The SymDOS I/O board is custom I/O board for the SYM-1 single board computer that provides SymDOS functionality which allows for floppy disk access using Commodore IEC disk drives. Features

• Commodore IEC floppy disk drive, or SD2IEC, access via SymDOS
• TTY over RS-232 communication via a micro-USB connector
• Cassette audio out (jumper configurable HI or LOW) via a mono 3.5mm jack
• Cassette audio in via a mono 3.5mm jack

TTY over RS-232 communication requires an installed Teensy 4.0 microcontroller. SymDOS functionality requires SYM-1 Monitor version 1.1 (available for purchase separately) and either RAM at $9000 or a burned EPROM addressable at $9000.  I recommend Corsham Tech’s SYM-1/AIM-65 RAM Board. Includes full color manual, a single dupont jumper cable (color may vary) and USB flash drive with SymDOS software and original manual.