Int 2F Fn 5200  - Jam.sys V1.10+ - "getversion" - Installation Check       [k]

   AX = 5200h

Return: AH = 80h (successful) if installed
   BX = internal JAM.SYS version number
   CX = size of JAMINFO structure (see #2517,#2518)
   DX = JAM.SYS segment address
Program: JAM.SYS is a main component of the JAM Real-Time Data Compression
     Utilities by George A. Reznik and friends (JAM Software).

See Also: AX=5201h

Format of JAMINFO v1.10 structure:
Offset Size    Description (Table 2517)
 00h 25 BYTEs  extended BIOS parameter block (BPB)
 19h 11 BYTEs  ???
 25h   DWORD   total number of sectors in JAM archive file
       (size of compressed data area)
 29h   BYTE    flags (see #2519)
 2Ah 127 BYTEs full JAM archive file name
 A9h   WORD    the number of fragments in archive file
 ABh 96 BYTEs  archive file fragmentation list -
       array of 16 FRAGMENT structures (see #2520)
10Bh   DWORD   address of the host-drive DPB (Drive Parameter Block)
10Fh   DWORD   number of free sectors in JAM archive file
113h   WORD    device status word (see #2521)

See Also: #2518

Format of JAMINFO v1.20 structure:
Offset Size    Description (Table 2518)
 00h 25 BYTEs  extended BIOS parameter block (BPB)
 19h   BYTE    physical driver number
 1Ah   BYTE    reserved
 1Bh   BYTE    extended boot record signature
 1Ch   DWORD   volume serial number
 20h 11 BYTEs  volume label
 2Bh  8 BYTEs  file system ID
 33h   DWORD   total number of sectors in JAM archive file
       (size of compressed data area)
 37h   BYTE    flags (see #2519)
 38h 128 BYTEs full JAM archive file name
 B8h   WORD    the number of fragments in archive file
 BAh 96 BYTEs  archive file fragmentation list -
       array of 16 FRAGMENT structures (see #2520)
11Ah   DWORD   address of the host-drive DPB (Drive Parameter Block)
11Eh   DWORD   number of free sectors in JAM archive file
122h   WORD    device status word (see #2521)

Note:  the first 33h bytes are copied from the archive file's boot sector

See Also: #2517

Bitfields for JAMINFO flags:
Bit(s) Description (Table 2519)
 2-0   reserved
 3 (v1.20+)
 4 enable direct write requests (Int 26h, non-DOS requests, etc.)
 5 read-only mode
 6 no write-behind caching
 7 full undelete-compatible allocation strategy

See Also: #2517,#2518

Format of JAM FRAGMENT structure:
Offset Size    Description (Table 2520)
 00h   WORD    starting sector (low word)
 02h   BYTE    starting sector (high byte)
 03h   WORD    size of fragment (low word)
 05h   BYTE    size of fragment (high byte)

See Also: #2517,#2518

(Table 2521)
Values for JAM.SYS status (high byte):
 00h   successful
 01h   drive is not a JAM drive
 02h   drive is already attached
 03h   archive file cluster size value is larger than driver's one
 04h   drive is not attached
 05h   drive is locked
 06h   drive is not locked
 07h   bad physical-level request
 08h   host drive reading/writing error
 09h   bad entries in JAM descriptor table
 0Ah   compressed data integrity error
 0Bh   archive file overflow
 0Ch   bad DOS request
 0Dh   incorrect parameters in JAMINFO structure

Note:  the low byte of the status is the DOS error code for the Host drive

See Also: #2285 at INT 2F/AX=0802h