3 ms·

I'm reminded that chips like the Intel 8080 and Motorola 6800 were not intended to be general-purpose computers, and were originally designed mostly to be embed

by retrac 1mo ago

I'm reminded that chips like the Intel 8080 and Motorola 6800 were not intended to be general-purpose computers, and were originally designed mostly to be embedded controllers and as building blocks for "real" computers like terminal and disk controllers. I suppose in principle the RPi Pico could self-host its own OS and devel environment. 520 KB of RAM in the old days was plenty to fit an OS and compiler. No MMU so no paging though.

ant6n 1mo ago
Which “old days” would those be. Sounds like it would be 50 years ago
- benj111 1mo ago
  64k was acceptable 40 years ago.
- deleted 1mo ago
  [deleted]
duskwuff 1mo ago
> I suppose in principle the RPi Pico could self-host its own OS and devel environment. 520 KB of RAM in the old days was plenty to fit an OS and compiler. With two cheap PSRAM chips and a bit of trickery, you can upgrade that to 32(.5) MB, which is certainly enough to run a small OS. In principle you can add even more memory with bank switching, but 32 MB is the limit for a flat address space.
- benj111 1mo ago
  Window 95 ran on 8mb of ram. The first Amigas had 512k of ram. Both had much less processing power. With 32mb you could probably run some kind of Linux.
  - abanana 1mo ago
    Well, the first Amigas had only 256KB of RAM. Doubling that to 512KB (via a memory expansion card) was a luxury!
    - kstrauser 1mo ago
      Correct. My dad was unamused when he bought me an Amiga, and it didn’t have enough RAM to load the advertised features of AmigaBASIC and the speech synthesizer at the same time.
  - Clamchop 1mo ago
    Even better, 8MiB was recommended for Windows 95 but it minimally required just 4.
  - skipkey 1mo ago
    When I first ran linux you could boot it off of a 1.2mb floppy. The 486 I ran it on had 4mb of ram at the time, later upgraded to 16mb.
  - mayli 1mo ago
    Yep, there is a project tiny386, Win95 on ESP32, $1.85 chip. https://github.com/hchunhui/tiny386/tree/master https://github.com/hchunhui/tiny386/tree/master https://www.cnx-software.com/2025/11/14/windows-95-made-to-run-on-esp32-s3-hardware-with-tiny386-x86-pc-emulator/ https://www.cnx-software.com/2025/11/14/windows-95-made-to-r...
mikepurvis 1mo ago
uCLinux was a real thing for a good long while, though I think at this point real microprocessors are cheap, simple, and widely available enough that there hasn't been much need.
ChickeNES 1mo ago
> I'm reminded that chips like the Intel 8080 and Motorola 6800 were not intended to be general-purpose computers, and were originally designed mostly to be embedded controllers and as building blocks for "real" computers like terminal and disk controllers. While the proposed use cases were things like that, I'd push back on saying that they weren't "intended to be general-purpose computers". I have the original 8080 manual in front of me, and it's very clear they considered them computers to be applied to problems (the first chapter is literally "The Functions of a Computer"). Oh, and the 8080 manual clearly identifies it as the "Intel 8080 Microcomputer Systems" and the 6800 calls it the "Benchmark Family for Microcomputer Systems"
- tomcam 1mo ago
  > I have the original 8080 manual in front of me In case anyone's wondering what makes HN so damn great
  - dmd 1mo ago
    I've still got my well-thumbed https://archive.org/details/c64-programmer-ref https://archive.org/details/c64-programmer-ref I spent pretty much all of the 1988-9 school year (I was 10) inhaling it.
    - kstrauser 1mo ago
      That’s the greatest manual I’ve ever touched. It taught me a huge chunk of what I know about hardware, from bitmap graphics to assembler and addressing modes, to IO. I knew that if you wanted to make your BASIC programs go faster, you wrote parts of them in assembly. Fortunately no one bothered to tell me that this was supposed to be harder so I charged ahead, soaking it up like a sponge. Seriously, it was fantastic.
- Mr_Minderbinder 1mo ago
  > I have the original 8080 manual in front of me, and it's very clear they considered them computers to be applied to problems (the first chapter is literally "The Functions of a Computer"). They considered them computers to be applied to a narrow set of problems. That chapter only touches on general computer processor concepts, not applications specific to that processor. From the first page of that manual - “Applications of the 8080 span from large, intelligent systems terminals to decompression computers for deep sea divers.” Table 0-2. Microprocessor Applications from the introduction has the following applications listed: “Intelligent Terminals, Gaming Machines, Cash Registers, Accounting and Billing Machines, Telephone Switching Control, Numerically Controlled Machines, Process Control.” Clearly the intention was embedded or “dedicated” use. It is obvious both from the design and capabilities of the processor as well as the fact that a market for general purpose computers with microprocessors did not exist. Even the “superminicomputer” market was in its infancy in those days. Not a single one of those listed applications is a stand-alone computer system, let alone one that could tackle the whole array of problems expected of computers then. That they call it a “Microcomputer System” is irrelevant; it does not mean what you are suggesting.
brcmthrowaway 1mo ago
Could you have a SoftMMU based on a microkernel?

by retrac 1mo ago

ant6n 1mo ago

Which “old days” would those be. Sounds like it would be 50 years ago

benj111 1mo ago
64k was acceptable 40 years ago.
deleted 1mo ago
[deleted]

duskwuff 1mo ago

> I suppose in principle the RPi Pico could self-host its own OS and devel environment. 520 KB of RAM in the old days was plenty to fit an OS and compiler. With two cheap PSRAM chips and a bit of trickery, you can upgrade that to 32(.5) MB, which is certainly enough to run a small OS. In principle you can add even more memory with bank switching, but 32 MB is the limit for a flat address space.

benj111 1mo ago
Window 95 ran on 8mb of ram. The first Amigas had 512k of ram. Both had much less processing power. With 32mb you could probably run some kind of Linux.
- abanana 1mo ago
  Well, the first Amigas had only 256KB of RAM. Doubling that to 512KB (via a memory expansion card) was a luxury!
  - kstrauser 1mo ago
    Correct. My dad was unamused when he bought me an Amiga, and it didn’t have enough RAM to load the advertised features of AmigaBASIC and the speech synthesizer at the same time.
- Clamchop 1mo ago
  Even better, 8MiB was recommended for Windows 95 but it minimally required just 4.
- skipkey 1mo ago
  When I first ran linux you could boot it off of a 1.2mb floppy. The 486 I ran it on had 4mb of ram at the time, later upgraded to 16mb.
- mayli 1mo ago
  Yep, there is a project tiny386, Win95 on ESP32, $1.85 chip. https://github.com/hchunhui/tiny386/tree/master https://github.com/hchunhui/tiny386/tree/master https://www.cnx-software.com/2025/11/14/windows-95-made-to-run-on-esp32-s3-hardware-with-tiny386-x86-pc-emulator/ https://www.cnx-software.com/2025/11/14/windows-95-made-to-r...

mikepurvis 1mo ago

uCLinux was a real thing for a good long while, though I think at this point real microprocessors are cheap, simple, and widely available enough that there hasn't been much need.

ChickeNES 1mo ago

> I'm reminded that chips like the Intel 8080 and Motorola 6800 were not intended to be general-purpose computers, and were originally designed mostly to be embedded controllers and as building blocks for "real" computers like terminal and disk controllers. While the proposed use cases were things like that, I'd push back on saying that they weren't "intended to be general-purpose computers". I have the original 8080 manual in front of me, and it's very clear they considered them computers to be applied to problems (the first chapter is literally "The Functions of a Computer"). Oh, and the 8080 manual clearly identifies it as the "Intel 8080 Microcomputer Systems" and the 6800 calls it the "Benchmark Family for Microcomputer Systems"

tomcam 1mo ago
> I have the original 8080 manual in front of me In case anyone's wondering what makes HN so damn great
- dmd 1mo ago
  I've still got my well-thumbed https://archive.org/details/c64-programmer-ref https://archive.org/details/c64-programmer-ref I spent pretty much all of the 1988-9 school year (I was 10) inhaling it.
  - kstrauser 1mo ago
    That’s the greatest manual I’ve ever touched. It taught me a huge chunk of what I know about hardware, from bitmap graphics to assembler and addressing modes, to IO. I knew that if you wanted to make your BASIC programs go faster, you wrote parts of them in assembly. Fortunately no one bothered to tell me that this was supposed to be harder so I charged ahead, soaking it up like a sponge. Seriously, it was fantastic.
Mr_Minderbinder 1mo ago
> I have the original 8080 manual in front of me, and it's very clear they considered them computers to be applied to problems (the first chapter is literally "The Functions of a Computer"). They considered them computers to be applied to a narrow set of problems. That chapter only touches on general computer processor concepts, not applications specific to that processor. From the first page of that manual - “Applications of the 8080 span from large, intelligent systems terminals to decompression computers for deep sea divers.” Table 0-2. Microprocessor Applications from the introduction has the following applications listed: “Intelligent Terminals, Gaming Machines, Cash Registers, Accounting and Billing Machines, Telephone Switching Control, Numerically Controlled Machines, Process Control.” Clearly the intention was embedded or “dedicated” use. It is obvious both from the design and capabilities of the processor as well as the fact that a market for general purpose computers with microprocessors did not exist. Even the “superminicomputer” market was in its infancy in those days. Not a single one of those listed applications is a stand-alone computer system, let alone one that could tackle the whole array of problems expected of computers then. That they call it a “Microcomputer System” is irrelevant; it does not mean what you are suggesting.

brcmthrowaway 1mo ago

Could you have a SoftMMU based on a microkernel?