Data transmission system using independent adaptation processes associated with storage unit types for directly converting operating system requests to SCSI commands

Claim 1

A data transmission system (MSP 1 , MSP 2 ) between a computer parallel bus (PSB) and a mass memory (SCSI 1 , SCSI 2 ) on a SCSI bus having a large number of data storage units (D 1 to D 5 , T 6 , D 7 to D 11 , T 12 ) connected to one another by a specific connection (BD 1 , BD 2 ) to which the system is physically connected, that includes a central microprocessor (CPU) connected to at least one memory (SRAM) containing an operating system (GPOS) designed to be executed by it comprising: means of transferring frames (MPC, B 2 , B 3 , VRAM, B 1 , DMAC, CTR 1 , CTR 2 ) between the computer bus and the connection, whose work is organized and managed by the microprocessor, including a data storage memory (VRAM) located between the computer bus and the connection; the operating system (GPOS) being associated with at least one specific application (A 1 , A 2 ) to transmit data between the computer bus (PSB) and said connection (BD 1 , BD 2 ); said data transmission system including at least one input/output microprocessor (CTR 1 , CTR 2 ) responsive to the central micro processor (CPU), connected to said data storage memory (VRAM) and to said connection; said at least one application including: a process for initialization (P 0 ) of an entire application, a plurality of separate adaptation processes independent from one another (P 1 to P 6 , P 7 to P 12 ), each of said adaptation processes associated with a certain type of storage unit, said processes directly converting commands sent via message semaphore from said GPOS into commands that comply with SCSI protocol, each said adaptation process communicating with one another by message semaphore to assist conversion, the conversion being carried out in the VRAM through correspondence tables located therein; and at least one management process authorizing the input/output microprocessor to transfer physically the commands and data in frames corresponding to them between the memory and the connection as soon as the corresponding adaptation process has finished said adaptation wherein the storage memory (VRAM) has second memory zones (BP 1 to BP 12 ), each assigned to storage of data intended for each of the different storage units, and tables (TP 1 to T 12 ) each associated with a certain one of them, including the address of the second memory zone associated with the same unit and the length of the necessary data stored there.