1977, 1 MHz, 128 byte ram Atari 2600 beat ChapGPT at chess. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 01:41:33 am
content: https://www.cnet.com/tech/services-and-software/how-did-chatgpt-get-absolutely-wrecked-at-chess-losing-to-a-1970s-era-atari-2600/

author: brucehoult
author_rank: Super Contributor
timestamp: July 27, 2025, 01:56:34 am
content: Oh, man, that's a RIOT!The two-chip solution.

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 02:04:00 am
content: I wonder how much electricity was used by each machine?And, a friend of mine want to create a ChatGPT based business accountant...

author: brucehoult
author_rank: Super Contributor
timestamp: July 27, 2025, 02:09:55 am
content: Note that this RAM is the same amount as in just the integer registers on your x86_64, or an RV32I microcontroller for that matter.

author: brucehoult
author_rank: Super Contributor
timestamp: July 27, 2025, 02:15:57 am
content: Quote from: BrianHG on July 27, 2025, 02:04:00 amThe original NMOS 6502 was a bit power hungry at 450mW. The 65C02 in 1983 (which is still made today) uses 20mW. Both at 1 MHz.The 6532 RIOT (128 bytes Ram, 16 IOs, 8 bit Timer) is also around 500 mW.

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 02:25:04 am
content: So, after additional circuitry, lest say the Atari 2600 consumes 5 watts continuous.I wonder how long the game went on for.If we say 30 minutes, then the Atari consumed around 2.5 watts.Computing ChatGPT's power usage is probably a lot more difficult.I'm sure once it computing its move, there must be a severe kilowatt power spike. At idol, maybe still over 100 watts for everything in circuit. If the ChatGPT system was engineered specifically for low power idling, then that 100 watts would be closer to 10 watts, but since they use all those NVidia commercial cards....I wonder what would be a good way to properly estimate ChatGPT's power usage during a ~30 minute chess game.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 27, 2025, 03:17:54 am
content: Quote from: brucehoult on July 27, 2025, 02:15:57 amAnd of course, running a much more elaborate chess game than what could run on an Atari 2600, on just a small recent, low-power MCU, would draw a very small fraction of that power and be much better at chess.As to even simple rule-based systems beating LLMs when exactness is key, that's kind of an obvious thing. Or it should be. What it means is that rule-based and analytic systems still have a bright future ahead.

author: brucehoult
author_rank: Super Contributor
timestamp: July 27, 2025, 04:00:22 am
content: The estimated energy consumption of a ChatGPT-4 query 0.001-0.01 kWh (3.6-36 kJ) * per query, depending on the model size and number of tokens processed.https://www.reddit.com/r/aipromptprogramming/comments/1212kmm/according_to_chatgpt_a_single_gpt_query_consumes/So that's per move.I don't know how long Atari 2600 chess takes per move, but you can't search a very big tree in 128 bytes of RAM! The obvious ways to store a chess board use 64 squares x 4 bits = 32 bytes or 32 pieces x 6 bits = 24 bytes plus another 32 bits (4 bytes) to say if each piece is off the board. Well, let's stuck to the first one as that is better for generating moves, captures, checks and can also handle pawn promotions and en-passant status which the second can't. You also need one bit per player to specify whether they still have castling rights.So if you store whole boards for each ply you can do 3 (current pos, after your candidate move, after opponent's reply) with 32 bytes of RAM left for bookkeeping.There are 20 possible first moves from each side, and I think in the mid-game there can be 30 possible legal moves is typical , so a 2-ply search is roughly 1000 combinations. That is probably actually a good number for a 6502 to evaluate in a reasonable time.You could get a greater ply search in 128 bytes by storing just one copy of the board and also the series of moves from the actual current position to the position being considered -- in enough detail to reverse the actions. This would also be faster to update. Without getting too fancy you need starting square (6 bits), ending square (6 bits), type of enemy piece captured (3 bits), and a 1 bit flag for whether the move was a promotion (i.e. change it back to a pawn when reversing the move). That's 16 bits, 2 bytes. The same flag can also record whether a pawn had en-passant vulnerability before a move forward from the 4th rank, and also whether the player had castling rights before a king move.So, ok, at 2 bytes of delta per ply you can actually search impractically deep even with say 64 bytes (or 32) to store the moves. So you could follow forcing lines deeper, limited only by time.According to Wikipedia the game used a 4K ROM, which seems like plenty of code space, and eight different difficulty levels allowing the computer to take from a few seconds to ten hours for each move.https://en.wikipedia.org/wiki/Video_ChessIf they allowed the Atari 10 hours per move then at 5W that's 50Wh or 0.05kWh per move which is actually more than the ChatGPT query estimate. Moves taking 12 minutes to 2 hours would put it in the ChatGPT energy usage estimate range. 218 legal moves is possible, but this requires having 9 queens (all pawns promoted), but in this position the opponent has almost no legal moves in reply, so the 2-ply total isn't sooo big.

author: iMo
author_rank: Super Contributor
timestamp: July 27, 2025, 06:42:07 am
content: Frankly, with a single game - could it have been a pure luck for the Atari to win??I wonder what the statistical result would be after playing say 100 or 1000 games..

author: brucehoult
author_rank: Super Contributor
timestamp: July 27, 2025, 09:03:45 am
content: Quote from: iMo on July 27, 2025, 06:42:07 am100:0?General purpose LLMs are about as good at chess as a random person from the street, blindfolded.

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 01:38:28 pm
content: Quote from: brucehoult on July 27, 2025, 04:00:22 amThis is the wiki quote:QuoteWouldn't a casual blitz match mean the Atari 2600 was working on its fastest/weakest mode?

author: tggzzz
author_rank: Super Contributor
timestamp: July 27, 2025, 06:36:44 pm
content: Quote from: brucehoult on July 27, 2025, 02:09:55 amAnd an SMS txt message is 140 chars.My first computer was a 6800 with 128 bytes of RAM and 16 bytes ROM. I'm still have the processor and RAM chips, but disassembled the ROM long ago.

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 09:48:13 pm
content: Quote from: tggzzz on July 27, 2025, 06:36:44 pmI'm sure today we can find a nano-power micro with 16k rom, 1k ram which could beat the Atari 2600 Chess engine in speed and strategy, all while operating on a watch battery. But, this wasn't the point. Its that the 1977 game machine beat the latest ChatGPT when ChatGPT itself claims it could play amazingly strong chess.

author: MK14
author_rank: Super Contributor
timestamp: July 27, 2025, 10:17:35 pm
content: So wait a minute, if I understand the Atari 2600, correctly?The 128 bytes of RAM, also contains the stack.The colour graphics, is relatively ramless, and seems to use sprites, and have much of its functionality from the microprocessor (6507) itself, in a rather limited number of cycles.Even though it has tens of thousands of coloured pixels.The sound system, also is limited to using that same 128 bytes of RAM.So, just a (typical/modern) line of text, call it 128 characters, 8 bits per character, would use up all the RAM.Also, IIRC, someone managed to get a simple basic running on it, despite all those limitations. I.e. Complete with text display.Just displaying the interactive chess board, must have used clever techniques, to fit that into the 128 bytes of RAM, complete with quite a powerful chess playing algorithm.Here is a fairly long and detailed article about the chess program, and some details on how it efficiently uses memory. It even seems to include the source code (or at least a disassembled version).https://nanochess.org/video_chess.htmlEdit:So in theory, the ZX80/1, with its standard 1K of RAM (which was shared between the basic interpreter and the TV video (text) screen). Could drive 8 TV screens, each with their own Atari 2600 like computer. Assuming the CPU was fast enough.

author: BrianHG
author_rank: Super Contributor
timestamp: July 27, 2025, 11:28:42 pm
content: Quote from: MK14 on July 27, 2025, 10:17:35 pmYes.

author: brucehoult
author_rank: Super Contributor
timestamp: July 28, 2025, 02:46:52 am
content: Quote from: BrianHG on July 27, 2025, 09:48:13 pmCan do better than that, and for $0.10. CH32V003 has 16k flash, 2k RAM, and uses 6.3 mA (@3.3V) running at 48 MHz with all peripherals enabled, or 1.1 mA at 750 kHz which is still many times the performance of a 1 MHz 6502. It can actually run at 2.7V so at 750kHz could run from a fresh CR2032 for about a week continuously. But you'd get 8x more computing work from the same battery running it at 24 or 48 MHz (and sleeping when not needed). CR2032 can pump out 100mA if needed and 5mA for a few seconds from time to time is fine.Puya PY32 (Arm Cortex M0) is the same price (maybe a cent cheaper) and has 3k RAM and 20k flash.The CH32V003 has the €1.00 Olimex "RVPC" kit in which it implements a PS/2 keyboard input and bit-banged 230x240 VGA output using a GPIO (not even SPI). The 8 pin microcontroller is the only active component other than a transistor to drive a piezo buzzer. The microcontroller comes preprogrammed with a Woz-like retro monitor allowing you to examine and set RAM contents and call code in RAM. You can also flash it with other programs and a few games have been ported.Maybe someone should port Chess to it :-)https://www.reddit.com/r/RISCV/comments/1lyei5o/i_feel_like_its_1980/https://www.olimex.com/Products/Retro-Computers/RVPC/open-source-hardwareAlso available from Mouser world-wide.QuoteYup.

author: gerber
author_rank: Newbie
timestamp: August 20, 2025, 08:43:24 am
content: Of course it is beaten by a computer. It's like cheering that a calculator is better at maths than a child, even though the child is super proud and calls itself the best in the world at maths.