Fortran Compiler for Sinclair ZX Spectrum rediscovered after 40 years
It started with a tweet
While basking in some geek nostalgia on twitter, I discovered that my first ever microcomputer, the Sinclair Spectrum, once had a Fortran compiler
However, that compiler was seemingly lost to history and was declared Missing in Action on World of Spectrum.
A few of us on Twitter enjoyed reading the 1987 review of this Fortran Compiler but since no one had ever uploaded an image of it to the internet, it seemed that we’d never get the chance to play with it ourselves.
I never thought it would come to this
One of the benefits of 5000+ followers on Twitter is that there’s usually someone who knows something interesting about whatever you happen to tweet about and in this instance, that somebody was my fellow Fellow of the Software Sustainability Institute, Barry Rowlingson. Barry was fairly sure that he’d recently packed a copy of the Mira Fortran Compiler away in his loft and was blissfully unaware of the fact that he was sitting on a missing piece of microcomputing history!
He was right! He did have it in the attic…and members of the community considered it valuable.
As Barry mentioned in his tweet, converting a 40 year old cassette to an archivable .tzx format is a process that could result in permanent failure. The attempt on side 1 of the cassette didn’t work but fortunately, side 2 is where the action was!
It turns out that everything worked perfectly. On loading it into a Spectrum emulator, Barry could enter and compile Fortran on this platform for the first time in decades! Here is the source code for a program that computes prime numbers
Here it is running
and here we have Barry giving the sales pitch on the advanced functionality of this compiler :)
How to get the compiler
Barry has made the compiler, and scans of the documentation, available at https://gitlab.com/b-rowlingson/mirafortran