Sunday, February 19, 2017

Lee Hart's Z80 Membership Card

I bought Lee's Z80 Membership Card as a kit more than a year ago but only just got around to building it.

Instead of trying to build it to fit in an Altoids can as originally designed by Lee, I decided to make the build a little bit more versatile for future expansion and used Arduino-style connectors to enable stacking additional cards below the CPU board.

It's a good thing I did as Lee is working on a Serial/RAM/SD-card board that will allow this little gem to run CP/M!

Along the way, I also discovered the joys of FTDI USB-Serial mini-boards. Yay! No more RS232 voltage converters! And painless serial console from my Mac.

My other touches of "customizations" include IC sockets for the TTL chips and a barrel socket for an external 5V power supply for when the FTDI is not being used. When the FTDI board is used, a short across pins 19 and 20 of J2 connects VIN to VCC, thus powering the whole setup from the USB port of the Mac.

Thursday, February 9, 2017

kswichit's 8080 Microprocessor kit

Ordered through Ebay. It took forever (>1 month) to get delivered thanks to US customs.

The 7805 voltage regulator did not have a heatsink: bad design. Fixed.