|Re: HP-IL (71B) with 9114B QUESTION|
Message #8 Posted by Tony Duell on 20 Aug 2001, 5:18 p.m.,
in response to message #7 by Steve (Australia)
The grease-turned-to-glue problem mainly occurs in the older full-height 3.5" Sony drives, used in the 9114A, 9133, 9121/2/3, etc. A little latch in the disk holder doesn't engage and the disk holder doesn't stay in the 'up' position. The result, if you are unlucky is a ripped-off upper head (and you get the 'fun' of replacing the head carriage and re-aligning it -- I've done this once in a 9133, and it was not
that hard given a 'scope and alignment floppy. But it's easier to replace the grease before this occurs, even though to do it properly you have to dismantle a large part of the drive (I can post the step-by-step procedure if anyone's interested).
The 9114B uses a later Sony drive mechanism, half height (with an overgrown front panel). It's similar to the Apple 800K drive (used in the Mac+, etc), to the extent that many parts (stepper, head carriage, motor driver chips, analogue ASIC, etc) can be interchanged between the 2 types of drive. An old Apple Mac+ drive is one of the best sources of spares for
the 9114B. I've never seen one of those with a sticky eject problem, and I don't think it's likely to happen (the mechanism is totally different, so the same problem can't really occur).
A few points, though. Even though the 9114B drive has a 34 pin cable, don't use a PC type of drive in that unit. For one thing, the pinout is non-standard (on a PC, all odd numbered pins are ground, on the 9114B, there's +5V and +12V on some of them -- there's no separate power connector). For another thing, the 9114
drives (both versions) spin at 600rpm -- twice as fast as a PC drive, and thus the controller is set up for a double-speed data rate. Realigning the cotnroller for a normal PC drive is possible, but not trivial (don't attempt to fiddle unless you have the WD279x data sheets and understand them!).
When I said the drive mecahnism in the 9114B was similar to that in the Mac+, I was not joking. There's even space on the PCB and holes in the main chassis for a motorised eject option (although the 9114B controller wouldn't handle it even if it was installed). About the only significant difference is the digital ASIC, because the Apple Mac disk interface is just plain strange...