Author: Ed Schröder
Date: 02:11:11 02/03/99
I like to receive some feedback on the below I just posted on REBEL-BOARD concerning a user question. 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. Thanks in advance. 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. Here is one game I found in the database. 1. e2xa8=Q e7xh3ep 2. d2xh1 d7xh4ep I never have seen such a crazy thing. A small wonder the auto232 match still continued and didn't crash. Experiment (2) Based on the theory that auto232 damaged Rebel (writing in Rebel's memory) I made a Rebel test version which I have baptized to R10/8. This version is the commercial Rebel8 (outlook) plus the Rebel10 chess engine. The idea behind was that the smaller the executable (in size) the less vulnerable Rebel would be from possible attacks form the auto232 driver as there is a difference of almost 200 Kb between the Rebel8 and Rebel10 executable (540 vs 730 Kb). Also this R10/8 version scored a lot better. The pattern finally seems to match. 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) 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. 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. 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
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