identifying terminal by escape codes?

[Jonno Downes]

I just took a look at the 4010 manual, and realised that US (0x1F)
selects 'alpha mode' and GS (0x1D) selects graphics mode.

The very first char output by the prom is US, followed by CR/LF  then
'?' - it would make sense that the monitor sets alpha mode first.

this sequence also looks like it is using graph mode to position the
cursor, then flicks and to alpha mode to print a char, back to
graphics to move cursor back to where it was, and (over)prints a
different char. I haven't yet worked out whether 0x12 and 0x14 in
alpha mode displays a custom graphic, but might be some kind of
flashing cursor

1D		  Group Separator		
37		  7					
7F		  DEL				
20		  SPACE
40		  @					
1F		  Unit Separator		
12		  DC2				
1D		  Group Separator
37		  7
7F		  DEL
20		  SPACE
40		  @
1F		  Unit Separator
14		  DC4

not sure what these are though:

1F 26 24 <x y z> : ESC & $ <xyz>
1F 26 27 <x y z> : ESC & ' <xyz>
1F 26 21 <x y z> : ESC & ! <xyz>