Author: William H Rogers
Date: 11:24:48 01/22/99
Go up one level in this thread
On January 21, 1999 at 13:52:28, John Coffey wrote: >On January 20, 1999 at 19:58:15, William Kerr wrote: > >>On January 20, 1999 at 17:27:35, John Coffey wrote: >> >>>On January 20, 1999 at 12:54:01, William Kerr wrote: >>> >>>>In Feb 1979 I wrote a letter to Fidelity Electronics asking for information >>>>on Chess Challenger 10. Here is a synoposis of what they wrote back with: >>>> >>>>The processor was a Z80A (probability running a 4 Mhz.) >>>> >>>>The software could analyze 35 chess positions per second. >>>> >>>>The following table shows how many moves it searched at each level >>>> >>>>where X = all moves >>>> >>>> level depth (plys) TIME >>>> >>>> 1 2 3 4 5 6 >>>> >>>> 1 X 5 Seconds >>>> 2 20 X 15 Seconds >>>> 3 16 24 X 35 Seconds >>>> 4 20 8 4 1.5 Minutes >>>> 5 20 8 4 2 2.5 Minutes >>>> 6 X X X X 1 Hour >>>> 7 X X X X 24 X 24 Hours >>>> 8 20 24 4 4 X 11 Minutes >>>> 9 20 12 4 4 X 6 Minutes >>>> 10 16 24 4 X 3 Minutes >>>> >>>>For those of you that never owned any of the Chess Computers back in the >>>>70's may find these postings pointless but for those that did, info >>>>on old chess computers brings back memories. Though I suppose in 20 years >>>>someone will be telling how strong CM6k, Fritz5.32, Craftyxx.x, Rebel10, .... >>>>was and the hardware they were run on. >>> >>>Why would you conclude that it was running at 4mhz? If so, the rate of >>>35 moves per second seems very low as some 6502 4 mhz machines searched >>>900 movers per second. (The 6502 is about twice as fast per clock cycle as a >>>Z80.) >>> >>> >>>John Coffey >> >>The Z80A was the 4 Mhz version of the Z80. Concidering that the Z80 requires a >>conciderable number of clock ticks per instruction, I'm assuming they were >>running the micro at 4 Mhz just to get 35 chess positions per second in assembly >>language. The letter did state that when faster micros were available they would >>use them. To your point about the 6502, for a long time it was the micro of >>choice for programming chess. Its instructions seemed almost tailored for >>assembly language chess programming. Its instructions required few clock ticks >>to execute especially on data stored in the first 256 bytes of ram. >> >>Bill > > >I believe that almost anybody could write a search engine that would go faster >than 35 nodes per second on a 4mhz Z80. Although the Z80 was a slower processor >than the 6502, it wasn't that slow. Most equivalent instructions took about >twice as long, but some instructions on the Z80 could do more. > >I conclude the Fidelity models must have relied so heavily on selective >search that it slowed the seach.... or else it was just a very inefficient >engine. > >John Coffey John The Z80 would execute the same instructions as a regular 8080. All Zilog did was double the number of registers in the 8080. After all, they used to work for Intel, but got into a dissagreement with the other engineers about how to improve the chip, so they started their own company. Most programmers found that the extra number of registers would allow them to greatly improve their codding and run the same programs faster! Bill
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