Is Collapse OS really a practical proposition?

Is it really possible to design an operating system for a computer built from scavenged parts after civilization has failed?

Categories: retrocomputing, Z80

Running CP/M on the Raspberry Pi Pico microcontroller

This article introduces CPICOM -- an emulator for CP/M 2.2 on the Raspberry Pi microcontroller.

Categories: retrocomputing, Pico, C, Z80

Getting back into C programming for CP/M

This article is about how programming for CP/M, usng a 40-year-old C compiler, differs from modern C development, even for console applications.

Categories: retrocomputing, C, Z80

Getting back into C programming for CP/M -- part 2

Using the 1989 HI-TECH C compiler on CP/M, and some general observations about CP/M programming with real hardware.

Categories: retrocomputing, C, Z80

The vexed problem of generating delays in a CP/M program

CP/M has no timing or delay functions, because CP/M never stipulated that compatible hardware have any kind of clock. So how do we implement short (fractions of a second) delays in a CP/M program?

Categories: retrocomputing, Z80

CP/M resources

A landing page for my various CP/M articles and utilities.

Categories: Z80, retrocomputing

CP/M forty years on -- what it was, and why it still matters

Why was the CP/M operating system so successful? Forty years on, why should we care?

Categories: retrocomputing, Z80

Serial device mapping in CP/M

CP/M only recognized four serial devices. How did application cope when more than four serial ports were installed?

Categories: retrocomputing, Z80

Playing Zork 1 on a CP/M emulator on Linux

In the last few years there has been a revival of interest in 8-bit microcomputers from the 70s and 80s. Many of these were based on the Zilog Z80, and many ran CP/M. This article about getting started with CP/M using an emulator on Linux.

Categories: general computing, retrocomputing, Z80

cwordle -- A Wordle-like word-guessing game for CP/M

Building a CP/M implementation of the notorious Wordle game.

Categories: retrocomputing, C, Z80

Developing KCalc-CPM -- a scientific calculator utility for CP/M

My first CP/M program for nearly 40 years -- how, and why, I wrote it.

Categories: retrocomputing, C, Z80

Using a CP/M machine to log into a Linux server using an RS232 connection

Because -- why not?

Categories: retrocomputing, Z80

Writing new interactive fiction games for CP/M using PunyInform and Linux

It's still possible to write text adventure games for CP/M and other small, vintage computers. Here is one approach, using Linux as the development platform.

Categories: retrocomputing, Z80

Adding a floppy disk controller to my RC2014 Z80 system

No 80s computer is complete without the chucka-chucka-chucka sound of a floppy disk drive doing its thing.

Categories: electronics, Z80, retrocomputing

Designing a dual 5V-to-RS232 serial level converter for the RC2014

Using an RC2014-based retrocomputer with genuine RS232 peripherals requires support for voltage level conversion. Although converter modules are inexpensive and widely available, I wanted to design something that would plug into an RC2014 backplane, just for neatness.

Categories: electronics, Z80, retrocomputing

Some thoughts on a DS1302 real-time clock board for RC2014/Z80 and CP/M

Constructing and programming a real-time clock board for my Z80 CP/M system

Categories: C, electronics, Z80, retrocomputing

Constructing and programming a YM2149 sound board my RC2014 Z80 system

An 80's-style 8-bit computer has to be cable of making 80's 8-bit sound. In this article I describe adding a sound board to my RC2014 system.

Categories: electronics, Z80, retrocomputing

Adventures with RC2014, Z80, and CP/M

This is a landing page for my various articles on building a period-appropriate CP/M system using the RC2014 bus.

Categories: Z80, retrocomputing

Exchanging files between an SC130 CP/M board and a Linux system

This article describes a couple of methods for sharing data and code between a CP/M system with RomWBW BIOS and a Linux system.

Categories: C, electronics, Z80, retrocomputing

Updating, building, and flashing RomWBW on an SC130 CP/M system

A step-by-step guide to building and installing a modified version of the RomWBW firmware on a CP/M Z80 board.

Categories: Z80, retrocomputing

Multi-source Z80 assembly programming for CP/M

How to use Microsoft's Macro80 and Link80 utilities on CP/M, to build a program consisting of multiple assembly-language files.

Categories: retrocomputing, Z80, assembly

A self-contained CP/M computer based on the Z80 Playground

This article describes how to create a self-contained CP/M-based microcomputer using a Z80 single-board computer, a Raspberry Pi Zero, and some assorted electrical parts.

Categories: Z80, retrocomputing