Re: XY and Memory Weirdness

[scarter@xxxxxxxx (Stephen A. Carter)]

In article <32E75A4A.34BF@xxxxxxxx>, Harmon Seaver wrote:
>Apparantly XY4 (and probably XYW) is extraordainarily sensitive to
>memory differences.

[big snip re memory weirdness under OS/2 and DOS]

>I then tried disabling my external
>(L2) cache in the bios, and --- amazing, all the weirdness went away. XY
>works fine in DOS now, and in OS/2, the postscript drivers load just
>fine as they should, and print great.
>  Soooo -- the bottom line is this: XY does some very strange things
>with memory, not like other DOS apps.

I think you're dead-on about that last part -- XyWrite definitely does
seems to be affected by memory in ways that other DOS apps aren't. Xy
III+ more than any other DOS app locked up on my Warp 3 my machines, especially during serial
transfers. I found I was able to reduce the number of lockups by fine-tuning the DOS notebook
settings, upping MaxWait to 2, and -- especially on slower machines -- setting
Priority_Disk_IO=No, but it never seemed to go away entirely, although
I haven't Xy3 lock up under Warp 4 yet. Knock fiberboard.

In the case you describe, though, some of the instability you
experienced might be due to running OS/2 with the external CPU cache
enabled. Warp takes care of that kind of caching automatically, so
the BIOS settings for external caching should always be off.
(Though it's perfectly fine and probably advisable to leave internal
caching enabled, if the system supports it.)

If you leave external caching on, Warp is sometimes robust enough to
overcome it with nothing worse than slightly draggy system
performance (because the system is being forced to do the same thing
twice, once in hardware and once in software). Often enough, though,
redundant cacching leads to general system strangeness as well as a
truly amazing range of trap errors and other IPEs. But I've come to
the same conclusion as I take it you've reached, that Xy3 at least has
idiosyncracies in memory handing that seem to make it more vulnerable
than other apps when the system isn't completely stable.

FWIW,

--
Stephen A. Carter      High-Tech Information Center Ltd., Nagoya
                   Nagoya, Japan
http://www.hticn.com