1046 Brands 3087 Models 20094 Galleries 12381 Typefaces 6273 Patents
1969 IBM Magnetic Tape Selectric Composer Serial # 42538 1969 IBM Magnetic Tape Selectric Composer typewriter, Serial # 42538 Erik Bruchez's 1969 IBM Magnetic Tape Selectric Composer typewriter. 2024-03-28 From the Virtual Typewriter Collection of Erik Bruchez: 1969 IBM Magnetic Tape Selectric Composer Serial # 42538 This is a first on TWDB, and in fact this might well be the only known surviving Magnetic Tape Selectric Composer in existence!

This is a full IBM Magnetic Tape Selectric Composer, consisting of:

- the modified Selectric Composer
- the Composer Console desk
- the Selectric Composer MT/Reader

A 1967 document quotes the MT/SC at $16,550, which is about $150,000 in 2024 US dollars. In ads of the days, IBM boasted about the MT/ST being a $10,000 typewriter. So the MT/SC was about 50% more expensive than that, and then you needed an MT/SR or an MT/ST alongside it!

Amazingly, a complete binder with service schematics is present. The binder was meant to be stored in the MT unit. There is also a complete service record, showing that the machine was put in service in 1969, and used until at least 1978.

The desk contains most of the electronics. The magnetic tape reader features two tapes, with the ability to read from one or the other. The desk/console also has a control panel with buttons and visual indicators. This is built into the desk at that specific angle, so that it can face the user sitting at the Composer.

The electronics even feature some core memory! This is probably necessary because the machine must be able to process and justify a line of text before being able to send it to the Composer proper for output. This is all fascinating, and will be a lot of work to fully understand.

Unlike the MT/ST, which has logic implemented with relays, the Composer Console desk contains electronics which use boards plugging into a wire-wrapped backplane. There is also a large power supply.

Two tapes were present in the MT Reader unit.

This unit is meant to be used alongside this Magnetic Tape Selectric Recorder:

https://typewriterdatabase.com/1969-ibm-magnetic-tape-selectric-recorder.22539.typewriter

Needless to say, restoring this would be a huge undertaking: from the Composer, to the tape reader unit, to the electronics in the desk. The good news is that there are maintenance schematics for the electronics! This was not the case with later systems like the Mag Card and Mag Card II, where the planar (electronics) was just considered a part to exchange if faulty. I do not plan to fix this immediately, but I do want to slowly learn about the system first.

1969 IBM Magnetic Tape Selectric Composer #42538

Status: My Collection
Hunter: Erik Bruchez (ebruchez)
Created: 03-25-2024 at 08:19PM
Last Edit: 03-28-2024 at 10:31AM


Description:

This is a first on TWDB, and in fact this might well be the only known surviving Magnetic Tape Selectric Composer in existence!

This is a full IBM Magnetic Tape Selectric Composer, consisting of:

- the modified Selectric Composer
- the Composer Console desk
- the Selectric Composer MT/Reader

A 1967 document quotes the MT/SC at $16,550, which is about $150,000 in 2024 US dollars. In ads of the days, IBM boasted about the MT/ST being a $10,000 typewriter. So the MT/SC was about 50% more expensive than that, and then you needed an MT/SR or an MT/ST alongside it!

Amazingly, a complete binder with service schematics is present. The binder was meant to be stored in the MT unit. There is also a complete service record, showing that the machine was put in service in 1969, and used until at least 1978.

The desk contains most of the electronics. The magnetic tape reader features two tapes, with the ability to read from one or the other. The desk/console also has a control panel with buttons and visual indicators. This is built into the desk at that specific angle, so that it can face the user sitting at the Composer.

The electronics even feature some core memory! This is probably necessary because the machine must be able to process and justify a line of text before being able to send it to the Composer proper for output. This is all fascinating, and will be a lot of work to fully understand.

Unlike the MT/ST, which has logic implemented with relays, the Composer Console desk contains electronics which use boards plugging into a wire-wrapped backplane. There is also a large power supply.

Two tapes were present in the MT Reader unit.

This unit is meant to be used alongside this Magnetic Tape Selectric Recorder:

https://typewriterdatabase.com/1969-ibm-magnetic-tape-selectric-recorder.22539.typewriter

Needless to say, restoring this would be a huge undertaking: from the Composer, to the tape reader unit, to the electronics in the desk. The good news is that there are maintenance schematics for the electronics! This was not the case with later systems like the Mag Card and Mag Card II, where the planar (electronics) was just considered a part to exchange if faulty. I do not plan to fix this immediately, but I do want to slowly learn about the system first.

Typeface Specimen:

Links:

Photos:



























































This exact setup from an IBM marketing photo of the time (Norsk Teknisk Museum - https://digitaltmuseum.org/011015239419/7-0-ibm-op-fotografier CC BY-SA 4.0)
This exact setup from an IBM marketing photo of the time (Norsk Teknisk Museum - https://digitaltmuseum.org/011015239419/7-0-ibm-op-fotografier CC BY-SA 4.0)

Hunter: Erik Bruchez (ebruchez)

Erik Bruchez's Typewriter Galleries [ My Collection ] [ My Sightings ]

Status: Typewriter Hunter
Points: 10734

I started collecting my first pre-WW2 standard typewriters in 2017. Since then I have added a few machines to my collection, which now ranges from the 1890s to the 1980s. As of 2020, I have more big standard (desktop) typewriters than portables, and a few standard electrics.



RESEARCH NOTE: When researching the IBM Magnetic Tape Selectric Composer on a computer with lots of screen real estate, you may find that launching the IBM Serial Number page and the IBM Magnetic Tape Selectric Composer By Model/Year/Serial page in new browser windows can give you interesting perspectives on changes throughout the model series.