Early IBM "Small" Hard disk drives

[tinkers3]

Both the 62GV and the 62PC were designed at IBM Hursley and build at IBM Havant Hampshire in the early 70's, although I believe some were build state-side. It should have on the label where it was manufactured.
I worked on the test line for the 62GV between 1974-1976 (IBM 1130's were used as test stations).

Originally Posted by TV_Madness

Very interesting that there was a variant of the 62PC that used fixed heads on one platter. Presumably this was to aid in retrieval of "hot" blocks of data or information that was frequently required

The fixed-heads were used to dump the system memory contents in the event of a power failure. There was just enough time to do this.

I've uploaded two pictures , the one with the queen was December 1974 visit.

[Maarten]

Not quite useless. The knowledge once gained by IBM is still in use in Hitachi drives, and through licenses probably in many others as well. For example servo tracks and voice coil actuators became mainstream in the early 1990's, other inventions will have inevitably led to more new inventions. I think GMR heads were pioneered by IBM as well, as was perpendicular writing/reading.

[TV_Madness]

Those pictures are amazing. Thank you for sharing these. What a rare treat to see this kind of hardware on the production line (albeit very near the end!). A double bonus to see the queen on visit also. What was this visit in aid of?

A real piece of history.

Even more interesting to see 1130s being used as test stations.

Thanks for clarifying the purpose of the fixed heads on the 62PC also. Presumably the logic was supplied with enough power for just long enough to allow for a complete memory dump before total loss of power.

Both drives that I own were manufactured in Rochester US.

Kind Regards

Matt

[tinkers3]

Originally Posted by TV_Madness

A double bonus to see the queen on visit also. What was this visit in aid of?

I think it was 'Queen's award for industry' later became 'The Queen's Awards for Export and Technology'.

What a rare treat to see this kind of hardware on the production line (albeit very near the end!).

Yes the other pic was towards the end (field returns repair only) the 62GV was
send back into the field as a FRU E.T.N (Equivalent to New) it would have a orange label.
By the time that photo was taken I moved on to testing the 3791 communications controllers with the wonderful Lynx line printer on top .

However the 62PC I never worked on, its was still in development/post production. The 62PC disc drive was in similar vein to the 62GV.

If you manage to power it up. It should Home and Ready itself, waiting commands, which I've long forgotten.

Matt, did you work at Havant?
good luck John.

[TV_Madness]

Hi John

No I didn't work at Havant I'm afraid. I can remember when it was still running as an IBM plant however. I do work in IT though, just not for IBM

I found in the documentation (which I have taken from both the S/34 Maintenance manual and the full documentation for the 62PC itself) that the drive should carry out a calibration and home itself also as you say. To get that far would be great however I'm going to need to find a suitable power source for the drive.

The power supply needs to provide the following:

+24V
+12V
-12V
+5V
-4V

It looks as though the startup sequence is quite involved, with the drive reporting several factors back to the power supply itself (for example, whether the spindle brake is applied or not) prior to carrying the home procedure and readying the drive. I need to do a bit more research, however I can't see these signals being anything that complex. Possibly just a high or low voltage on the relevant lines.

There are two that I can see on the diagram for the card cage interconnects. "Power Good" and "Brake Applied".

Any ideas what the "Trimmer Board" is for? It appears on the documentation as a simple, small outboard PCB, mounted to the disk enclosure casting with space for 4 1/4 watt resistors on it wired in parallel. One drive that I have has three resistors installed on it with one vacant location, whilst the other only has two with the other two locations unoccupied.

All the best

Matt

[tinkers3]

Very sorry Matt, but never worked on (Piccolo) 62PC. Remember the test
line, full of 19" racks etc, but not much help.

The brake on the motor worked the same way as 62GV. Designed the stop the motor as quickly as possible in order that the heads land on the disc correctly.
The brake is released just before motor has AC (110VAC in your case) applied.
I think the brake is 24VDC but don't quote me on that
I imagine the mult-rail PSU will require lots of ampere.

I would leave the trim pots alone, they're factory set.
On the 62GV the trim pots were never adjusted.

If I remember more (it's been long time) I'll let you know.

John