gary@brb.isnet.inmos.co.uk (10/06/90)
In article <1990Oct2.131933.18588@cbnewsl.att.com>, hojo@cbnewsl.att.com (HC Johnson) writes: > > I have never heard of an Adaptec problem. I have 2 Adaptec 4000A and the > Atari clone (in a SH204). All of them properly accept the bad bit map > (could be called bad sector list) and map them out perfectly. I know they > are doing it right because I have drives that completely died using the old > HDX and that is why I wrote my own formatter. > > Howard Johnson I am intrigued by this. Does the Adaptec 4000A have some non-volatile memory in which the bad sector list is stored? -or- Does the Adaptec have some RAM in which the list is stored, which is stored on the disk and automatically read by the Adaptec on power-on? -or- Does the Adaptec have some RAM ... , which has to be initialised by the driver software (booted from sector 0?), which knows where the bad sector list is stored on the disk? --Gary ============================================================================ Gary Morton Inmos Ltd, Aztec West, Bristol | EMail(UK) ----------| +44 454 616616 X523 |------------| gary@brb.isnet.inmos.co.uk The opinions above are my personal views | EMail(ROW) and may not reflect Inmos policy. | gary@brb.isnet.inmos.com ============================================================================
hojo@cbnewsl.att.com (HC Johnson) (10/09/90)
In article <186.270cc984@brb.isnet.inmos.co.uk>, gary@brb.isnet.inmos.co.uk writes: > > Does the Adaptec 4000A have some non-volatile memory in which the bad > sector list is stored? > -or- > Does the Adaptec have some RAM in which the list is stored, which is stored > on the disk and automatically read by the Adaptec on power-on? > -or- > Does the Adaptec have some RAM ... , which has to be initialised by the > driver software (booted from sector 0?), which knows where the bad sector > list is stored on the disk? > Bad sectors and the Adaptec. Bad sectors are mapped in zones on the hard disk. This is why the lights blink so funny when you turn on an Adaptec based controler. The whole effect of a bad sector list is to shrink the total size of the disk. It just seems to shrink a bit more for its internal tables. The Adpatec has effectively two format commands; short and long. Short has new bad sectors, long allows passing them as part of the command. Howard Johnson ATT BELL LABS att!lzsc!hcj hcj@lzsc.att.com