
the MCB this word points at contains a valid link into high
memory even if it is marked with a 'Z' indicating the last
memory block
21h WORD paragraph from which to start scanning during memory allocation
SeeAlso: #01652,#01653