commodore

Extending Commodore 64 BASIC

Jim Lawless
The original version of this post was published on March 16, 2014. Back in the day, I used to write machine-language subroutines for the Commodore 64 that I would then call from a main program written in BASIC. I found it easier to use BASIC as the higher-order controller over a set of ML functions that usually did things for which CBM BASIC 2.0 was not well-suited. In one case, I wrote an Xmodem file-transfer protocol handler.

How I Chose to Upgrade to a Commodore 64

Jim Lawless
In the mid-1980’s, I’d owned a used TRS-80 Model I for about a year when I had a yearning for a newer system. I only had cassette-based storage which proved to be unreliable. I had a 16K machine and I had a few games and tools for the TRS-80. I learned Z-80 assembly language and I was having a lot of fun tinkering, but that particular line of computers had met its end.

My Journey Began with BASIC

Jim Lawless
“It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration” – Edsger Dijkstra My early days of computing began in the late 1970’s. I used to go in to the Radio Shack in the mall where they would let the patrons type stuff into their display-model TRS-80. You could tell that none of the patrons were skilled in any type of computer language as the screen was filled with a line of nonsense followed by a line indicating that a syntax-error had occurred.

Computers I Have Known

Jim Lawless
Originally published on: Sat, 22 May 2010 The first computer in my household was a Radio Shack TRS-80 pocket computer that my dad owned. My brother got it for him as a birthday gift in 1980. This was essentially a calculator with a pretty nifty BASIC interpreter built in. The BASIC was not without its own personality. Although it supported arrays, I found that if I DIM’ed an array “A” and placed a value in A(2) … variable “B” would get clobbered.

Jim Butterfield : The Commodore Guru

Jim Lawless
Originally published in the Commodore Hacking (C=Hacking) electronic magazine #14, November 1996. This post has been reprinted in Commodore Free magazine and other e-magazines. Jim Butterfield passed away on June 29th, 2007 after a long battle with cancer. I grieve with the family and the legions of techies who looked upon Jim as a mentor via his articles and ongoing contact with the Commodore community. Rest in peace, Mr. Butterfield.

Speaking with Don French : The Man Behind the French Silk Assembler Tools

Jim Lawless
Originally posted 5-21-2004. In the early days of 8-bit computing, a programmer’s most often-used tool was the assembler. Due to memory constraints, many of the early 8-bit machines could not run a full assembler. At best, one could hope for some sort of machine-language monitor that would include a mini-assembler and a disassembler. That was … until Don French came along and implemented a symbolic assembler on the unexpanded VIC-20.

Ancient Devtools

Jim Lawless
When I first began using microcomputers in the late 1970’s, development tools for 8-bit machines were precious and mysterious commodities. Most of these sorts of tools that looked to be useful were very expensive. My usage of most of these tools was driven by budgetary constraints. The Gateway Drug : BASIC All it really took to pique someone’s interest in microcomputers was to show them a simple program such as:

Flirtin' with Forth

Jim Lawless
I was a senior in high-school in the mid-1980’s when I first encountered a dialect of the Forth programming language. I was quite familiar with BASIC and Z-80 assembly-language and was just beginning to hand-assemble some 6502 code. One of my instructors brought in King Microware Tiny Forth for the Commodore 64 computer in her lab. I was intrigued, at first, and tried to tinker with Forth. The booklet that came with Tiny Forth described the following line of code that I was supposed to enter at the OK prompt: