CLUB 100 Library - 415/939-1246 BBS, 937-5039 NEWSLETTER, 932-8856 VOICE Document file for RTTY.100, a basic program to allow the M100 to emulate a RTTY terminal at 60 thru 100 WPM. REQUIRES an external TU (terminal unit). Of interest mainly to ham radio operators. Steve Alverson WB8HRV RTTY.100 is a (mostly) BASIC program to allow the RS Model 100 to transmit and receive Baudot 5 level RTTY code. Speeds of 60, 66, 75, and 100 WPM are supported. Both received and transmitted text can be echoed to a printer, and the RTS control line can be used for transmitter control. This program uses the RS-232 port, and requires an external TU (terminal unit) to convert the receiver audio into RS-232 levels, and from RS-232 levels back into tones for transmission. I am using a Flesher Corp. TU-300, but any TU with RS-232 compatible signal levels should work. Note that the TU-300 does NOT support RS-232 xmit control - external circuitry is required. Program Operation: The program begins in receive mode with echo toprinter disabled, at 60 WPM. Function keys F1 thru F4 set the speed to 60, 66, 75, and 100 WPM respectively. F5 toggles in and out of xmit, F6 sets letters mode and starts a new line, F7 toggles the echo to printer mode, and F8 returns to Menu. About thirty characters are buffered in receive mode, and will be transmitted as soon as transmit is selected. If any character is typed which does not exist in Baudot, you get beeped, and nothing is sent. Letters may be typed in upper or lower case - they are converted to upper case before transmissin, but are echoed in lower case (also to the printer, if enabled). This could be useful to differentiate received from transmitted text on a printout. If I understood more about the LABEL line, I would allow the LABEL key to toggle the last line with a description of the function keys. Any takers?? MACHINE LANGUAGE CALLS: Several M/L calls are used in this program. For those interested who do not have access to references, they are listed below. 16969 (4249H) - Turns on cursor 19268 (4B44H) - Print the character in A reg on LCD 27967 (6D3FH) - Print the character in A reg on LST 28210 (6E32H) - Send character in A reg to RS-232 port In addition, a machine language routine is read into array ML. The entry point at ML(0) checks for received characters - if none are present, it returns with X(0) = 0. If a character has been received, X(0)=1, and the character is in X(1). The entry at ML(9) converts the character in the A reg to upper case, and places it in the variable pointed to by HL. This allows transmitted text to be typed in lower case and automatically converted to upper case (Baudot has no lower case). Steve Alverson WB8HRV 75236,341