Tephra Blog

Tephra Blog

PDP-11 Timing Repair

PDP-11 Timing Repair

The next part of my PDP-11 to fix is the M7234 - Timing card. It's responsible for the system clock and unibus bus operations. In this situation, the issue presented itself as a fault related bus operations. Symptoms Console Any operations involving the unibus did not work. Examine,

PDP-11 uWord Repair

PDP-11 uWord Repair

In December of 2024, my PDP-11 developed a new fault in the uWord board. The system had gone from mostly functional to almost completely dead!

PDP-11/40 Servicing

PDP-11/40 Servicing

On this page, I have documented all the things I have repaired on my PDP-11 and things to watch out for with your PDP-11 Power Supply Modules The first time I powered up the PDP-11 a full full bridge rectifier failed in one of the power supply modules. I have

TV Composite Mods

TV Composite Mods

A very crude guide for modding old TVs to accept composite video inputs. Also a list of chip and how to mod them.

PDP-11/40 Test Programmes

PDP-11/40 Test Programmes

Here is a list of small test programs to run on the PDP-11/40 to verify its basic functions.

MicroVMS 4.7 Installation on a MicroVAX II

MicroVMS 4.7 Installation on a MicroVAX II

This is a rough guide on installing VMS 4.7 into a MicroVAX II running an MFM Emulator and GoTek floppy Emulator. Required Equipment * MicroVAX II * OpenSIMH v4.1 Simulator (Pre-built Simulator) * GoTek Emulator * MFM Emulator * VMS 4.6 and VMS 4.7 * MicroVAX-II Diagnostics (MDM) (Source) Overview Installing VMS

IBM XT MFM Emulator

IBM XT MFM Emulator

Emulating an MFM drive using David Gesswein's MFM Emulator and installing MS-DOS 3.30. Required Equipment * IBM XT * MFM Controller Card * MFM Emulator * GoTek with FlashFloppy * DOS 3.30 Installation Images (download link) * Appropriate MFM and Floppy Ribbon Cables MFM Cables Both cables have identical construction, and both

Z80 Single-board Computer

Z80 Single-board Computer

A single board Z80 computer of my own design. 32K ROM, 64K RAM running at 4Mhz.

Adding Static Files To Ghost

Adding Static Files To Ghost

Adding static files to Ghost with Nginx. To allow clean and simple embedding of scripts and tweaks.

Convergent Technologies AWS

Convergent Technologies AWS

Some time ago I found on facebook marketplace a box of scrap electronic boards. In that box there were the remnants of at least two systems. A Honeywell Bull XPS-100 and the CPU board of a Convergent Technologies AWS.

Adding Comments To Ghost

Adding Comments To Ghost

Something I immediately noticed was Ghost’s lack of a comment system, which for me was a must have feature. So I started looking around for a solution and I am happy to say that I found one. Comment widgets Well first let's get an understanding of how

Hello world

First ever blog post! Deploying Ghost with Docker Compose