Re:Microsoft GW-Basic Interpreter Source Code
by dunham on Monday March 07, 2022 @12:43PM
(#30590902)
I had an obscure machine ("Interact") in the early 80's that had an 8080, 16 kb of memory, and a cassette drive. There was an assembler for it. If I remember right, you read the editor from tape, edit and save your file, then read the assembler from tape, it reads the tape with your code and then writes the output to tape.
I have no idea what the people ("Micro Video") producing software for this thing did, but I can't imagine they used this on-machine assembler.
(The tape loading mechanism was basically blocks of address + data. They put loading screens on the tapes by populating video memory first.)
https://www.filfre.net/2013/03/the-top-of-its-game/
which used virtual machine technology to deliver games developed on a Decsystem 20 to many different kinds of Micro.
When Microsoft BASIC came out in 1976 it was rare for a micro to fill out the 16-bit address space with a full 64k. I had a TRS-80 Color Computer which ran a multitasking operating system
https://en.wikipedia.org/wiki/OS-9
With 64k of RAM I wrote a FORTH interpreter that ran under OS-9 with a good standard library in about 3000 lines of assembly. OS-9 looked a lot like UNIX or VMS. Dev tools in 1984 were good enough that writing a BASIC interpreter on a micro in assembly would have been straightforward, I'm sure you could on a C-64.
No way you could do that on the base configuration Altair that Microsoft BASIC originally targeted.
The first time I used emulation was circa 1987 when I developed a BASIC program for a high school teacher who had a Z-80 based CP/M system on my generic 286 machine... Even then there was a CP/M emulator for the 286 which could destroy any Z-80 machine on the market -- even though the protected mode of the 286 was as "brain damaged" as Bill Gates said it was, the raw performance of the 286 was the beginning of the end for the 6502, 68--, 68---, Z80 and all the other architectures.