> From: Brent Hilpert >> The trimpot on the board says to me that the clock is most likely a >> simple RC affair.
> There's a 7493 (4-bit counter) on the board as well, which looks to > have connections to the dip switches beside it, in all likelihood the > baud rate divider and rate selection Yes; but the trim pot is also there because one has to set the basic clock to one of two values, depending on whether one wants the 150/.../2400 selections, or the 110/etc selections; one has to set it to 26 usec for the former, and 35.5 usec for the latter. So drift would have been an issue, but not initial component values... Noel