The Softy 1

Softy 1 

The information on this page is largely down to Derek at who still has his original Softy 1 and provided copies of the documentation and photos but most importantly the loan of the firmware EPROM and character generator PROM for copying.

The Softy 1 was designed and manufactured by G P Industrial Electronics (Plymouth) in the 1970's.  Its primary function was as an EPROM Programmer but it was also intended to be used as an industrial controller or as the development system for other products.  It was aimed at the professional and hobbyist markets and could be purchased either complete or as a kit.  It is of particular interest because it is capable of programming 3-rail EPROMs.

The core of the machine employs a National Semiconductors INS8060 Processor (SC/MP) and INS8154 RAM and I/O IC, along the lines of the Sinclair MK14 with a similar keypad but rather than an LED display output is to a TV.

It can read and program TMS2704, TMS 2708 or TMS 2716 3-rail EPROMs, it is not (in its standard configuration) capable of programming or reading single rail EPROMs - they would be damaged if plugged in.

Softy 1 includes a cassette interface 'Transwift' which can be used to store data.

A 'Conversion Card' was available that enabled programming of 2508, 2758, 2516 (Intel 2716) and 2532 EPROMs.


The Softy 1 Manual covers not only the construction and operation of the device but includes sections on SC/MP programming, interfacing and program listings for adding a printer and a simple interpretative language.  It also includes a schematic though its not very easy to follow as most of the IC pins are unlabeled.


Softy 1 firmware is in a 2708 EPROM.  I have extracted and disassembled the code so that it can be reassembled using the SB-Assembler (

Character PROM (IC9)

The characters on the screen are created using fonts stored in a fusible link PROM (IC9), I have extracted the data from the PROM and also written a python program that displays the contents:

and the python program and output

Memory Map


I have made a replica Softy 1 details of which can be found here:


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