What a weird name, but I wanted something with calculate and tron it it, so there you go…
What is it?
APRICOT is a programmable calculator. A very simple one but it’s quite effective and Turing Complete if you want that sort of thing.
Many years back I wrote what I considered my ideal BASIC – I wrote it in C and have enjoyed using it over the years. I’ve shared it and there are a few active users out there too.
I did feel that while it was a good, full-featured modern implementation of a traditional BASIC that it was a bit big. I could not even think about running it on an old (or retro) 8-bit CPU so have looked at various “Tiny” BASICs and other languages, etc. (Except Forth or Forth-like languages. I am simply not interested in these). One that caught my eye was VTL and VTL-2 which can run on a 6502 CPU in under 1KB of RAM.
Trying to port VTL-2 to my own Ruby 6502 system proved to be a little problematic – mostly due to the amount of Zero-Page required, so in the best traditions of time, ie. How Hard Can It Be? I decided I’d write my own little language.
What to write it in?
My initial thoughts were to write it in 65C02 assembly language – that might make it accessible to most folks who have 65C02 SBCs or older systems with a 65C02 CPU.
That hasn’t happened – yet.
I started in BCPL because I have a 65C816 system that can run BCPL (and edit and compile BCPL directly on-board) I thought it might be quicker to get the ideas and basics flashed out in a higher level language then hand-translate it into 6502 code.
It was quicker to get going and I had the basics going in a few hours, but being one of 2 or maybe 3 other BCPL programmers in the world, it’s not that accessible, so to make it a little more accessible, I re-wrote it in C. Currently I’m keeping the BCPL and C versions in-step with each other.
What’s in a number?
I decided that to keep things simple and in the traditions of VTL-2 and various Tiny BASICs that I’d stick to integers – specifically 32 bit signed integers. Apple Integer BASIC was only 16-bits and good enough at the time but the BBC Micro supports 32-bit integers so 32-bit it was.
Interactively it works just like an old-school calculator. There is no operator precedence as such and operators are actioned when they are entered. So 1+2*3 is 9 and not 7 as some people might expect.
How to get it?
Head over to the downloads page to get the manual and the C source code along with some examples and even a couple of games…
You will need to know how to unpack a .TGZ file and compile a C program to use it. There is a short README file there but not a lot else…
cd /tmp mkdir apricot cd apricot wget https://project-downloads.drogon.net/apricot/apricot.tgz tar xfz apricot.tgz cd apricot-c make cd ../examples ../apricot-c/apricot --- then load an example or 2 --- see the apricot.pdf for full documentation.
A short example
This is a recursive factorial function..
"Number? " ? ;F "Factorial is: " . # _ `Factorial (F = T - 1 [ T \ T ) 1] ` If T is 1 then return , - 1 ;F = T ' * T )
and this is integer square root:
` Integer Square root ` Herons Method ` Uses S ` Uses but preserves X and Y. (Q = S > 2 [ \ S ) ] X,Y, S / 2 = X S / X + X / 2 = Y 1[ Y = X S / X + X / 2 = Y Y < X ] X = S '=Y '=X S )
Is an esoteric language? I don’t know, but it is quite usable though. At least I think so!