[Gibbon1]

I remember some version of BASIC from the early 80's. You could create real multi-denominational arrays including sparse ones with any starting index(s) you wanted.

Matrix operations were first class.

[hilbert42]

I curious, can you remember which ones?

[Gibbon1]

I think it was a SDS Basic or a variant.

https://en.wikipedia.org/wiki/SDS_BASIC#MAT_commands

[hilbert42]

OK, thanks. I've not used that. The problem I had was that I learned Fortran before coming across BASIC, so converting Fortran programs was often a problem when features where missing.

[Gibbon1]

I looked again and the basic I remember was on the HP 9845B that I used for a while.

https://www.hp9845.net/9845/software/basic/

[hilbert42]

Thanks for that. I've just checked the link and will do so again in more detail.