30 Jan
2012
30 Jan
'12
6:39 p.m.
Pete Turnbull wrote:
Jules Richardson wrote:
I thought when writing that I might have that backwards! :-)
Re. Tony's mention of the 380Z, yes I think it did treat surfaces of the
media as different drives too, just with the surface designations iterating
"drive first" rather than Acorn's "surface first".
I expect that most machines of the era came with either single or
double-sided drives and the OS/firmware was coded to treat the entire disk
as a single entity.
cheers
Jules
... unlike Acorn, where the DFS firmware would
treat separate disk
surfaces as completely different logical drives:
logical drive 0 = physical drive 1, top surface
logical drive 1 = physical drive 2, top surface
logical drive 2 = physical drive 1, bottom surface
logical drive 3 = physical drive 2, bottom surface
Access to logical drives 1 and 3 would give an error in a single-drive
system.
Not quite right, because upside down.