An old saying, credited to Paul Erdős, is that “a mathematician is a machine that turns coffee into theorems.” Although I have heard other people being credited with it as well. One of the well-known versions of this is that “Computer Scientists turn coffee into urine” – obviously someone who thought that computer scientists doe not meet the high standards on mathematicians. Last night at the Adelaide Hackerspace meetup we got a new version of this:
“An Engineer is a machine to turn time into computers”
One of the fellows there – unfortunately I did not catch his name – has had a period of unemployment so, rather than head off to the beach or hide in his bedroom suffering from self-pity, he invested the time he had in hand soldering a complete Z-80 based computer. WOWZAH!
The happy maker and his wonderful handsoldered creation.
As I understood it, he has built an IDE interface to use a normal PC hard drive. Because the Z80 is an 8 bit machine and the IDE standard is 16 bit, there was a bit of high-byte / low-byte wrangling to be done. The current screen arrangement is via a serial port, which sounds remarkably low-tech until you remember that serial terminals are rare, so the easiest thing to do is to use an old laptop as a terminal: which means that the terminal is several times more powerful than the machine itself! There was some discussion about building a small (possibly Arduino based) interface for using a TV screen as the terminal, which would be totally retro and quite fantastic.
I am not sure now visible it is in the photo (I see it because I know it is there) but every connection has been hand soldered and the board is Veroboard / stripboard with the traces cut with a knife. This is a level of exactness and detail that, I must admit, I find daunting and amazing to the extreme. Congratulations!
From left to right: CPU, serial interface, IDE interface, plus a lot of logic "glue" to help it all work.
Run CNC 