Tandata P.A.

The Tandata P.A. Story

Tandata Marketing Ltd. were known for creating low cost Prestel Video Terminals and Modems. By 1984, they were luring in engineers from the declining sister company Tangerine Computer Systems with the opportunity to create a brand new microcomputer - codenamed Minerva.

Minerva was a machine for professional users with a focus on personal management and productivity. The machine was in development for two years and released in early 1986 as the Tandata P.A. - and Personal Assistant was very apt. You could log onto Prestel and view your stocks, manage your bank account and check the news. You could store your contacts and call them with a press of a button using the built in speakerphone. Manage your finances with the spreadsheet in ROM. The machine is highly integrated, you are not meant to run other programs, and are not exposed to the system prompt. It can be considered a thin client for access to online datastores - a cross between a terminal a full micro. It was to be portable, and in many ways was an early entry into the PDA category of machines.

In 1986, the machine went on sale with a
13" colour monitor and 64k RAM for £995

Early reviews and sales for the P.A. looked promising. Tandata needed the machine to be a success, but disaster struck after only a few months of machines being out in the wild. Tandata did not provide external storage solutions, relying on the internal batteries to keep the machines data secure. Unfortunately an issue was causing machines to crash, requiring a cold boot, losing all user stored data. This issue was later identified as a faulty ROM socket, but by the time this was fixed the perception and momentum of the machine had suffered, and other machines were encroaching on the market.

This message was found etched in Rom, and serves as its epitaph:

Resetting machine, All data Lost.
Very, very Sorry

The ROM socket issue was fixed, and a Tape backup option was added to the operating system, but it was sadly too little too late. AB Microelectronics, the company that built the machine, bought the rights to the computer alongside most of Tandatas assets in 1989.

The P.A. ceased production in 1989. It is not publicly known how many were sold.

Read more at BinaryDinosaurs.co.uk

Machine Technical Specs

  • CPU: NEC V20, 4.7Mhz 8088 compatible chip.
  • Graphics: EF9345P 8bit, RF + RGB
  • 16 bit CPU, 8 bit Bus
  • Built-in 2 Column LCD display*
  • Battery Backup*
  • Tandata 13 inch monitor
  • Parallel Centronics Printer Port
Input / Output
  • UK Telephone in / out
  • RGB (Scart) 8 Pin Din
  • Tape / Video 7 Pin Din
  • Power 4 Pin Din
  • TV RF Output
  • IO Expansion 20 Pin Header
  • RS232 DB-25
  • Centronics Printer 20 Pin Header
  • External Modem 16 Pin Header
  • Phone Book
  • Notebook
  • Data Communications
  • Calendar
  • Spread Sheet
  • Calculator
  • Electronic Mail
  • Files
  • System Management
Screen Modes
  • TTY
  • Prestel
  • Prestel IP
  • P.A.
  • VT100
  • 3270
  • Teletext / Travel*
  • NCR 7900
Modem Modes
  • 300/300 (V21)
  • 1200/75 (V23)
  • 1200 H-D (V23)
  • 4800 H-D (external only)
  • 4800/75 (external only)
  • 300/300 (BELL 103)
Modem Support
  • Internal modem (VT-100)
  • External modem
  • RS-232C port modem

* The particular machine in this collection is an unusual screen-less version of the P.A. It is a cost-reduced model made for Hogg Robinson Travel Agents. The portable features were removed, so no included battery or 2 column LCD screen. The keyboard layout is slightly altered, and it contains a unique ROM set which includes a special mode for use by the Travel Agents internally to make bookings and enquiries.

This page is under construction.

Ver: PA %-3d1.3B/%02x-HRT 13
Created on :-
Not for General Release.

This machine has not yet been powered up. I am looking for pinouts for the IO and power connector. Please get in touch if you have any further information.

Tandata P.A Teardown

When I first got hold of this machine several years ago it was clear it had been used heavily in a prior life.

Scrubbed up nicely. The key legend has discoloured but it still looks great.

Tested on 14th December 1988. Not sure if this is pre sale or post return. The cover here is a useful ROM access hatch.

Overview of the PCB. Access from bottom side. Nice compact layout but lots of bodges. Good condition.

ROMs are labelled HRT13 Z50-Z56. The PIA board is visible above the roms. Roms binaries have been extracted. HRT refers to Hogg Robinson Travel.

PIA removed. Connected via dual header and separate power wire.

The PIA board contains a reference to the project codename. Minerva NMOS Emulator Issue 8.

The graphics chip is extended onto a daughter board with some mysterious scrubbed out chips.

Close up of the extended video card.

Underside of video card.

Empty video dip socket.

The keyboard disconnects via flat flex type connectors but the speaker wire is soldered down.

Underside of PCB

A small foam cube takes the place of the battery. The keyboard is membrane but very solid.

The keyboard insulators are cut outs of a plastic covered instruction booklet

This insulator looks like an old keypad.

The keyboard is not a Cherry MX like the sister machine Tandata TD4000.
Key caps are dual shot injection molded. Shift, Return and Space have stabilising bars.

Sitting in front of a TD1000/4 box

The other PA units switch on by tilting the LCD screen up. This one has a simple ON switch. The blanking and retention plates over the phone jacks is a nice touch.

Need to figure out the pinout of the power connector.

The battery compartment has a working connector inside but has no battery. The foam packer suggests its never had a battery in it.

If you have any more information about Tandata or this machine, please get in touch.

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Tandata P.A.