God <root%bostonu.csnet@csnet-relay.arpa> (11/08/84)
I concur. I built a real-time portable pulmonary testing lab running on an LSI-11/2 off of only RX02s (with swapping etc). One person would be filling in questionairres while another would be getting a lung test (A/D, ~20KHZ, 14bit.) It worked fine, an occasional hesitation for a few seconds (but with an RX02 as a swap device whoddyaexpect? It was MINI-UNIX/V6. Just requires a smart driver, not terribly unlike one of the psuedo-dma pollers for a DZ11. UNIX being 'bad for real time' is a myth perpetrated by vendors who sell O/S's that are bad for anything else. An even better idea is to go get a rusty old apple or some such, add an A/D board, floppy and parallel board to hook it up to the unix system and use it as an intelligent, programmable A/D device with a 64KB buffer. -Barry Shein Boston University
afn@masscomp.UUCP (Al Nugent) (11/12/84)
> > I concur. I built a real-time portable pulmonary testing lab > running on an LSI-11/2 off of only RX02s (with swapping etc). > One person would be filling in questionairres while another > would be getting a lung test (A/D, ~20KHZ, 14bit.) It worked > fine, an occasional hesitation for a few seconds (but with an > RX02 as a swap device whoddyaexpect? > It was MINI-UNIX/V6. Just requires a smart driver, not terribly > unlike one of the psuedo-dma pollers for a DZ11. > UNIX being 'bad for real time' is a myth perpetrated by vendors > who sell O/S's that are bad for anything else. > > An even better idea is to go get a rusty old apple or some such, > add an A/D board, floppy and parallel board to hook it up to > the unix system and use it as an intelligent, programmable > A/D device with a 64KB buffer. > > -Barry Shein > Boston University A rusty old apple might do the job but there are quite a number of people who need real-time performance in a UN*X environment. As for when is Unix no longer Unix I cannot say. The Masscomp implementation is true Unix (System V.2 and BSD4.2 plus Real-Time enhancements) and with our Data- Acquisition and Control Processor you can gather data at 1 million 12-bit samples per second. Even our multi-CPU kernel is still "real" C/Unix; (i.e. more than one CPU pathing one copy of the kernel independantly). If an apple will do the job, fine, but when you need REAL unix doing some real-time (or non real-time) work we have the answer. Alan Nugent, Massachusetts Computer Corporation. Westford MA ...!{ihnp4,harpo,decvax}!masscomp!afn (617) 692-6200 x224