Talk:Early IBM disk storage

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Contents 1 Winchester Blvd 2 Sizes 3 Number of platters 4 3380 5 Tub file? 6 2311 rememberances

[edit] Winchester Blvd

It was my (admittedly undocumented) impression that the Winchester Disk was named not for the Winchester Rifle, but for the location of the IBM office on Winchester Blvd in San Jose. Perhaps this is an urban legend but I recall hearing it many years ago. Jim Bowery 23:35, 19 September 2006 (UTC)

[edit] Sizes

Drive sizes are listed as "decimal digits" and "characters". What are they in bytes or bits or octets? - Omegatron 15:41, May 13, 2005 (UTC)

And make sure to remember the difference between megabytes and mebibytes.

decimal digits were either 4 or 5 bits plus 1 parity bit; characters were either 6 (BCDIC) or 8 (EBCDIC) bits plus 1 parity bit. -- 205.175.225.5 00:23, 18 March 2006 (UTC)

[edit] Number of platters

I used to work with these things and I'm fairly sure they had six platters not five. However the top surface of the top platter and the bottom surface of the bottom platter were not used so there were ten surfaces coated with the magnetic material, giving ten tracks per cylinder. The reason the outside surfaces were not used is that they were liable to be touched when the disk was removed from its drive. In fact operators would place their hands on the top surface to slow them down. This led at least one manufacturer to coat the top with abrasive.

Here is a photograph of the disk which shows six platters. If anything this one is even clearer. Is this enough proof to merit editing the article? --R Cornwell 13:20, 4 May 2006 (UTC)

I fixed it under 2311. The section on the 1311 had it right. --agr 19:11, 4 May 2006 (UTC)

[edit] 3380

IBM 3380 redirects here, but this article doesn't say anything about it. A netnews article I read suggests that there are still some in operation. 121a0012 19:06, 5 May 2006 (UTC)

Thanks, I've added some info.--agr 00:07, 11 May 2006 (UTC)

[edit] Tub file?

I'm not sure what is meant by "the punch card tub file used by most businesses of the time." Please elaborate.--agr 03:24, 20 September 2006 (UTC)

[edit] 2311 rememberances

The shop where I got my first operators job had a string of 4 2311s and here is what I remember about them.

One of the previous posts mentioned operators slowing them down with their hands. There were really 2 parts to a 2311, and all the disks until Winchester. There was the drive that contained the electronics, drive motors, and heads. There was also the disk pack. Storage was so expensive, thousands of dollars for one 7MB drive, that nobody thought of having all their data online and it was not necessary since everything was batch jobs. So, you would have a pack for your payroll files, one for the GL, etc. When you ran a job you would have to mount the packs that contained the data.

Push the stop button and the drive would spin down but this took forever and who has the time? When you opened the lid there was something that engaged to prevent the disk from turning. If you just opened the top on a spinning disk this would take some damage so that was out. If you just opened the top a little you could reach up under it and get your fingers on the top platter and slow it down. I don't think lawyers to sue had been invented yet.

Once it sopped you opened the top and took the top of the case, a clear plastic tub with a handle on the top, put it over the disk. Spinning the top would attach it to the top of the disk and detach the disk from the drive. You lifted it up and stuck the bottom on to keep some of the crud out.

I don't see how any PC person can conceive of the size of one of these things. The pack was about 16 inches in diameter by about 6 inches high. In this massive area the drive could write 100 or 200 tracks (I think the 2311 had 100 and the 2314 had 200. the 2314 also doubled the number of platters) In fact when you were doing a backup of the drive you could tell how far you had gotten by going over to the drive and looking down through the glass top. The arm holding the heads came straight out from the side and on to of it was a scale with the tracks marked. You could literally look down and see what track you were up to.

Now, everybody knows that the heads are moved by that nice clean voice coil. Not the 2311s. They were hydraulic. Nice little pump, hoses, pistons, etc. In fact one of our 2311s had a small leak and when the CE came in to do preventative maintenance (There was so much mechanical stuff associated with a computer that every week the guy form IBM came and spend a few hours trying to fix things before they broke.) he would get a hand full of the little bits from the card punch and literally put them inside the disk drive to soak up the oil. —The preceding unsigned comment was added by P7willm (talk • contribs) 15:49, 22 March 2007 (UTC).