Techie invented bits of the box he was fixing, still botched the job
- Reference: 1716190272
- News link: https://www.theregister.co.uk/2024/05/20/who_me/
- Source link:
Apologies if that bright, cheery attitude is off-putting to you. Your correspondent is experimenting with being a "Monday person" and it feels weird.
Anyway, our story this week comes from a reader we'll Regomize as "Howard" who many years ago (many, many years ago) worked with an OS kernel called MagicSix that found use in the labs at the Massachusetts Institute of Technology while he was a student. Howard had tricked an Interdata 7/32 system to use virtual memory "in a way that its designers never intended" using the OS – such was his prowess.
[1]
After Howard graduated and went on to further education, the MIT lab upgraded to an Interdata 8/32 which, you will no doubt recall, improved upon its predecessor by supporting virtual memory properly. Howard was hired as a consultant for the process of getting MagicSix working on the new machine.
[2]
[3]
What this involved was installing the OS on a disk pack on the 7/32, removing the disk pack from that machine and installing it on the 8/32, and seeing if it would run. Repeat as often as necessary until it works.
Now, you may be wondering about the term "disk pack." We here at Who, Me? certainly were. Well, this was 1978, so hard drives weren't like they are today. Disk drives of that era looked kind of like top-loading washing machines, in Howard's description, and the disks themselves were stacks of platters "that looked like eight metal LPs" he wrote – a simile that may be no less baffling to younger readers.
[4]
Thankfully he also provided a link to [5]an image of a not-dissimilar system [PDF] of the time, so you can get the idea.
[6]One bank's brilliant upgrade was another bank's crash
[7]Techie's enthusiasm for decluttering fails to spark joy
[8]Software support chap survived breaking his customer
[9]Rarest, strangest, form of Windows saved techie from moment of security madness
Moving a disk pack from one machine to another involved stopping the drive, screwing in the carrier (which would simultaneously unscrew the disks from the drive), then lifting the carrier out. There was an interlock on the lid of the drive that stopped you from opening it while the disks were in motion, for obvious reasons.
The stacks of disks were typically labelled on the top platter. The units Howard used were labelled with the MagicSix logo – an image of which he also [10]helpfully supplied .
Now, as it happened, the process of getting up and running on the 8/32 did not go as smoothly as Howard hoped it might. Many hours of shuffling disk packs from one machine to the other ensued, with many failed attempts that meant taking the disks back to the first machine. It was very frustrating.
Around three o'clock in the morning, after yet another failure to boot, Howard opened the drive on the 8/32, noting – just for a moment – "Hey, I thought this disk had a label on it. Oh well, another mystery." Then he inserted the cover of the carrier …
[11]
Next: a hellish buzzing and shards of plastic flying everywhere, as the teeth on the cover met the teeth of the disk pack and physics did the rest. It transpired that the interlock on the drive was faulty, and the reason Howard couldn't see the label was because it was still spinning at 3600rpm.
Thankfully Howard was not the only night owl at MIT, and someone was there to show him where a vacuum cleaner could be found to clean the bits of plastic out of the drive.
He did eventually get the OS working on the 8/32, by the way. And he told us "I wish I could say I learned my lesson not to work while half-asleep, but that would take another decade or two." Oh well.
Has your tired self ever made a mistake your alert self never would have? Tell on it with [12]an email to Who, Me? and we might share your tale on some future Monday.
Get our [13]Tech Resources
[1] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZksfRrZ@8a0EFENClF9WTwAAAFc&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZksfRrZ@8a0EFENClF9WTwAAAFc&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZksfRrZ@8a0EFENClF9WTwAAAFc&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZksfRrZ@8a0EFENClF9WTwAAAFc&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[5] https://d1yx3ys82bpsa0.cloudfront.net/groups/ibm-2314.pdf
[6] https://www.theregister.com/2024/05/13/who_me/
[7] https://www.theregister.com/2024/05/06/who_me/
[8] https://www.theregister.com/2024/04/29/who_me/
[9] https://www.theregister.com/2024/04/22/who_me/
[10] https://www.etsy.com/listing/1127458426/the-prisoner-logo-38mm-15-button-pin
[11] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZksfRrZ@8a0EFENClF9WTwAAAFc&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[12] mailto:whome@theregister.com
[13] https://whitepapers.theregister.com/
Same here.
I started my career in computing as an operator on a Bull DPS 9. The night shift was where we were doing most of the disk swapping because that's when the accounting packages ran.
I moved on to programming after that.
We had disc packs for the VAXen in my first role, primarily for backup purposes. One issue was if you had to search for something on the backups, as the drives didn't like being spun up too many times in a row. First time this happened the drive died and we didn't have a clue what to do other than call an engineer. All he did was reset the trip - oops! After that it didn't matter how urgent the restore was, we'd tell the requestor it would take a few hours.
Disk packs, not disc packs.
In that era, a disc was another name for a Frisbee, or a vinyl record (which is where we got Compact Disc).
Spinning rust was universally called a disk, from the days of IBM's original Winchester drives.
"Is it disc or disk?"
The indicated drive uses disks.
A CD is a compact disc.
Yeah, unless you're wearing something like an Omega Railmaster or Rolex Milgauss, best stay away from magnets. Even the ones used in knife racks can cause issues.
ICL EDS200 - a whole 200Mb on a very large multi-platter disk.
They were cumbersome, but could take quite a lot of abuse. Whenever we experienced a brake failure, the drum would spin for ages before we could take out the disk. Quickly learned a highly unofficial trick from an ICL engineer, who showed me how to spring the interlock and manually slow the drum down....
I don't ever remember seeing an interlock fail. The ICL drives used to have a circle or cross - the circle meant the drive was up to speed and ready for use, and the cross would always flash as the drive span down and go solid when it was not in use.
Fun times!
"I am not a number," ... MagicSix
If like me you were wondering about this bit of computing history [1]MagicSix OS .
The inspiration for the name of the OS apparently was the 1967-68 Patrick McGoohan (#6) ITV series The Prisoner which also made quite an impression on me at that time. I would dearly love to visit Portmeirion but I still have problems with large white balloons. :)
Be seeing you.
[1] https://gunkies.org/wiki/MagicSix
Re: "I am not a number," ... MagicSix
> visit Portmeirion but I still have problems with large white balloons
It is well worth a visit. And is just as wonderfully out of place in Wales and it appears on the screen. To avoid Rover leave just after someone else.
I was picked to babysit a GEC 4000 computer back in the 80s, in case either of the 2 normal operators were on leave. As it wasn't anything to do with my normal day job (telecoms), I was sent on an in-house training course on one of the testbeds.
As part of the training, we (there were about half dozen of us) we got to change the single platter 24in(?) disk pack of a whole 5Mb. All went OK until one guy, having uninstalled and reinstalled the pack, tried to start it up... 'ping'... oops!
The one I used (circa 1983) still had boards of magnetic core memory.
Stupid "tired operator" tricks ...
I was burning in some two dozen nodes of T-carrier gear.
After the end of the ten day burn-in period, one of the final tests was to physically pull the plugs on the redundant power supplies, and then re-insert the plug, before moving on to the next supply. Lather, rinse, repeat, first with the supplies plugged into "power A", and then the supplies plugged into "Power B". A Sun workstation logged the relevant voltages & currents, to be printed out as part of the complete verification package for each machine. I got to the end of the long line of plugs, absentmindedly noted that this plug was different from the rest & unplugged it ... only to take down the Sun box, and completely trash the drive holding the data. It's the only time I ever lost data on a CDC Wren SCSI drive ... and it invalidated the ten day burn-in results for about two million dollars worth of "must ship" gear at quarter end.
I shouldered the blame, as I had pointed out to my Boss that having the Sun plugged into the test power bus was probably not a very good idea. All I could do is claim exhaustion, working a couple weeks of fourteen hour days because Sales had over-sold production capability and for some reason TheBoard decided we had to make the projected sales figures. Fortunately, my Boss managed to cover my ass & I kept the job. Daft thing is that I wasn't even part of the QA group that managed the burn-in, I was only roped in to help because of a lack of hands ...
Split disc
At one of my jobs we had a Singer System Ten which had 2 washing machine disc drives which boasted split discs - models 41 and 42. The bottom half of the disc pack (2 or 3 platters) was fixed in the drive, and the top half was removable so you could put different top halves on (making sure they were aligned with the tiny locating pin). Very useful for backups. Of course if the top half wasn't exactly located and you managed to remove the lid then yes, a head crash.
experimenting with being a "Monday person" and it feels weird
It's a public holiday here in France, so a croissant and a nice mug of Tetley and no alarm to get up to. This is how Mondays should be.
(and Tuesdays, and Wednesdays......)
Oh I remember top loading disc drives well, and replacing heads after disc crashes. (Is it disc or disk?) Initially drives on ICL systems and them CDC drives in Calma CAD/CAm systems.
Also wondering why it wasn't as late as I though it was when I checked the time on my watch. The drives had very powerful magnets which didn't play nice with a Seiko watch, it was never the same afterwards.