computer science

My First Z80 Program

Bruce Ediger

I wrote a Z80 assembly program for my RC2014 Zed computer. I wanted to get a complete CP/M experience, so I used the CP/M 2.2 ASM assembler, LOAD relocator, and the DDT debugger.

I did cheat a little. Although I used the vintage RED editor for some text input, I also wrote some on my Linux laptop, and transferred to the RC2014 Zed via XMODEM.

A Golang Enabled Pattern

Bruce Ediger

The Go programming language has a unique, built-in concurrency model that can make some processing much easier.

Have one goroutine do some (probably recursive) work. It puts results on a channel. The main goroutine reads results from the channel and possibly does some filtering on those results, like output unique values.

CP/M and VAX/VMS Memory Layout

Bruce Ediger

It’s often said that DEC operating systems influenced the design of the CP/M microcomputer OS. Let’s examine that assertion by looking at how a process was laid out in memory.