A parallel port and a demonstration of the Z80 computer Sunday, 5th September 2010

The last piece of hardware to add to the computer was a parallel port. These have eight data lines and nine assorted control and status lines. My last two 8-bit I/O expanders provide sixteen of these seventeen lines, and the final one was provided by the DS1307 real-time clock chip which happily has a spare pin on it that can be used as an output. This parallel port can be used to print from the computer. Some software has printing capabilities built in (such as the text editor VEDIT Plus), but by pressing Ctrl+P in CP/M any text sent to the display will be simultaneously sent to the printer.

Comments CP/M Parallel port Printing Z80 Z80 computer