Monthly Archives: September 2023

Repairing a BBC Master #2: Basic steps

First, do no harm. Second, check the voltages. That’s how the Hippocratic Oath starts when adapted for electronics. If the device under test is not getting the proper power supply, then you can’t reasonably expect it to work. But there’s something I wanted to check, even before I apply power, and this turned out to be a learning opportunity. With… Read more »

Adventures with real-time clocks – part 2

The story so far: I’d been tinkering with an MCP795W20 real-time clock (RTC) chip and having a frustrating time of it. Weird things were happening. It seemed very finicky. I’d put part of the problem down to using a breadboard (still think I’m not entirely wrong about that). It turns out, however, that the biggest problem was my own stupidity…. Read more »

Repairing a BBC Master: #1 – plan of attack

So my poor Acorn BBC Master Turbo is sick … again. And I feel a little bit responsible. Quick recap: the Master developed a problem some years ago. This was ‘fixed’ when a very generous person donated a motherboard from his machine. I never did find the cause of the problem. Since then, however, the machine has spent a lot… Read more »