blog.jmp.no

Electronics, coding and hacking. And ADD.

The ATPuter

2011
19
September

Here's another oddity I never really wrote anything about. This didn't catch on to me. Don't get me wrong, but it was a "too easy" approach towards building my own computer. I'll explain why.

ATPuter

What you're looking at here, is an ATmega128 based computer. Since I'm a fan of reusing components (and I'm a frequent breadboarder) the SMD ATmega128 is on a 64-pin SMD-to-DIP adapter. VGA signal and a PS/2 keyboard input functionality was driven by the MicroVGA interface by SeCons. I wrote a custom BASIC implementation, so switching it on would give an instant 8-bit retro experience. The wires on the board are for JTAG and power.

Kind of cool, but, you know. Connecting the dots is not really a challenge. Most of the work was writing the software, and I have enough software projects.

Another project forwarded to the dust collector ensemble!


The decoder

2011
19
September

This was a simple project I finished a while ago, but never wrote anything about.

The lack of this device was discovered while debugging my 6502 computer (which I will cover later). I needed to debug the address bus while stepping through a simple program in ROM. Due to the lack of a advanced oscilloscope, I wanted a solid device I could hook up to anything with a 16 bits wide bus or less.

16-bit address decoder

This is the final layout. The address bus is segmented in 4 bits, each passing through a MC14495, which happens to be a CMOS 4-bit parallel to 7-segment driver. All I did was to connect the dots and add a few rails for the power, and etch the bugger.

Yes, it is a simple device, but it has proved to be extremely functional and useful.


New blog; renewed courage.

2011
19
September

Welcome to my new blog, where I'll be discussing my projects, ideas and thoughts on my personal electronic projects, favorite micro controllers and C programming.

This blog will mainly be written in English, to welcome the international audience which appears to be growing.

I'll try to keep my usual lines, with explaining and de-mystifiing my recent finds, as I explore my way through the immense jungle of transistors, opto-isolators and logic gates.

Wish me luck.


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