This is real-time-applications-on-040-cube in view mode; [Up]
Date: Sun 27-Mar-1991 08:23:05 From: houghton@iuvax.cs.indiana.edu (Ric Houghton) Subject: real-time applications on 040 cube We are thinking of purchasing a color NeXT station for research purposes (040 cube, with 40 megs of ram, and a 600 meg harddisk). The only problem is that the required task is timing sensitive. That is, we need to be able to reliably present a visual stimuli at some time x, after another stimuli, auditory (or maybe another visual stimuli) has been started. (Where x is measured in milleseconds.) Does anyone have a feel for how accurate or reliably we might be able to do this task? +/- 1 millesecond is acceptable, but more than that, and we have to start thinking about PC's or Macs. (YUCK!) Intuitively, it seems almost impossible to assure the experimenter that the task will be carried out reliably, but I've not worked with MACH, so I have no clue on this one. Thanks for what ever input, I'll summarize, of course.... Ric Houghton houghton@cs.indiana.edu btw, Any chance there exists a real-time unix for the NeXT? Probably not?.....
Date: Sun 28-Mar-1991 03:22:34 From: DWN2@psuvm.psu.edu Subject: Re: real-time applications on 040 cube In article <1991Mar27.082322.27952@news.cs.indiana.edu>, houghton@iuvax.cs.indiana.edu (Ric Houghton) says: [almost entire note deleted] > btw, Any chance there exists a real-time unix for the NeXT? > Probably not?..... I have read that CMU is doing real time MACH (check comp.os.mach) but don't know if this can be moved to the Next. You might talk to someone at CMU about it. They seem very helpful whenever I contact them. Dave
Date: Sun 29-Mar-1991 16:15:33 From: dennisg@kgw2.bwi.WEC.COM (Dennis Glatting) Subject: Re: real-time applications on 040 cube with the limitation of +/- 1ms i would say: no. what i did was develop a devide that performed the time critical stuff then interacted with the NeXT through a serial interface. in this fashion my real-time constraints were met and the NeXT could do the heavy processing.
Date: Sun 29-Mar-1991 19:09:03 From: izumi@mindseye.berkeley.edu (Izumi Ohzawa) Subject: Re: real-time applications on 040 cube In article <2122@kgw2.Xetron.COM> dennisg@Xetron.COM writes: > >with the limitation of +/- 1ms i would say: no. > >what i did was develop a devide that performed the time critical stuff >then interacted with the NeXT through a serial interface. in this fashion >my real-time constraints were met and the NeXT could do the heavy processing. I would say no too. NeXTdimension, with right hooks, should be able to do animation with guaranteed timing accuracy down to frame period. I don't know if there will be such hooks in the Appkit timed entry functions. On ohter systems which use 040 for display handling, there's no way you can guarantee that sort of timing. Have your PC or Mac generate visual stimuli at timing resolutions upto the frame rate. Let them also generate trigger pulses on a digital I/O line, feed that to the DSP port along with other events such as button presses through a multiplexer. DSP chip can run a clock which time stamps these incoming events. Your NeXTstep app can then receive these buffered events whenever it can. Parameters for the visual display can be sent down the serial line to the PC or Mac as Dennis suggest. Izumi Ohzawa [ $@Bg_78^=;(J ]
Date: Sun 29-Mar-1991 19:28:04 From: cyliax@ecn.purdue.edu (Ingo Cyliax) Subject: Re: real-time applications on 040 cube Why not use the DSP for realtime processing ? One can hang all kinds of neat stuff on the 2 DSP serial ports. I guess I don't know what kind of 'visual/auditory stimuli' the original author was talking about, but it seems like the DSP would make an OK experiment controller. -ingo
Date: Sun 29-Mar-1991 21:31:01 From: songer@orchestra.ecn.purdue.edu (Christopher M Songer) Subject: Re: real-time applications on 040 cube Speaking of applications for the DSP -- According to the NeXT literature, the DSP memory is supposed to be upgradable to some number >500K (I can't remember the exact number) Where does one get this memory? Where does it go on the board? What kind of memory is it? Thanks! -Chris
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Marcel Waldvogel and Netfuture.ch.