10 Aug
2005
10 Aug
'05
6:16 p.m.
page 1-1 of the RK11-C manual
(RK11-C_manual1971.pdf)
"The high-density option provides a choice of either
the RK03 Diablo Disk Drive Unit or the RK05 DECpack
Unit, both utilizing the RK03-KA, IBM Type 2315 12
sector high-density disk cartridge. The low-density
option provides a choice of either the RK02 Diablo
Disk Drive Unit or the RK04 DECKpack Unit, both
utilizing the RK02-KA IBM Type 2315 12-sector low
density disk cartridge".
low density is 12 256 byte sectors (1100 bpi)
high density is 12 512 byte sectors (2200 bpi)
both are 203 cyls, 2 tracks.
I can't imagine there were many RK04's made..
And not all controllers supported them. The RK11-C has a bit of logic on
it to provide a half-freqeuncy clock for the RK02/RK04 mode (it's half
the bit densirt round the track). AFAIK the RK11-D doesn't.
The RK11-C would appear to support RK02, RK03, RK04, RK05 using 1-of-n
selects. The RK11-D would appear to be RK05 _only_ -- it requires a drive
that supports binary selects (which rules out the 02/03) and it doesn't
do low density.
I've never seen an RK04 or any manuals for it.
-tony