TTL to RS232 Adapter

TTL to RS232 adapter utilizing the MAX232 chip.


Summary

This is a 5V TTL Serial to RS232 adapter. It allows a UART like the MC6850 (which runs on 5V logic) to connect to a 12V RS232 port. This is super useful if you have a palmtop computer like the HP 300LX because you can use the palmtop as a serial terminal instead of having to lug a laptop to use as a serial terminal.

Part List

Component Description Origin
DB9 Male Connector RS232 connector. Water damaged TI-99/4A
MAX232 Dual transmitter / dual receiver eBay: "5 oz. ICs for scrap metal recovery"
1uF capacitor (x4) External capacitors for MAX232 Desoldered from PCBs
Front Back

Timeline