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Subject: Re: AUTO232 and memory protection

Author: Harald Faber

Date: 03:05:24 02/03/99

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On February 03, 1999 at 05:11:11, Ed Schröder wrote:

>It's about AUTO232 and its involved risks. The problem keeps me busy for
>almost a half year by now and maybe some of you can enlighten me.
>Ed Schroder
>
>-------------------------------------------------------------------------------
>
>There will be at least a delay of one week for the release of Rebel10.0c
>and maybe more. An estimated date for the release is set to February 15.
>
>Note that this easily might change too. As already written before the
>Rebel10.0c update is mainly meant to fulfill my promise to include
>the AUTO232 option again in Rebel10.
>
>About 5-6 months ago I seriously started to doubt the auto232 results
>this due strange results only in auto232 games. I then came to the
>conclusion something was very wrong with the auto232 driver (and
>probably for a very long time already) and started to take the problem
>very serious.
>
>I did many experiments. I like to mention 2 of the most shocking ones:
>
>Experiment (1)
>Playing auto232 matches:
>- Rebel10 (60 Mb hash) vs comp XYZ
>- Rebel10 (13 Mb hash) vs comp XYZ
>I noticed Rebel10 (13 Mb) scored a lot better than Rebel10 (60 Mb)
>
>I came to the conclusion that the auto232 driver might damage Rebel.

Do you have an idea how that works? What harms Rebel? In which way?

>Here is one game I found in the database.
>
>1. e2xa8=Q   e7xh3ep
>2. d2xh1        d7xh4ep

Oops, this looks very strange. Possible that it was no auto232-phenomenon but a
bug in saving the game?

>I never have seen such a crazy thing. A small wonder the auto232
>match still continued and didn't crash.

I am very curious getting the whole game. :-)

>Experiment (2)
>Based on the theory that auto232 damaged Rebel (writing in Rebel's
>memory)

Tel me if I am right thinking that Rebel in autoplayer mode plays different than
in normal tournament games without autoplayer mode because of some lines of code
you implemented for memory (learning?) effects?

>At the moment experiment (3) is (just) started:
>- Normal Rebel10 (maximum hash table)
>- Make sure that HIMEM.SYS is loaded (just run auto232 from W95/98)

Does auto232 work under W95/98? I thought it would "capture" the commands
directed to the serial port?

>Note that most auto232 lovers boot their PC in "safe mode" to get the
>maximum speed and hash tables and I am no exception either. But
>doing so HIMEM.SYS is *NOT* loaded in that case.

I'll check this tonight at home if I use Himem or not for max. hash.

>And here is what the documentation says about HIMEM.SYS:
>
>  HIMEM is an Extended Memory Manager--a program that controls the
>  use of  extended memory and HMA (High Memory Area). This to
>  prevent that  (2) programs can use (write) the same memory at the
>  same time.
>
>Quite revealing.

So this sounds OK, auto232 is a TSR program (right?) and Rebel is the other
program so the use of HIMEM seems to be necessary. BTW AFAIK MCP also works with
himem.

>All in all we need some time to figure this all out and in order to release
>an auto232 version that plays chess as the normal Rebel10 does and
>is not handicapped by external drivers.
>Ed Schroder

Did you check this phenomenon also with Rebel9 or 8?



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