This selection from ‘Big Doug’ Selway’s trove of documents on the 1950s Elliott 405 mainframe computer takes us right back to the basics. First up is a ‘functional block diagram’ of the system. And what I find interesting about this is: How basic it is. Computers were really quite crude beasts back then. How it was felt you needed to… Read more »
Well the Zolatron 64 homebrew 6502 computer is getting spiffed up in all sorts of ways. So here’s a quick catch-up before the next big challenge. Backplane The original backplane has been working fine. But I decided to upgrade it anyway. The connectors for the boards were a little further apart than they needed to be. And the new backplane… Read more »
There’s something about this brochure that just screams 1950s. The graphics on the cover, for instance, are straight out of Mad Men. ‘A simplified representation of the National-Elliott Electronics Data Processing System’ is the kind of brochure you wouldn’t think was necessary – or appropriate – for this kind of machine. The Elliott 405 wasn’t something you bought on a… Read more »
Sorry about the headline. When I get excited, my German heritage sneaks out. But godammit, it’s justifed. Okay, so the first attempt at creating PCBs for the Zolatron 64 6502-based homebrew computer was not an unalloyed success. I never got as far as testing the backplane, serial board and VIA board because of a monumental screw-up on the main processor… Read more »
History isn’t just about dates and the events that get memorialised in statues. Far more fascinating is the personal and the quotidian. A thumbprint left in an ordinary ceramic bowl is a more direct connection to the lived experiences of people the past than any number of crowns and sceptres. And I think there’s an aspect of even recent history… Read more »
Here’s something I’ve only just learned about the BBC Micro: you can burn ROM chips using modern EEPROMs. Who knew?* One of the strengths of the BBC Micro was the way it handled ‘language’ ROMs. The quotes are there because while many of these ROMs were, indeed, programming languages, others were applications such as word processors, spreadsheets, utilities and so… Read more »
No, this is not a post about stalking. I’ve been toying with a design for a simple 6502-based homebrew computer for a while now. I’ve built a kit and am in the middle of laying out the schematic for the first board for my own design. So I was thrilled when Ben Eater, one of the best educators on YouTube,… Read more »
I’m easily pleased. Leave me alone with a breadboard, multimeter, oscilloscope and a previously unencountered IC, and I can amuse myself for hours. Well, minutes anyway. It’s fun to fire up a chip and watch it do its stuff. And even more fun if it’s an old chip. But before we get to the IC itself, let’s fill in some… Read more »
My recent PC build was undertaken partly to allow me to play Elite: Dangerous. There was no small amount of nostalgia involved in that decision: the original Elite was one of the few games I played back in the 8-bit days. But while I can now play the two incarnations of the game – separated by 30-odd years – side-by-side, there… Read more »
Nostalgia ain’t what it used to be – it’s a lot better. Once upon a time, examining the past relied heavily on memory – an unreliable witness at best. Maybe you could dredge up a few old magazines and books, some dusty photos and a few other artefacts. But you were mostly dependent on whatever you’d personally kept from the… Read more »
There are three things that are certain in life – death, taxes and blown capacitors in old electronic equipment. But at least you can do something about the last one. Powering up a 35 year-old computer that has sat in a loft for the past two decades is foolish. But we did it anyway. The BBC Master ran fine for… Read more »
It’s always the same. “I’ll just hack out this quick program,” you think. And you get it to the point where it works and does the job you intended it to do. But then: “Maybe it would be nice if it also did this…” And even when you’ve added all the functionality the program will bear, and your wife is… Read more »
In the last post, I mentioned how I’m using a RetroClinic DataCentre to make it easy to transfer files between the BeebEm emulator on my PC and my real BBC Master 128. A USB memory stick plugged into the DataCentre becomes my main disk drive (*DRIVE 5) for program files. It also holds floppy disk images (single-sided .SSD and double-sided… Read more »
No, this isn’t going to be a tutorial on BBC Basic. Nor am I about to offer programming tips and tricks. This is about being comfortable while hacking. In the last post I wrote about recreating the first serious program I ever wrote on the BBC Micro. And I mentioned that I’d written the code using the BeebEm emulator running on… Read more »
So what was your first program? You know, the first one that meant anything. My guess is that when you unwrapped your first home computer (mine was a Sinclair Spectrum 48K) the lines of code you typed were little more than snippets – changing some colours on the display, perhaps, or making rude words scroll endlessly down the screen. You… Read more »