Thursday, May 11, 2017

Building a 68000 Single Board Computer - Dr. Dobb's Toolbook of 68000 Programming

As part of my 68000 retrocomputing work, I've been collecting some old books on 68000 programming. One book that I have been searching for some time is Dr. Dobb's Toolbook of 68000 Programming. I was recently able to acquire a copy.

It is a collection of articles on the 68000 that were originally published in Dr. Dobb's Journal. Most of them were added or updated for publication in the book. It is an interesting collection of articles, ranging from an introduction to the 68000 family to some Forth implementations and 68000 assemblers, and some small programs.

Gordon Brandly's Tiny Basic, which I have earlier run on the TS2 board, is included.

Some of the articles are quite relevant to my recent work on the TS2 board. There is one on the TUTOR monitor program and another and on bringing up a new 68K board by getting it to freerun.

Overall, it makes for an interesting read. I even know one of the authors -- someone who did some consulting work (not 68000 related) where I was once employed.

This particular copy came from the University of Hertfordshire in England and contains the original library markings and card.

While some of the articles have very large software listings (like a 68000 assembler written in Modula-2), four of the articles were relatively small self-contained programs: I entered the source code for them and put the code up on my github account.

I successfully assembled them with the VASM assembler and ran them on my TS2 board under the TUTOR monitor. They all seemed to work flawlessly (with the exception of one that is not a complete self-contained program).

It was quite straightforward to run them under TUTOR, I added a small main routine with a JSR followed by a TRAP #14 to return to TUTOR after execution. From TUTOR I could set register values to fill in the parameters and the look at the values returned.

Now I'm debating whether to type in 88 pages of Modula-2 source code for an assembler - I don't think I can find a suitable compiler.


Unknown said...

Back in the early nineties I built a 68k computer. I typed Tiny Basic in, never got around to typing the assembler in.

There's also Patrick Jaulent's book, which covers the hardware side -- as does Horrible & Hill, a little bit.

I should at least make a picture of my library shelf appear on my website.

Unknown said...

But! All is not lost! :-)

I found a file I downloaded from back in 1994.

(And I'm going to highjack your blog, Jeff, and ask if anyone reads this and they have an archive of either bode or nyquist, please contact me, I'd like to mirror / archive it -- thanks)

Anyway, to save you some typing: