This is the first time I have heard of DECterm supporting more than 24 lines,
so the answers which you provide are particularly helpful since they confirm the
results that have been found by E. Groenenberg and John Wilson, and
specifically in respect of screens of more than 24 lines of which you are the only
one to note what DEC did when more than 24 lines are available.
For another data point, I dug out my VT510 and set it to 48 lines per page.
The results were the same. The scrolling region was not altered if the second
parameter was larger than 48. In light of what John said in another posting,
I also tried defaulting the second parameter and setting it to zero. In both
cases, the scrolling region was set to start at the line specified by the
first parameter and end at the bottom of the screen. This also worked for me
on a DECterm.
Finally, I tried a Qume QVT202 (80x24 only) which behaved the same.
Regards,
Peter Coghlan.