Title:

CSIRO Projects


Description:

BelSoft undertook various projects in the new Division of Information Technology (DITMELA). All coding was done in C under Unix. The machines used were a SUN 3/50 workstation and a MicroVAX. A contribution was made on these projects.

Reimplemented the bad block forwarding mechanism of UNIX for the SUN. Bad block forwarding is used to avoid the use of bad blocks on the disk. When access to such a block is made UNIX automatically looks up a table and uses an alternative block.

The kernel installed at the time didn't have certain system calls so the normal method of obtaining disk information (in particular a XYLOGIC disk) could not be used. Instead ioctl calls had to be combined to obtain this information. In addition code was written that copies the bad block to the alternative bad block and marks the new bad headers.

Implemented a language to directly describe the tables in OSI standards. This would avoid writing code to implement these tables. Since most of the code is repeated amongst different requests we also had in mind to make the whole system table driven to save space.

The major example we worked in was the FTAM protocol. Yacc was used to parse the language. Code was written to generate the table and its driver from the parse tree. Various small subsections of the FTAM table were coded up and revealed up to one third saving in the size of the code. A table driven version of FTAM has been marketed by CSIRO.