On 2020-11-18 9:08 PM, Rupert Reynolds wrote:
Attn could interrupt any TSO program
I think ATTN button functionality depends on having an SNA session.
If your TSO terminal is an MVS 3270 I/O device with its own device address, then that is a non-SNA session and so ATTN does not function.? PA1 will perform the TSO attention function - use RESET first to undo an input-inhibited state first if necessary.
Given the limited number of I/O addresses and the growth of networks over the years, as time went on a greater percentage of TSO connectivity came under the SNA and SNA-like umbrella, with ATTN often working even for modern TSO sessions over TCP/IP (depending on the TN3270 parameters used for Communication Server).
When a 3270 terminal is an I/O device, ATTN may not be an AID-generating key - or so I imagine, but I'm not really a network guy.
Cheers,
Greg
