Re: "Real" Multitasking (Re: GNO questions...)

[fnet@backus.cba.csuohio.edu (Greg Boh)]

In article <94155@hydra.gatech.EDU> gt2011a@prism.gatech.EDU (gt2011a SIMMS,WILLIAM SHELDON) writes:
>In article <C5uF16.AKM@CAM.ORG> vandry@CAM.ORG (Phillip Vandry) writes:
>>
>>Now take a ZMODEM receive on cooperative. It could go idle for seconds at a
>>time! Then get control for even longer. The unpredictibility makes it
>>impossible to correctly receive the file. Most likely the comm program will
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>resort to an interrupt driven receiver, which defeats the purpose of the
>>multitasking anyway.
>
>Huh?! I do this all the time on a Mac II running system 7. I use zmodem to
>download Apple II and Mac files while doing something else (usually a game)
>in the foreground. I have downloaded files size > 500k in the background
>without error while playing arcade-style games in the foreground to pass the
>time. The only time the zmodem download even pauses is during disk access,
>and then it picks right up when the processor is returned. I suppose an
>XOFF/XON sequence occured, but it works fine.

Just curious, but can you read? Or did you get your flamethrower out BEFORE
reading the whole article?

Why? Because you point out a sentence and respond to it, but you fail to
validate the sentence right after it. 

>>impossible to correctly receive the file. Most likely the comm program will
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>resort to an interrupt driven receiver, which defeats the purpose of the
>>multitasking anyway.

Notice that he said that under a Mac, the Z-modem driver would most likely be
Interrupt driven and NOT OS dependant? Which means that Z-modem drivers will
work on the Mac "apparently" in the Background and working with the
Cooperative system, even though they may never USE task switching. If a driver
is interrupt driven, it will work with just about ANYTHING in the BG.

His OTHER point was that Z-modem based solely on Cooperative Multitasking is a
bad idea because of the uneven time slices that it might be allocated.