Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
200 words
Apparatus (7) for assembly and disassembly of packets (43) of data communicated between a host computing environment (1) and a sequentially accessed mass storage device (25) the apparatus comprising: first interface means (8) for coupling to the host computing environment, for receiving host-transmitted records to be written to the mass storage device, and for sending to the host computing environment data and status information read from the mass storage device; tape packet assembly/disassembly means (TPAD) (11 through 22) coupled to the first interface means for assembling into a buffer (13) packets separated by gaps, each packet comprising data portions (14,16,18) (29) and trailer portions (15,17,19) (36) of information corresponding to host-transmitted records, the data portions containing data (31,32) from the host-transmitted records and the trailer portions containing descriptive information (33,37) about the structure of the data portions, including the location of any tape mark that occurred in the host-transmitted record, and for disassembling back into host-transmitted records and associated status indications packets comprising data portions and trailer portions; and second interface means (23) coupled to the TPAD for coupling to the mass storage device (25) for writing packets in the buffer thereto, and for reading packets therefrom into the buffer.
Claim 2
Dependent Claim
200 words
Apparatus (7) for assembly and disassembly of packets (43) of data communicated between a host computing environment (1) and a sequentially accessed mass storage device (25) the apparatus comprising: first interface means (8) for coupling to the host computing environment, for receiving host-transmitted records to be written to the mass storage device, and for sending to the host computing environment data and status information read from the mass storage device; tape packet assembly/disassembly means (TPAD) (11 through 22) coupled to the first interface means for assembling into a buffer (13) packets separated by gaps, each packet comprising data portions (14,16,18) (29) and trailer portions (15,17,19) (36) of information corresponding to host-transmitted records, the data portions containing data (31,32) from the host-transmitted records and the trailer portions containing descriptive information (33,37) about the structure of the data portions, including the location of any tape mark that occurred in the host-transmitted record, and for disassembling back into host-transmitted records and associated status indications packets comprising data portions and trailer portions; and second interface means (23) coupled to the TPAD for coupling to the mass storage device (25) for writing packets in the buffer thereto, and for reading packets therefrom into the buffer.
Claim 3
Dependent Claim
30 words
Apparatus as claimed in claim 1 wherein the TPAD can divide data portions received via the first interface means (8) between packets and records this division in said trailer portions.
Claim 4
Dependent Claim
36 words
Apparatus as claimed in claim 1 or 2 wherein in normal operation writing of data from the buffer (13) via the second interface means (23) to the mass storage device (25) occurs only in complete packets.
Claim 5
Dependent Claim
64 words
Apparatus as claimed in claim 1,2 or 3 wherein a read command is carried out by reading a complete packet of data containing the relevant record to the buffer (13), together with the next succeeding packets until the buffer (13) is full, and using the information in the trailer portions to disassemble the packets before sending relevant record back to the host computing environment.