B9, I was working on a RTTY decoder, and I was using the BASIC program " RTTY.BA (https://ftp.whtech.com/club100/tel/rtty.ba)" and "RTTY.DO ( https://ftp.whtech.com/club100/tel/rtty.do)" as a guide. This program will receive a serial data string on the RS232 port from the "Terminal Unit" (which converts two alternating audio tones to digital "1" and "0" levels. It can also send data to the "Terminal Unit" to change the digital "1" and "0" levels to the same two audio tones.
I wanted to make a program only for receive. I was using the "RTTY" program to understand how the PIO timer, which is used for the UART baud clock, was set to make the UART work at the odd speeds that were used "in the old days" by the BAUDOT encoded teletypes. John, The "Inside the Model 100" book by Carl Oppedahl does not list FF8Dh. The last address noted is FF8B which is noted as "address of baud rate". I have seen the notation in the "Covington ROM Map", and I believe this is where Ken got the same notation in his ROM listing (in his personal library on the Club100 page). But it doesn't seem that Robert Covington ever wrote a book on the Model 100. For such a detailed ROM listing, I would have expected that he would have. He must have been involved in accessories for the Model 100 in some capacity. Regards, PeterN
