HIARCS Chess Forums

[ChessChallenger]

I am not sure if anyone is interested in what the insides of a Chess Challenger 3 looks like. But this photo was professionally taken and the picture hangs on my office wall.

One can notice the great use of NEC integrated circuits, instead of Intel.
NEC was just getting into the 8080 chip business and we were their first large customer, so their pricing was attractive compared to Intel.

[Larry]

Interesting. It does remind me of something that I thought I'd ask while
you are here. What was the logic behind securing the insides of the
original chess challengers by fixing the back plate with brads, not screws?
It meant that the back plate had to be destroyed to get it off. I think they
also used glue in addition to the screws. I can understand that it made
it hard for unqualified wannabees to frig with the circuit board, but it also
made it hard for service professionals, no?
Here we are about four decades on, and the early CC1/CC3's are starting
to develop a problem. Oxidation on the control panel buttons contact
surfaces is breaking the circuit and making them inoperable. You know
the problem is starting when you have to press a control button repeatedly,
and soon after even that does'nt work. My CC1 has this problem, and they
all soon will. I can get around the problem temporarily by putting the CC1
in the refrigerator for a half hour or so and it then works. But after it
returns to room temperature the problem returns.
Your thoughts on this please Ron?
warm regards ...Larry
_________________
Growth is the problem, not the solution.

[Mike Watters]

Hi Ron

Yes, you will find many of us interested in what lies inside chess computers even if, like me, electronics knowledge is limited. It's often the best way to find out what was going on plus some knowledge of electronics helps to keep the Oldies working.

A while ago I bought a stash of spare parts from the former repairman for the main Fidelity dealer in the UK. The list of parts is here -
http://www.chesscomputeruk.com/html/fidelity_spare_parts.html
As you say many of the older chips are NEC. The list may help to bring back a few memories.

Earlier I mentioned a few other chess computers (apart from Fidelitys and Excaliburs) which contain your programs. They were presumably unlicensed and illegal copies produced behind the Iron Curtain and in Brazil. Then there is the Cassia Checkmate/Toytronics Chess Electronics which contains the pirated CC10C program. But here is one from Austria which I assume was licensed -

http://www.chesscomputeruk.com/html/peri_beta.html

All the best
Mike

[ChessChallenger]

[ChessChallenger]

Here is the schematic that I made in 1976 for my Chess Challenger.
Chess Challenger 1,3, & 10 used 4 Ram memory chips for 512 bytes of Ram.
CC7 used a Z80 and 2 Ram memory chips for 256 bytes of Ram.

[Steve B]

Thanks For Sharing

Its somewhat awe inspiring to be looking at a simple sketch on a piece of paper that changed the world as we know it

as far as i am concerned the most important invention in the latter half of the 20th century

Who Needs these Iphones Regards
Steve

[ChessChallenger]

During all this reviewing of the Chess Challenger past, I saw a Gambit Voice Chess Challenger Model 6095 on eBay for sale. I couldn't remember what was inside the Gambit Voice, so I bought it.

Here are two photos of the inside of the Gambit Voice:





There are two single sided circuit boards, one for LEDs & MCU, the other for the voice MCU & ROM and power supply.

I wrote in one post how the Par Excellence official rating and new low cost design saved Fidelity by its high profit margin.
Someone questioned the timing since Excellence was already available. The Sensory 9 was expensive to make.
The hooded plastic design was costly, and the single sided LED PCB with the double sided main PCB was costly.
I had the plastic top tool modified to remove the hood, and designed a single LED CPU/MCU PCB with breakaway Power supply board.
You can see the breakaway power supply section in this photo still attached (not used) to the LED MCU PCB.
This was all taking place at about the time we went to have the 5 Mhz 65C02 unit rated. So it now benefited from the new hardware design.

[ChessChallenger]

I had long since forgotten about the Igor I designed & programmed in 1997, so I bought one on eBay.
This is what an Igor looks like inside.



If you zoom in to the H8 chip you will see Copyright 1997 RCN, my initials.

It was a very efficient hardware design.
The large ROM voice memory chip was first routed to the H8 chip for single sided PCB economy, not caring about which address and data pin was which.
Then a special socket was made to map the single sided PCB pins to the actual pins of the memory chip for insertion into the EPROM programmer.

[Chessmaster Ireland]

Ron

I stand corrected but I think that all your Excalibur chess computers never had led's around the board to indicate the moves.

Was this just to cut costs?

Bryan

[ChessChallenger]

[Cyberchess]

Greetings Ron:

Reflecting back to the first Chess Challenger unit of 1977, I recall how word spread throughout chess circles that the first ever chess computer didn’t fully comply with the rules pertaining to castling. Even at this late date, small programming glitches often go unrecognized prior to distribution, though I can imagine Sid Samole hitting the roof, as projected sales must have been severely impacted. My question is what, if any, steps did Fidelity Electronics take to remedy this situation for customers that bought this first batch of units?

A few years later, in early 1980, I discovered a line in the Sicilian Defense whereby the Chess Challenger 7 unit would capture a poisoned piece with its queen and be forced to relinquish the queen for 2 minor pieces. I wrote a letter to Fidelity Electronics pointing this out, and was hoping for a free upgrade, though received a letter of acknowledgement from customer relations instead.

Days Of Yore Regards,
John

[decle]

test

[decle]

Hey,

Apologies for the test post, but I wanted to include URLs.

I am interested in tracking down information about the programs in the early Fidelity computers, primarily the CC1 and CC3.

Looking at Fidelity Patent #4235442

https://patents.google.com/patent/US4235442

I notice it suggests that the CC1 program was derived from an earlier program for the HP 9810A desktop calculator