AltairClone wrote:Let me make sure I understand your setups correctly.
1) If you connect the TTY to a dumb terminal, what you type on the terminal keyboard prints properly on the TTY and what you type on the TTY shows up properly on the terminal screen.
CORRECT
AltairClone wrote:2) In your second configuration, you have the TTY connected to the 2nd serial port on the Altair Clone and run the "SERBUF 2" command under CP/M. On the CP/M operator console, what you type properly prints on the TTY, but when you type on the TTY, the wrong character displays on the operator console. However, the same wrong character displays each time a given character is typed on the TTY.
CORRECT
AltairClone wrote:In configuration #2, what is the operator console - a terminal emulator or the same dumb terminal from configuration #1? If the operator console is not the dumb terminal, what happens if the dumb terminal is used as the CP/M console?
I first had minicom terminal emulator as operator console. I tried your suggestion and used the dumb terminal as the operator console. The behavior is essentially the same, I get the same wrong character when I type on the TTY. However, the characters displayed by minicom and the dumb terminal are different. (For a given TTY keypress I get the same wrong character each time in minicom and using the dumb terminal the behavior is the same but the actual character is different)
I found online there are at least two (more?) different extended ASCII character sets, which seems to explain why minicom and dumb terminal display different characters. In other words the same extended ASCII codes can map to different characters so apparently minicom and the dumb terminal implement different extended ASCII character sets.
AltairClone wrote:In configuration #2, give several examples of the character typed versus the character displayed.
I get extended ASCII characters on both minicom and dumb terminal. Here are the code numbers as best I can tell (I couldn't always match the code with the same character from different character sets so it's my assumption this is the code being used to display the character):
E = 197
O = 207
A = 193
I = 201
U = 213
R = 210
Y = 217