Comment by VogonPoetry

Now that I've been recalling more memories of this, I do remember there being encoding or "escaped" character issues - particularly with brackets and parentheses.

There was another device between the BBC Micro and the "Versa Braille" unit. The interposing unit was a matrix switch that could multiplex between different serial devices - I now suspect it might also have been doing some character escaping / translation.

For those not familiar with Braille, it uses a 2x3 array (6 bits) to encode everything. The "standard" (ahem, by country) Braille encodings are super-sub-optimal for pretty much any programming language or mathematics.

After a bit of (me)memory refresh, in "standard" Braille you only get ( and ) - and they both encode to the same 2x3 pattern! So in Braille ()() and (()) would "read" as the same thing.

I now understand why you were asking about the software used. I do not recall how we completely worked this out. We had to have added some sort of convention for scoping.

I now also remember that the Braille terminal aggressively compressed whitespace. My friend liked to use (physical) touch to build a picture, but it was not easy to send spatial / line-by-line information to the Braille terminal.

Being able to rely on spatial information has always stuck with me. It is for this reason I've always had a bias against Python, it is one of the few languages that depends on precise whitespace for statement syntax / scope.