This is a short blog post to reference the slides from my builderscon 2016 presentation. I had a great time at buildercon, the talks were varied and engaging from a wide selection of Japanese makers. I’m grateful to the builderscon organisers for accepting my talk and inviting me to present at the inaugural builderscon conference in […]
#arduino
8 posts
3 Dec 2016
31 Dec 2014
This project was featured on Hackaday and the Atmel blog. For the next step in my Apple 1 replica project I decided I wanted to replace the Arduino Mega board with a bare Atmega MPU with the goal of producing a two chip solution — just the Atmel and the 6502, no glue logic or external support […]
26 Dec 2014
Woot! This project was featured on Hackaday. No Apple 1 under the tree on Christmas Day ? Never mind, with a 6502 and an Arduino Mega 2560 you can make your own. The Apple 1 was essentially a 6502 computer with 4k of RAM and 256 bytes of ROM. The inclusion of a 6821 PIA and a […]
7 May 2014
I have several projects on the hop at the moment which require control over a serial port, actually a serial port emulated over USB. So for the last few days I’ve let myself be distracted by writing yet another serial package for Go. github.com/pkg/term term is built on a lower level package, called termios which provides […]
16 Feb 2014
Mea culpa In my first post I said that I believed the simulator performance was 10x slower than a real PDP-11/40, sadly it looks like that estimate was well off by at least another factor of 10. Yup, 100x slower than the machine I tried to simulate. At least. More accurate profiling After my last […]
25 Jan 2014
In my previous post I had figured out that I could capture memory accesses in my simulator and send them elsewhere. In version 1 of the design I (ab)used the onboard mini SD card to simulate the entire address space. This was a very 1950’s solution and came with matching performance. Still, it did give […]
24 Jan 2014
18 bits of core memory In Schmidt’s original javascript simulator, and my port to Go, the 128 kilowords (256 kilobytes) of memory connected to the PDP-11 is modeled using an array. This is a very common technique as most simulators execute on machines that have many more resources than the machines they impersonate. However, when I […]
23 Jan 2014
Introduction It all started with Javascript. In April of 2011 Julius Schmidt wrote a PDP-11 emulator that ran in a browser. I thought that this was one of the most amazing thing I had ever seen. Late last year I ran across the link again in my Pocket backlog and spent a little time poking […]