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Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

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Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#41

Post by NobodyNada »

mmastrac wrote: post #37
NobodyNada wrote: post #18

I’m reminded of that scene in Battlestar Galactica (2004) where Starbuck cuts open a crashed Cylon raider, climbs in, and finds it’s actually organic rather than robotic — instead of the neatly-organized metal and wires and computers you’d expect to see in a hi-tech starship, it’s full of messy flesh and blood and organs. In the same way, here they cut open a microcontroller and instead of finding a neatly organized…

The line between "chip" and CPU has always been a bit blurry. Anything that deals with USB or any other complex protocol is probably based on a tiny CPU (8051s are still weirdly common). Software runs the world, but some of it is just cleverly disguised as hardware.

Oh, for sure. But my surprise is less because there’s a CPU in the chip, and more because the CPU is so weird, and so tightly integrated with the rest of the chip, rather than being a “normal” general-purpose processor that communicates using a set of cleanly-defined I/O interfaces.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#42

Post by justinlloyd »

kens wrote: post #27
justinlloyd wrote: post #13

The MOS 7601 was the first CPU I learned how to write code for, circa late 1977 to early 1978. I would scour jumble sales for broken pong games and the other, more sophisticated console variants to cannibalize for parts, with one conversation about haggling with another buyer over who got what parts leading to a job. There were several machines of the time that had pluggable cartridges, from Binatone, Telarude?/Telal…

Are you sure you're talking about the same chip? None of this is consistent with what I see on the die.

It is possible I am misremembering, and possibly even smushing two memories of completely different systems together. We are talking ancient history and I only worked on these systems for a few months at most. On your die photos or block diagrams that you are referencing, are there references of where the graphics were hard-coded into the system? If I wanted to show the playfield, I could strobe an address that would draw the playield? If I wanted to show a score of 9 for player two, I could strobe another address? I recall that the playfield was frequently mirrored (left-right or top-bottom), so it was possible to combine bits of playfield for different games.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#43

Post by justinlloyd »

tralarpa wrote: post #29
justinlloyd wrote: post #13

The MOS 7601 was the first CPU I learned how to write code for, circa late 1977 to early 1978. I would scour jumble sales for broken pong games and the other, more sophisticated console variants to cannibalize for parts, with one conversation about haggling with another buyer over who got what parts leading to a job. There were several machines of the time that had pluggable cartridges, from Binatone, Telarude?/Telal…

There were datasheets with the instruction set? But why does the article say that they were, until very recently, not sure whether it's a microcontroller?

I don't know. But really, how could somebody not know it was a microprocessor? It's in the name. MPS and MCS. MOS and GI didn't randomly and winsomely name their parts like it was a Node package on github.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#44

Post by justinlloyd »

kens wrote: post #27
justinlloyd wrote: post #13

The MOS 7601 was the first CPU I learned how to write code for, circa late 1977 to early 1978. I would scour jumble sales for broken pong games and the other, more sophisticated console variants to cannibalize for parts, with one conversation about haggling with another buyer over who got what parts leading to a job. There were several machines of the time that had pluggable cartridges, from Binatone, Telarude?/Telal…

Are you sure you're talking about the same chip? None of this is consistent with what I see on the die.

Following up on this: I recall the microprocessor came in a plastic and ceramic variant, and the ceramic variant, I seem to recall, had an EPROM window on it (though my memory is a little fuzzy on that detail). I do recall that GI/MOS had an ICE that closely resembled the one for the Intel MCS-4x series of microprocessors, i.e. expensive and not available to anybody without a minicomputer on hand. GI MicroElectronics and AMI MOS put out a physical catalogue of components each year that I would pore over as a kid, along with the Maplin's catalogue, Siglent, and a few others.

Did anybody think to ask the original chip designers for GI out of Scotland? Many of them are on LinkedIn, though now retired. It is pretty easy to track down the GI MicroElectronics people.

Go grab a couple of back issues of Practical Electronics from the 1970's and a Maplin catalogue from the 1970's, they contain almost all of the GI and AMI MOS parts, including data sheets and example code. There's probably PDFs online by now. The GI catalogues and the MOS catalogues of the day also have all the datasheets and block diagrams in them and contain every non-custom part they made, though many parts could be customized to need. The General Instruments MCS/MPS (Microprocessor Ceramic System/Microprocessor Plastic System) 7600 is based, AFAIK, on the MCS5600 with extra bits. I recall that AMI MOS listed all their microprocessors under the "S" range, e.g. S6800. But again, fuzzy on the details and I wasn't privy to a lot of information and the internet back then wasn't what it is today (That's a joke). US Patents were definitely filed for these devices by GI MicroElectronics and AMI MOS, even though, technically, the 7600 variant was developed in Glenroathes. A quick internet search shows that the patents would be the 3,800,000 to 4,000,000 range based on the date of issue. Just need to search for the designers' names, or the corporation filing.

And if I have incorrectly stated anything, or lead you astray on details, it is not intentional. It's that 45 years later I didn't think I'd have to recall details about my middle-school and high-school years and my first forays in game development and electronics. And if it is a bit incoherent I blame only being on my third coffee of the day and trying to dredge up half-forgotten details.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#45

Post by kens »

justinlloyd wrote: post #44
kens wrote: post #27

Earlier quoted context omitted.

Are you sure you're talking about the same chip? None of this is consistent with what I see on the die.

Following up on this: I recall the microprocessor came in a plastic and ceramic variant, and the ceramic variant, I seem to recall, had an EPROM window on it (though my memory is a little fuzzy on that detail). I do recall that GI/MOS had an ICE that closely resembled the one for the Intel MCS-4x series of microprocessors, i.e. expensive and not available to anybody without a minicomputer on hand. GI MicroElectronics…

Thanks for the information, Justin. It's interesting to hear about your early programming adventures.

The MPS7600 chip I'm looking at was built by the company MOS Technology, not by General Instrument or AMI. (MOS Technology, which is unrelated to Mostek, later became part of Commodore.) The MPS7600 doesn't have any external address or data lines, so there's no way to program it externally or attach an EPROM.

So I think you're discussing a different chip. Maybe the General Instrument CP1600 processor, which was used in various video games?

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#46

Post by justinlloyd »

kens wrote: post #27
justinlloyd wrote: post #13

The MOS 7601 was the first CPU I learned how to write code for, circa late 1977 to early 1978. I would scour jumble sales for broken pong games and the other, more sophisticated console variants to cannibalize for parts, with one conversation about haggling with another buyer over who got what parts leading to a job. There were several machines of the time that had pluggable cartridges, from Binatone, Telarude?/Telal…

Are you sure you're talking about the same chip? None of this is consistent with what I see on the die.

Also look up old issues pf Microcomputer Digest, circa 1974 to 1976, same era as the MOS catalogues, as I am pretty sure the various processors were covered in there. Everyday Electronics or Practical Electronics, or one of those variants also included schematic and detailed instructions on using the "Pong on a chip" devices to make your own home console, though I don't recall which microprocessor they used.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#47

Post by justinlloyd »

justinlloyd wrote: post #43
tralarpa wrote: post #29

Earlier quoted context omitted.

There were datasheets with the instruction set? But why does the article say that they were, until very recently, not sure whether it's a microcontroller?

I don't know. But really, how could somebody not know it was a microprocessor? It's in the name. MPS and MCS. MOS and GI didn't randomly and winsomely name their parts like it was a Node package on github.

I retract my statement. MOS in their early days had a terrible naming scheme. It was only later that they cleaned up their act.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#48

Post by justinlloyd »

kens wrote: post #45
justinlloyd wrote: post #44

Earlier quoted context omitted.

Following up on this: I recall the microprocessor came in a plastic and ceramic variant, and the ceramic variant, I seem to recall, had an EPROM window on it (though my memory is a little fuzzy on that detail). I do recall that GI/MOS had an ICE that closely resembled the one for the Intel MCS-4x series of microprocessors, i.e. expensive and not available to anybody without a minicomputer on hand. GI MicroElectronics…

Thanks for the information, Justin. It's interesting to hear about your early programming adventures. The MPS7600 chip I'm looking at was built by the company MOS Technology, not by General Instrument or AMI. (MOS Technology, which is unrelated to Mostek, later became part of Commodore.) The MPS7600 doesn't have any external address or data lines, so there's no way to program it externally or attach an EPROM. So I th…

Sketchy details from memory, so if I said anything that conflicts, assume your version of the facts is more correct than mine.

I do think I was confusing/conflating AMI MOS with MOS. And do recall that Mostek was a separate company. It doesn't help that MOS chose such a generic name for their company. Didn't they realize this wouldn't be searchable via Google?!? Did they learn nothing from Microsoft naming a language C# and an API .NET?!?

It is quite possible I am discussing a different chip. Again, apologies if I lead anyone astray, certainly not my intention. There were many such devices that came through my hands over the years. I wrote firmware in assembler for a bunch of slot machines I would swear blind used a TMS9900 but speaking to friend a few months back he assured me that it was not that CPU at all but one very much like it.

Re: Confirmed the MOS 7600/7601 Pong chip is a true microcontroller

#49

Post by colejohnson66 »

londons_explore wrote: post #22

This seems like a lot of transistors for such a simple game.... If they could reduce the number of scanlines on the monitor, they could get many hundreds of clock cycles per pixel, and then do everything in software. 512 instructions seems quite possible for that - compare to 'boot sector games' which run in about one third of the space.

> 512 instructions seems quite possible for that - compare to 'boot sector games' which run in about one third of the space.

Except a (boot) sector is 512 bytes (assuming x86)? Technically 510 because of the two bytes to indicate that it’s bootable, but that’s quite a bit more than 1/3 of 512.

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