After getting the FPGA test rig up and running, the next stage was to attach it to the 6809 SBC. This was critical if I am to incorporate one into the core of my next computer. To start with I utilised the 7 segment displays as an output latch. Since I had 16 bits of display (four seven segments) I… Read more »
In the end I ordered some additional PLCC sockets from the UK and was surprised and happy that they arrived in only a couple of days. Soldering the sockets was easy, considering the board lacks a solder mask. Possibly the use of some liquid flux helped. I was happy with the result although it is not quite perfect: The next… Read more »
When working with solderless breadboard, one of the concerns is how to power it. Ideally I would have a nice bench PSU but, being cheap, I makedo without one. In the past I have stumbled around with various solutions, including using the power pins on a USB serial breakout board, using an AVR programmer header just for the purpose of… Read more »
This blog post is a bit unusual because all I’m able to write about are problems. In short I made up my FLEX6000 dev board but could not get it to function. Here it is in all of its glory: As you can see, I didn’t bother to fully populate it. The route cause of the problem, I suspect, is… Read more »
This last few months has been a bit “scrappy” on the projects front. I’ve not made as much progress as I’d hoped but have started down several different fronts and have done a fair amount of reading. To learn about implementing a DMA controller, I initially started working on a new 6809 computer core on breadboard. In the end I… Read more »
My little micro is coming along very nicely. One thing has been lacking for a long time now though: a way to control and use the computer without using the serial console port. In summary a keyboard is required. There are a couple of approaches to interfacing what is essentially a switch matrix with a microprocessor. The two main ones… Read more »
I haven’t written in this journal in two months now. I’ve been busy with work, looking after my son, etc. But I have, in the past few months, squeezed in the odd hour here and there on my projects. I’ve managed to get quite a lot done, and haven’t really felt like updating this blog until now. This entry may… Read more »
I have, for about a month now on and off, been working on the controller board for the toner-transferring laminator. This involved buying some new tools including a drill press add-on for my Dremel multi-purpose tool, a chuck for the Dremel, and a collection of drill bits in various sizes. First of all, here is a picture of the finished… Read more »
Last Monday, April 28, the PCBs arrived. They only took a little over 72 hours door to door from Hong Kong. Pretty amazing service from DHL. And amazing service from Botech, who have done an excellent job making up my design. Here’s a picture of the five boards in their little wallet: And here are pics of the bottom of… Read more »
This last month or so I have been working on two fronts: finalising the circuit for the computer, and working on my home made PCB fascilities. So, the circuit is finished. For power the board has two options: USB, like the previous design, and a Molex harddisk power connector. Because of the high current sourcing with a PC power supply… Read more »