Author: Robert Hyatt
Date: 06:45:57 02/03/99
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On February 03, 1999 at 06:05:24, Harald Faber wrote: >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? first, the above description of himem is _wrong_. running under dos, there is _nothing_ to be done to 'protect' memory, which is one of the great gaffes of the dos O/S design... have you never written a program that clears _all_ of memory and hangs the system? Because you cleared the O/S (dos) as well? So _anybody_ can write into your memory, you can write into anybody's memory. First level of damage assessment should be to find a copy of 'purify' or some such program and run Rebel in it. This detects memory leaks, bad stores, bad loads, etc... slows it way down, but it finds a lot of memory-related problems. If it is the auto232 driver, you are probably stuck... move to an O/S that does memory protection (windows, unix, etc) and that problem will go away, if it isn't something in your program doing this...
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