Author Archives: aslak

Keyboard finished and PCM sound output prototyping

The bring-up of the keyboard controller board was a protracted affair. The first problem was obtaining an RJ10 cable. When drawing up the schematics for the IO board and the keyboard controller board I had naively assumed that the RJ10 cable I had salvaged from an old telephone was wired straight through with pin 1 connected to pin 1 etc…. Read more »

Keyboard controller construction and a DRAM controller

Receiving deliveries of brand new electronic components is exciting! The order from Mouser included a part for the keyboard controller board and multiple parts for MAXI000. On the same day I also received the previously described PCBs from allpcb.com. Here’s the front of a keyboard controller board: As usual they look great. A quick test of the updated RJ10 socket… Read more »

A mini-review of a microscope, a keyboard controller, and a SIMM adapter

When building PCBs with small Surface Mount components, it helps to be able to view the board with some magnification. This is useful for both the actual placing and soldering of components, and for inspection of the board after the fact. With the practice boards I made up previously I did have a look at them, after the soldering, with… Read more »

The switch back to Linux

      No Comments on The switch back to Linux

I’ve previously written about my dissatisfaction with modern Apple Macs after being a big fan of them for more then a decade. In summary, the machines are over priced, have had the useful ports removed, and further, the OS appears to no longer be improving in any meaningful way. I’ve not been using a Mac laptop since my 2013 Macbook… Read more »

Adventures with Surface Mount construction

      No Comments on Adventures with Surface Mount construction

I’ve been putting off learning how to build PCBs with Surface Mount Devices for many years. For the most part, I’ve had very little reason to look into SMD/SMT. Most, but not all, of my electronics projects involves the use of 80s and 90s parts which are usually available in through-hole packages; indeed many are only available in through-hole. But… Read more »

VGA improvements

      No Comments on VGA improvements

After trying to make some small improvements to my VGA implementation I’ve come to the conclusion that it is deeply flawed. Whilst I can produce a working video controller that appears to operate reliably, if I make an even insignificant change to the VHDL code then corruption when doing writes into the video memory usually occurs. It’s also clear, from… Read more »

Thoughts on the MAXI000 and other things

      No Comments on Thoughts on the MAXI000 and other things

Before getting to the MAXI000, a brief discussion on some unrelated things. First up, I’ve finally bought an oscilloscope, specifically a Rigol  DS1054Z. This is a fairly low end 50Mhz DSO (Digital Storage Oscilloscope), which should nonetheless be perfectly adequate for my needs for the foreseeable future. One nice feature: it has four inputs. I must admit that a lot… Read more »

IO board bring up

      No Comments on IO board bring up

The IO boards arrived about a week after putting the order in. The front of one of the boards: And the back: Interestingly I received two extra boards. An extra usable board and another one. The other board had been used for some kind of testing by the manufacturer as it had a piece cut out of it. The box… Read more »

Progress on the VGA, Keyboard, Sound and IDE board

      No Comments on Progress on the VGA, Keyboard, Sound and IDE board

The IO board for the MINI000, outlined in the last post, has been designed and the PCB, pending some final checks, will soon be ordered from the allpcb.com PCB house in China. A few ICs have not made it. I’d hoped to include a MC68230 (PDF) but as they are available only in DIP48, there’s just not enough room for… Read more »

Thoughts on future projects (68K!)

      No Comments on Thoughts on future projects (68K!)

This blog post does not document what I’ve done in my hobbies, except for some small projects, but rather what I plan to work on next. Before getting to that though, I should finish my description of the progress I’ve made with the VGA controller. I have attached the  EPF10K10 (PDF) FPGA to the 68000 CPU bus, and have had… Read more »