Minor Tektronix success story.

From: Philip.Belben_at_powertech.co.uk <(Philip.Belben_at_powertech.co.uk)>
Date: Fri Aug 21 07:55:45 1998

>>Could someone please enlighten me... What, pray, is FLEX?
>
> For years, it was *THE* disk operating system if you had a 6800/6802
> based system. Originally written in the late 70's, it powered the
> majority of the SS-50 computers until the 6809 came out. Then came
> FLEX/09, StarDOS, UniFLEX, OS/9. . . .

Thanks. I wonder why I'd never heard of it.

> It was a bit limited, but it was small enough to fit within the 6800's 64K
> address space, with *plenty* of room to spare!

The 4052 has a 128K address space - separate 64k spaces for code and
data. That said, there are ways of running code in the data space and
accessing data in the code space.

> Well, yeah, but still faster then 1Mc (or 800kc if you didn't modify
> the cpu board).

Yes, much.

>>I must do some more research into the relationship between 4052 and 6800
>>instruction sets.
>
> Yes. How the implemented the microcode would be of particular interest.

The service manuals tell you a lot about how the microcode is executed,
but little about what's in there. Similarly there is a list of
instruction mnemonics and addressing modes against opcodes, and even an
explanation of how the addressing modes work, but nothing to tell you
what the instructions do, let alone anything in the way of ROM listings.
One day I might get around to decompiling the microcode...

Philip.
Received on Fri Aug 21 1998 - 07:55:45 BST