1 May
2024
1 May
'24
2:47 p.m.
On Wed, May 1, 2024 at 5:38 AM Paul Berger via cctalk
<cctalk(a)classiccmp.org> wrote:
As Mike said there are two models 9114A and 9114B, they are functionally
equivalent, however the B model uses a 1/2 high drive mechanism and I
believe there are changes to the controller as well, but I have only
seen the inside of a B model.
I've got both types and not surprisingly have been inside them.
The controllers are similar in design -- the main changes are for the
different drive type and the better battery status monitor on the 'B'
-- but are not interchangeable. You probably could get it to work,
but..
The -A uses the original Sony 3.5" double-head drive. This always runs
at 600rpm, the HP one is not modified. The -B uses a later drive, also
600rpm, which shares a lot of parts with the Apple 800K drive (head
carriage, stepper motor, analogue IC...) should you need to do
repairs. The older drive has a 26 pin data cable and separate 4 pin
power cable, the later drive has a 34 pin cable for data and power
(power is on some of the odd-numbered pin, they are not all grounds as
you might expect).
The disk-inserted sensor on the -A is a spring-loaded plastic part
which interrupts the beam of a slotted optoswitch on the motor PCB
when a disk is present. Amazingly it lines up with the 'high desity
hole' in 1.4M disks. So unless you rigidly block that hole it is
likely the drive will not detect such a disk. As others have said the
1.4M disks are higher coercivity so using them is unreliable at best.
-tony