13 Dec
2022
13 Dec
'22
4:30 p.m.
On Dec 13, 2022, at 8:14 AM, Ralph Corderoy <ralph(a)inputplus.co.uk> wrote:
Hi Bakul,
IIRC the slow part was due to running some common apps! Not much buffering
allowed on a 256KB machine so by the time the app asks for the next block,
on a 1:1 interleave the block would be past the read head and you had to
spend an extra revolution to grab it!
Fortune 32:16 was a 5.6Mhz machine and
couldn't process 1020KB/sec
(17 sectors/track of early ST412/ST506 disks) fast enough. As Warner
said, one dealt with it by formatting the disk so that the logical
blocks N & N+1 (from the OS PoV) were physically more than 1 sector
apart.
Sticking with ST506 hard drives, by the time the 8 MHz ARM2 from Acorn
was reading a 56 MB Rodime, it was the drive which couldn't keep up so
executables were stored compressed on disk so the CPU had something to
do, uncompressing the sector's content, while it waited for the next
sector to arrive. :-)