RTTY uses Baudot code, which has 5 data bits, 1 stop and one start bit. That is what I am hoping to be able to transmit, but I need to somehow convert the RS-232 output of the GPS device to RTTY format. The library I linked to in my previous post supports "ASCII 7 or 8 bit, 1 or 2 stop bits, 50 or 300 baud speeds and has XOR checksums using USB type transmissions.". Is that what you were asking? :\