RCRTSTRAPSGH for Handshaking
The G and H straps of the HP terminal control datacomm handshaking. If you pull up your Terminal Config screen, it should look something like this:
InhHndShk(G) YES Inh DC2(H) YES
Since these are "inhibit" straps, YES actually means "no, don't do the handshake." G and H control whether the terminal waits for a DC1 and/or DC2 prompt character from the computer before sending input (such as on terminal status requests, or upon pressing Enter in block-mode). If the straps are configured incorrectly, the symptom is a hung terminal (i.e., the terminal is waiting for a prompt that is never going to come, or the terminal sent the data before the computer was ready because it didn't wait for the prompt).
To override the G and H strap settings of your CRT, use the RCRTSTRAPSGH variable. The default value for Qedit/UX is 3, which means no handshake (G=YES, H=YES, inhibit both). A value of 0 means use handshaking and may be necessary if you "shl" to an MPE system and use terminal-based typeahead. Unfortunately, a 0 value makes function keys lock up in Line mode Qedit/UX.
The valid values for the RTSTRAPSGH variable are as follows:
Value | G | H | comment |
0 | no | no | (handshaking active) |
1 | no | yes | |
2 | yes | no | |
3 | yes | yes | (default for HP-UX) |