rtty this is a machine language rtty program for the vic 20 that was written by wa9bvs. to run this program at least 8k of expansion memory is required. it will not run on the c- 64 but that machine can be used to copy the program. load the program and enter run. the program will run and go to receive at 60 wpm baudot. the top line shows the status and the next 13 lines show the received text with wrap-around. the type ahead text appears on the lower part of the screen. about 3k of text can be typed ahead while receiving. in receive the vic will respond to the following commands: f1-back to basic f2-110 baud f4-50 baud f5-57 baud f6-45 baud f7-74 baud comm. key + e erases type ahead. comm. key + w erases received text memory. comm. key + a goes to ascii. comm. key + b goes to baudot. comm. key + t goes to transmit. in transmit you type and the word appears on the top part of the screen but the word is not sent until you hit the space bar so you can use delete to backspace and correct a word before sending it. in transmit the following commands are used: comm. key + a sends the type ahead. comm. key + s sends the received text from the memory. f3 (or f4, f5,or f6) send preset messages (cq etc.) comm. key + r goes back to receive. when you go back to receive the letter r appears almost at once in the top line but the program has not finished clearing the buffer until the screen clears. so dont switch off the transmitter until the screen clears. to change the preset messages load the program and enter sys 9385 instead of run. that puts the vic in a special program that replaces the f3 control key buffer with the next 22 characters you type in. delete does not work so be carefull. sys 9412 places the next 11 characters into the f4 memory. sys 9440 places the next 47 characters into the f5 memory. sys 7367 places the next 255 characters into the f6 memory. after changing the memory save the modified program with your new messages. before saving the program you must enter poke 46,38 . after entering poke 46,38 a standard basic save will save the program. to connect the terminal unit (inter- face) to the vic first be sure the terminal unit (interface) has ttl (0 and 5v+) level in and out. then connect pins b and c on the vic user port together with a short wire. (see page 152 of your vic instruction book for a diagram of the user port pins). then connect the center conductor of a shielded cable to pin b of the vic user port and connect the other end of the center conductor to the output of the terminal unit (interface). the ground shield on the cable should be grounded on the vic and the terminal unit. pin a of the vic user port is ground. take a second shielded cable and connect the center conductor to pin m of the vic user port and the other end of the center conductor to the input to the terminal unit (inter- face) . ground the shield of the cable to the vic and to the terminal unit. that is all there is to hook up. have fun !! send wa9bvs a qsl card and let me know how you like the program. make lots of copies for other hams.
Amiga7878