I’ve been very busy for the last few months, with many different things. This post will therefore be a bit of a mess, unfortunately. I’m at a place where I’ve been before a few times: not knowing the most interesting road to explore, since there are so many, and they are all fascinating and rewarding in their own way. First… Read more »
As mentioned at the bottom of the previous post, I’ve been designing a new 32 bit processor, and this post is concerned with the design of that processor’s Instruction Set Architecture. The objectives for this project are as follows: To learn as much as possible from the experience To leverage what I learned making my previous 16 bit processor To… Read more »
Since the last post I have added functionality necessary to make it possible to use the computer from a directly connected keyboard and screen. This required two things: Making the already written PS/2 controller VHDL implementation available to the Linux kernel by adding a PS/2 driver. Modifying the existing, and somewhat hacky, VGA controller for my video card and writing… Read more »
Whilst I did attach the graphics card to MAXI030 it was only to confirm that I could turn the card’s LED on and off. The VHDL for the Cyclone FPGA is in a sorry state and needs major work before I use it in any kind of meaningful way. Continuing on with MAXI030 my first port of call was to… Read more »
While working on the design for MAXI030 I completed another project: a new workbench microscope. After watching various videos on the topic, I came to the conclusion that a setup with just a camera and large TFT screen would be best for me, ie. one without eye pieces. I have various things wrong with my eyes, including poor stereoscopic vision,… Read more »
Though the 68020 based MIDI020 computer is a workable design, it suffers from a few problems: The main one is the board is not 100% reliable. Very occasionally it will fail to start. I’ve tried to diagnose this problem but without success I can only run the processor at half the rated speed, 12.5MHz if the SIMM slot is used… Read more »
Three PCBs arrived promptly from JLCPCB: The version 2 Test+SRAM board The version 2 Ethernet+Printer+Joystick board The version 1 Video+Sound board The version 1 of the top two boards are described at the bottom of the post about the MIDI020 68020 computer, if you haven’t read it. The first job was to build up the version 2 Test+SRAM board. Whereupon… Read more »
For the last few weeks I’ve been working on the design of a video card for my 68020 based computer, MIDI020. Though it will principally be a video card, it makes sense to include sound generation functionality as well, and I’ve been looking at a couple of approaches to this. Though I could look at using an FM synthesis IC,… Read more »
The build of MIDI020 is nearly finished. There’s been some hickups along the way, but I have managed to overcome them. My order to jlcpcb.com consisted of three boards: The MIDI020 main board The Test+SRAM expansion card The Ethernet+Printer+Joystick expansion card To make things interesting, and because I wanted to try them out, each came with a solder paste stencil…. Read more »
I2C, I²C or Inter Integrated Circuit is a synchronous serial protocol designed by Philips in the early 1980s for linking together ICs on PCBs so that they can exchange data. It operates in the same area as SPI, which I’ve talked about in this blog a few times. I’ve also talked about I2C before though not for a long time…. Read more »