23 Mar
2025
23 Mar
'25
6:40 p.m.
On Sun, Mar 23, 2025 at 6:30 PM Ali <cctalk(a)ibm51xx.net> wrote:
A = 40 cylinder single head
B = 40 cylinder double head
E = 80 cylinder single head
F = 80 cylnder double head.
Very few machines used an 80 cylinder single head drive, and I suspect
the -F wasn't much more expensive anyway. So the -E model is not at
all common
(I believe C and D were reserved for 77 cylinder (8"?) drives, G is 80
cylinder double head, high density (360RPM? -- 1.2MByte), and H is 80
cylinder double head high density (1.4MByte))
-tony
I don't have any spares for these drives. As
I said earlier you need
to know the complete model number to get the right drive to take parts
from. It does have to be a -B (double head, 48tpi). The -A is
single-head, the -E (very rare!) and -F are the single and double head
96tpi versions, so the head is designed for a narrower track.
What is so special/rare about the E? I have only seen the -B and -F variants used in most
machines.