40-Year old BASICA utility code for teaching

The rest of us had tapes.

And yes the high school computers were running MS-DOS 3.3, with two 5 1/4" drives and no hard disk.

They give you access to a lot of programming logic, they're visual, they're reactive, they're easy to learn, and maybe most importantly, the results are instant. Instead of having to try and understand data types and scope and having to run a program from scratch for every change, you can just change a value and see the result right away.

I use spreadsheets for nearly anything involving "numbers" (outside of stuff with lots and lots of data), because it's a lot less of a headache than setting up a "real" language. They're wonderful.

This BASICA.EXE is the full 79kb GW-Basic 3.22 copyright Microsoft 1983, 1984, 1985, 1986, 1987.

A different version I have been using for decades is 78kb and launches with a different text header: COMPAQ Personal Computer BASIC Version 3.31 copyright Compaq Computer Corp. 1982, 1988. Copyright Microsoft 1983, 1987.

Thought to be equivalent but doesn't say anything about GW-Basic on the Compaq one.

I use it to run a program I wrote decades ago to calculate caustic soda according to reporting standards that were already arcane at the time. And GW-Basic was the "new Basic platform" for the IBM PCs and compatibles that looked like they might be here to stay by about then, and beginning to show up in a number of offices. My code was originally written in 1980 on a Hewlett-Packard gas analyzer designed in the 1970's. Even though caustic has nothing to do with gas commodities I was so fortunate to have a benchtop Basic instrument I could do anything with, and caustic was just calculations.

Once PCs got more powerful and proliferated I waited a few more years before converting caustic code from HP-Basic to IBM-Basic. HP-Basic was two optional ROMs that cost $1500 you plugged into the instrument PCB. Early IBM-Basic was still ROM-based too, this is the one that was launched from DOS using the 4kb BASICA.COM (rather than basica.exe). So it's the basica.com (sometimes renamed to basica.exe !) that doesn't work when you try to run it, because it is really meant for the antique motherboard with the specific ROMs. If you have both basica.com and basica.exe in the same directory on the command line in DOS, and you type in just "BASICA" without the extension it will run the .com if present (and errorfail with Incorrect DOS Version) rather than the full executable.

In the late '80's once it looked like GW-Basic had good penetration, made the final tweaks to my code and ran it under DOS 5, DOS 6. Booted Win3.x and W9x to DOS whenever, and since NT5 just works in a Windows command instance as long as you don't try a 64-bit version of Windows.

I suspect you're thinking of the Amstrad Spectrum +2 (grey, largely the same as the Sinclair ZX Spectrum 128) vs Amstrad Spectrum +2A (black, contained a +3 motherboard minus the FDD controller, and less compatible with external peripherals).

It seems like finding this version took at least half a miracle, so I feel like the potential and probably not too effortful reorganization of the repo to accommodate another is a problem worth leaving to be solved only once it's known to be worth taking the trouble.

For that matter, given manual reconciliation of two versions of very old, not previously version-controlled code would almost certainly be required anyway, the additional friction imposed by this repo structure very likely is net neutral in any case.