arch@ncar.ucar.edu (Arch Mott) (10/06/89)
Greetings! We have a Sun 3/160 running SunOS 4.0.3. In the 3/160 we have what used to be known as an MCP board (Multi-Protocol Comm Processor) and I think is now known as an ALM-2 (?). The MCP board has 1 of its RS-232 ports running bisynchronously with Sun's Sunlink BSC/RJE software. The other RS-232 port is running asynchronously to drive a BDS-1500 line printer. The printer is set to run at 19,200 Baud. I have also tried the printer at 9600 baud. The 2 RS-449 ports are free. The problem is this: When sending data to the printer, the number of interrupts being pro- cessed by the cpu becomes extremely high and system performance degrades to the point of being virtually unusable. Mouse response is horrible, anyone logged in to the system experiences terrible response time and the printer runs at nowhere near it's rated 1500 lines per minute. The board performs satisfactorily when just the BSC/RJE is running. whether or not BSC/RJE is running, the line printer kills the system. Does anyone have experience with this set-up (MCP-->Async Printer) ??? Please help if you can. Send your e-mail to: arch@seri.seri.gov Thanks in advance, Arch.
sturgess@uunet.uu.net (Chris Sturgess) (10/11/89)
Our system (3/180 and ALM-1) suffers abysmal async performance when running a small number of users on screen-oriented programs. So far we haven't found a solution, so I would really appreciate it if you would pass along any answers you get. - Chris Sturgess
sturgess@uunet.uu.net (10/12/89)
I would like to expand on the last question. Our system is also getting killed by async output. We run a 3/180 with an ALM-1 (16 line MUX) and a small number of users on screen-oriented programs. Serial interrupts appear to be the culprit. We are working on the programs to optimize their output, but that is clearly not enough. My question is: does the ALM-2 offer any improvement or are there any third party devices that can offload the CPU a little better?