Current Status: Concept only, untested
Date: 19th July 2002
License: Creative Commons Attribution 3.0 Unported License
Probably a first, a complete but untested, design for the A1200 clock port.
Schematics, design notes and some timing diagrams included.
Why do this?
I have authored a technical note on Aminet on the clock port and received a few emails asking how to design a card for the clock port. The best way to answer the emails would have been to send a design, which I did not have. So I set about designing a serial port card to learn more. This is the result.
What about software?
This is the biggest problem. A driver would need to be written. It may work with other clock port serial cards as they are of similar design but I have not tried this.
What are the specifications?
- Uses a PC16550D UART, the original from National Semiconductor that is used in most PCs, capable of 1.5MBaud, limited to 250KBaud in this design.
- The UART has a 16 byte FIFO to reduce CPU overhead.
- 250 KBPS max data rate.
- Only requires 3 ICs.
Here are the design notes, which explain how the card was designed and some of the design decisions.
The Schematics are below:
You can download everything here.
By Ian Stedman, 19th July 2002