Memory Input/Output Board Schematics

These are the schematics I used during construction of the Memory Input/Output board. They are simple scans of hand-drawn diagrams. The originals are pencil on notebook paper, and may be a little hard to read in places, especially if I erased something and drew it again. I may replace these with proper graphics drawings, but for now this is all I have.

The original layout diagram is for the board prior to building the byte switcher and serial port. The byte switcher IC's were put on the lower edge of the board as can be seen in the photograph. The serial port IC's are on the right, and the layout is shown in a separate drawing.

Connector Pin Assignments
Data Buffers
Address and Control Line Buffers
Address Decoding 1
Address Decoding 2
Signal Combining Logic 1
Signal Combining Logic 2
Simple Input and Output Ports
Layout, top
Layout, bottom
Byte Switcher
Serial Port Layout, top
Serial Port Layout, bottom
Serial Port Extra Bits and Logic
Serial Port Frequency Dividers
Serial Port Receiver and Driver

© Donn Stewart 2004