INT 2F - JAM.SYS v1.10+ - "GetVersion" - INSTALLATION CHECK AX = 5200h Return: AH = 80h (successful) if installed BX = internal JAM.SYS version number CX = size of JAMINFO structure (see #02831,#02832) 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). SeeAlso: AX=5201h Format of JAMINFO v1.10 structure: Offset Size Description (Table 02831) 00h 25 BYTEs extended BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. parameter block (BPBsee BIOS Parameter Block) 19h 11 BYTEs ??? 25h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. total number of sectors in JAM archive file (size of compressed data area) 29h BYTE flags (see #02833) 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 #02834) 10Bh DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of the host-drive DPBsee Drive Paramter Block (Drive Parameter BlockThe DOS Drive Parameter Block stores the description of the media layout for a logical drive, as well as some housekeeping information. See also INT 21h Function 1Fh and INT 21h Function 32h.) 10Fh DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. number of free sectors in JAM archive file 113h WORD device status word (see #02835) SeeAlso: #02832 Format of JAMINFO v1.20 structure: Offset Size Description (Table 02832) 00h 25 BYTEs extended BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. parameter block (BPBsee BIOS Parameter Block) 19h BYTE physical driver number 1Ah BYTE reserved 1Bh BYTE extended boot record signature 1Ch DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. volume serial number 20h 11 BYTEs volume label 2Bh 8 BYTEs file system ID 33h DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. total number of sectors in JAM archive file (size of compressed data area) 37h BYTE flags (see #02833) 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 #02834) 11Ah DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. address of the host-drive DPBsee Drive Paramter Block (Drive Parameter BlockThe DOS Drive Parameter Block stores the description of the media layout for a logical drive, as well as some housekeeping information. See also INT 21h Function 1Fh and INT 21h Function 32h.) 11Eh DWORDDoubleword; four bytes. Commonly used to hold a 32-bit segment:offset or selector:offset address. number of free sectors in JAM archive file 122h WORD device status word (see #02835) Note: the first 33h bytes are copied from the archive file's boot sector SeeAlso: #02831 Bitfields for JAMINFO flags: Bit(s) Description (Table 02833) 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 SeeAlso: #02831,#02832 Format of JAM FRAGMENT structure: Offset Size Description (Table 02834) 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) SeeAlso: #02831,#02832 (Table 02835) 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 SeeAlso: #02598 at INT 2F/AX=0802h