The Covington map is from the CompuServe SIG archive. I assume he was just a guy that disassembled/reverse engineered the ROM. It was a common thing for hobbyists to do when they got a new microcomputer.
-- John. On Wed, May 6, 2026, 1:05 AM Peter Noeth <[email protected]> wrote: > 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 > >
