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This article was contributed by Keith 'the Engineer'.


Many moons ago I was an engineer working for our software house which was developing accounting hotal and factory systems.

We became OEM's for TI and sold a few mainly into medium sized businesses.

I maintained TI 990-10 990-12 and various professional computers as TI called their PC clone a desktop type and a portable.

Disk drives were a variation on CDC CMD of 80MB or 96Mb.

Terminals were 911VDT and the fibre optic type which number escapes me.

We had several large systems installed which included remote cluster controllers and leased lines supporting 20 or so terminals in house and 4 remotes we also had v32 modems at £1000/pair which we could online support 1200 baud full duplex ...

Hotel systems were smaller but I developed special devices inc memory key drivers for hotel keys using the datakey devices mannesmann tally guiloutine printers to allow self service checkouts remote printers for food ordering.

Overall they were reliable the first ones were discrete cpus developing into MPU's with the later ram was 192k per board i think VDT terminals were 4 per board serial IO boards were half width and we used to emulate these for our devices making them 8 bit plus parity using the diagnostic bit to allow non supported comms types.

We ran one into the late 1990's as a development machine running analysis tools until drive failure killed it.

Overall a good but expensive machine a CDC drive was £18,000 when I could buy the same unit for £4.000 just the interface cable was different.

Printers were 810 TI which survive today in warehouses printing NCR forms these were reliable except for the tach which drops pulses and the head gradually creeps to one side.

Date : Unknown

This exhibit has a reference ID of CH40304. Please quote this reference ID in any communication with the Centre for Computing History.

Memories - TI990 - An Engineer's View

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