IBM Confidential: System/360 File Organization [video]

https://www.youtube.com/watch?v=zokKqP0plrM

by DaiPlusPlus • 2 months ago

67 31 2 months ago

froh• 2 months ago

(1964)

a webcast about the many great benefits of the novel DASD (direct access storage device) over ISAM (index sequential access)

aka disk and tape.

16mm film

Flipchart

impeccable presentation

thx for the time machine :-)

themafia• 2 months ago

DASDs supported ISAM.

And they're not strictly just a disk. It's more like a complex multiplexing system for an array of disks. It has interesting capabilities like "channel programs" that persist to this day which allow you to send miniature programs to the disk controller to have it seek out the precise record you're looking for in one of several access modes.

IBM still provides almost the entirety of it's OS documentation online:

https://www.ibm.com/docs/en/zos-basic-skills?topic=set-what-...

ErroneousBosh• 2 months ago

send miniature programs to the disk controller to have it seek out the precise record you're looking for

A very long time ago, a guy I used to work with was porting a sales and stock control database he'd written on the Commodore PET to a PC. By then he had a 286 with a 20MB hard disk and 2MB of RAM to play with - whopping stuff! - but his original program would assemble up a query routine, and transmit it to the 6502 in the PET disk drives over HPIB. Then it would chunter away discovering the records it needed to construct a reply while the host computer could continue working as normal. It was absolutely genius stuff, and it made the whole system seem really responsive even though in reality it was pretty slow.

Pinus• 2 months ago

The slide transition at 6:16 took me by surprise. =)

Chap needs to have his suit jacket fixed, though... that collar gap!

p_l2• 2 months ago

ISAM in all important variants pretty much required DASDs, CKDs (Count Key Data) in fact as opposed to FBAs (Fixed Block Access - which act like normal drives people are familiar with)

Tapes don't provide CKD interface and thus do not work with ISAM.

adrian_b6• 2 months ago

Why do you think that the presentation was done in 1964?

On Youtube there is no mention about the date.

OS/360 was announced in 1964 but it was first delivered more than a year later.

I doubt that such presentations were done about a product that no customers could use and which might still be changed until the first deliverable version.

So I believe that it is unlikely that this presentation was done earlier than 1965 and it is likely that it was not done before 1966. The first OS/360 versions were delivered in November/December 1965.

haunter3• 2 months ago

The earlier video from the series, GG46955 IBM SYSTEM/360 READ ONLY STORAGE, is dated to 1964

https://www.youtube.com/watch?v=gcc_SAy-I80

cocodill• 2 months ago

Hairstyles used to be better than they are today.

bitwize• 2 months ago

Great video for the month of "Mayframe"!

haeseong• 2 months ago

The channel program concept described here, where I/O operations are offloaded to a dedicated controller with its own instruction sequence, was a structural ancestor of modern asynchronous I/O and DMA architectures. The System/360 also codified the byte as exactly eight bits, a decision so foundational that it became the silent assumption underlying every computing architecture that followed.

tgv• 2 months ago

I don't think IBM's influence was that large. IBM was a world on its own. The rest had hardware from many manufacturers. If there's a single point in time where the byte got its definitive shape, I'd say it was Intel's 4004, or the 8008.

adrian_b6• 2 months ago

The calculator chip 4004 never had any relevance for computers, and it did not have "bytes".

Intel 8008 did not have anything original in its architecture, it was just a monolithic PMOS re-implementation of the CPU of the embedded computer designed for the serial terminal Datapoint 2200, which had been designed with TTL integrated circuits. All the decisions about sizes, e.g. 8-bit data and 14-bit addresses, had been done by Datapoint in 1970, not by Intel. Datapoint had chosen 8-bit bytes in order to support the recently standardized ASCII 7-bit character set (and the 8-bit IBM EBCDIC character set, if necessary), i.e. the character sets used by the computers to which such a serial terminal could be connected.

At the time when the first microprocessors were designed, during the first half of the seventies, the most important architectural influence on any new computer designs were the DEC PDP-11 minicomputers.

DEC PDP-11 used 8-bit bytes, which was a significant change from the previous DEC computers, most of which used word sizes that were a multiple of 6, like 12-bit, 18-bit or 36-bit.

DEC PDP-11 had transitioned to 8-bit bytes (in 1970) mainly due to the influence of IBM System/360. The standardization of the 7-bit ASCII code for characters, which could no longer fit inside 6-bit bytes, has contributed to this decision, but the standardization of ASCII was itself possible only because many computer vendors had already transitioned or decided to transition to 8-bit bytes, so they could store the new ASCII characters in their bytes.

After 1967, when ASCII was standardized in a form close to the present form, after which it was also taken into international standards by ISO and CCITT, all new computer instruction-set architectures were designed with 8-bit bytes.

p_l2• 2 months ago

S/360 is what pushed 8 bit bytes to worldwide prominence.

IBM was ridiculously huge, both by actual IBM hardware, but also by clones, and manufacture of S/360-compatible systems. Even many wildly different computers often had third party interfaces to hook up S/360 channel devices, or controllers for the actual devices (it was common for channel devices to be linked like this: S/360 -> channel processor -> controller -> device-specific connections -> actual device).

Even the fact that we format code usually to 72 characters is related to 80-character standard S/360 punched card, where the remaining 8 characters were used for sorting/comment code, and why professional terminals (as opposed to things like 40 column mode on home computers) had 80 column displays.

Also, had ASCII been ready earlier, S/360 would have used ASCII as default encoding - IIRC S/360 team decided they can't wait for ASCII to be finalized and they needed to start design and making of various devices that would have to be encoding-aware, thus EBCDIC was born.

haunter3• 2 months ago

Passed away in 2012 so he saw the modern internet age

Pearson LeRoy Wood, 81, passed away April 4, 2012. He was born May 12, 1930 in Detroit, MI. A graduate of Detroit Institute of Technology, Pearson served two years in the US Army. He was employed by IBM for 37 years. He was a member of Resurrection Lutheran Church and also The American Legion, Post 67, in Cary.
Survivors are his wife, Elaine; two daughters, Diane Post (Barry) of Cary and Susan Scofield (Fred) of Wake Forest; five grandchildren; three great-grandchildren; five sisters and two brothers.

https://www.dignitymemorial.com/obituaries/cary-nc/pearson-w...

russellbeattie• 2 months ago

Amazingly, IBM is still making videos like this. You can find great videos online from them explaining the technical details of LLMs, ML, and the like [1]. The guy in this IBM clip is a progenitor of what they still do today.

I've worked most of my career in developer relations at various Big Tech (advocate, evangelist, pre-sales, etc.) which in large part entails giving presentations explaining how a company's technology works to others. It makes me wonder if the couple official company videos I've made will be viewed in 70 years by that generation's techies.

1. https://m.youtube.com/@IBMTechnology

ToddWBurgess• 2 months ago

Before watching that video all the IBM employees would have had to get together and sing songs. It was a long standing tradition at IBM that all employees at the start of the day had to get together and sing songs praising IBM and Thomas Watson. You can still find copies of the IBM song book floating around the Internet.

When my Dad started in the late 60s IBM had discontinued the morning song tradition.

Cyph0n• 2 months ago

Interesting. So that explains where the inspiration for the cult-like elements in Severance came from. The parallels between Lumon and IBM were fairly clear to me, save for this part.

morpheos137• 2 months ago

I'm interested in the program he would have used to typeset his presentation in the 1960s. Also not at all an attack but he seems to be either nervous public speaker or to have a well mananged speech impediment. Just an observation not a critique. It is fascinating IBM woukd have chosen such 'shy' person to make the presentation.

elzbardico• 2 months ago

It is not mechanically printed, those materials where hand drafted. I got some very old teachers in college during the 90s, and their hand-drawn flipcharts looked exactly like this.

Sometimes companies used to hire artists to finish this kind of material, but usually engineers at that time were pretty much capable of drafting this kind of presentation on paper, just with rulers, compasses, and the ocasional template rule.

White collar professions used to be way more embodied in the real physic world. Kids were trained on caligraphy and basic drafting techniques since elementary school.

alt219• 2 months ago

I'm not a graphic arts expert, but the lettering and charts in this presentation appear to be done by hand.

And since this was an internal IBM presentation for salesmen and engineers, the priority likely wouldn't've been on using a polished presenter, just making the information available.

youboll• 2 months ago

https://www.youtube.com/watch?v=zokKqP0plrM&t=176s

Sorry, it was stronger than me \s

IBM Confidential: System/360 File Organization [video]

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