The Assembly Line

written by Matthew Reed

“The Assembly Line” was a column about assembly language programming which first appeared in the April 1980 issue of 80 Microcomputing. It was written by William Barden, well known for his books about assembly language such as the Z80 Microcomputer Handbook, TRS-80 Assembly Language Programming, and Programming Techniques for Level II BASIC. The first “Assembly Line” column began with these words:

This is the first of what I hope will be many columns devoted to TRS-80 assembly language programming. Judging from articles I’ve read and comments I’ve heard at users' groups, many of you are interested in assembly language. I’ll provide tutorial material on the more difficult aspects of assembly-language routines that you can use with BASIC programs or other assembly-language code.

“The Assembly Line” focused on Z80 assembly language for the TRS-80 Model I and 6809 assembly language for the TRS-80 Color Computer. Barden quite liked the 6809, describing it as having “a nice instruction set built along classical lines,” and featured more 6809 coverage as the column progressed.

The columns dealt with many generic assembly language programming topics, including look-up tables, interrupts, creating relocatable code, and how to disassemble programs. William Barden also covered many topics specific to the TRS-80, such as using TRS-80 graphics, accessing disk files with TRSDOS, and examinations of different debugging tools. He also featured four different “Great Assembly Language” contests, in which readers could send in their solutions to assembly language programming puzzles. Contest winners received prizes of books.

The July 1981 column provided an excellent overview of programming the TRS-80 disk controller. This column was frequently cited because information about programming the disk controller was rather hard to find.

William Barden had a very engaging writing style which helped draw in readers and make the topics understandable despite the very technical subject matter. I always liked this opening to one of his columns:

Towards the beginning of each month, my wife notices subtle changes in me—my beard grows faster, my eyebrows start to get bushy, and I snarl at her in wolf-like tones. Yes, it’s “Assembly Line” column time once again.

The final “Assembly Line” column was in the November 1981 issue of 80 Microcomputing. Under the subtitle “It’s the End of Him, But Just the Beginning for Us,” he provided this explanation:

A favorite line from a Grade C monster movie… Yes, “Assembly Line” readers, this is my last column. I’ve enjoyed writing very much, and sincerely appreciate the many letters I’ve received (except for the one from Manny, who sent me a 250-page listing with a demand to “straighten out his eight-dimensional string sort”).

“The Assembly Line” was replaced the following month by “Soft Bits,” a column by Roger Fuller which covered similar topics.

Categories: Magazines


Stephen Wright says:

Good job with your look at The Assembly Line. I once had occasion to write to Mr. Barden with a question about one of his books. He responded with a very pleasant letter to answer my question. A true gentleman and I wish there were more books like his available today.

David Sutherland says:

Great articles Matthew. I am starting to become a regular reader. Don’t know why I didn’t see this site for so long.

Jonathan Abbey says:

Yup. Mr. Barden taught me assembly language by way of his fantastic TRS-80 Assembly book. I’ve very fond memories of it, all these years later.