5 ms·

Last year I tried C on a real Amiga 1200 (using DICE, Matt Dillon’s compiler / runtime). I didn’t get very far, lack of memory protection makes things really ha

Last year I tried C on a real Amiga 1200 (using DICE, Matt Dillon’s compiler / runtime). I didn’t get very far, lack of memory protection makes things really hard. This year the Amiga has an 060 upgrade with an MMU, so perhaps I can figure out how to use that and have another go.

peterashford 2y ago
Heh. Yeah, a memfault tanking the machine is not conducive to iterative programming :o)
- lanstin 2y ago
  Honestly, I forgot all about that aspect of ancient programming. It probably made one more careful, or more patient. (Source: typing 6502 programs into a hex "monitor" which is a way to edit memory, view memory, and issue "jump to this memory address".)
- rob74 2y ago
  Guru Meditation anyone? (https://en.wikipedia.org/wiki/Guru_Meditation https://en.wikipedia.org/wiki/Guru_Meditation)
- RandomThoughts3 2y ago
  Just stop writing memfault. I say it in jest but that's actually how I used to program a few years ago when I was working on large industrial pieces of software with long compilation time. You just have to be careful and check what you wrote before sending it to the machine. I think "iterative" programming has made people really complacent when it comes to silly errors. Slowing down can often do wonder.
  - ChrisRR 2y ago
    I feel like if you're writing C then writing with memory safety in mind should probably be autonomous anyway
simmonmt 2y ago
Forgive the dumb question... it's been ages since I've done Amiga programming in C. What behaves differently? Is the lower K of memory mapped, such that null pointer deferences cause excitement rather than simply crashing your program? Or is it something else?
- snvzz 2y ago
  I don't get it either, particularly as most advent challenges can be solved using just iso c and its standard library.
- arexxbifs 2y ago
  AmigaOS has no memory protection whatsoever. If your program crashes, so does the entire machine. And it will possibly bring your hard drive with it, too. Not unworkable, but not the most relaxed environment for fast’n’fun cowboy coding. You typically have to reboot a lot.
  - galangalalgol 2y ago
    I thought the Amiga 1k had page protection, just not virtual memory?
    - sagacity 2y ago
      No, there's no MMU.
      - badgersnake 2y ago
        Well, apparently if your CPU has one (030+) you can use something like Enforcer (http://www.sinz.org/Michael.Sinz/Enforcer/ http://www.sinz.org/Michael.Sinz/Enforcer/). I’ve yet to try it.
    - snvzz 2y ago
      No MMU. A1000 has... something. The WORM (write once read many), RAM used for the kickstart, which is latched as read-only after the kickstart has been loaded from floppy by the bootstrap ROM.
ChrisRR 2y ago
> I didn’t get very far, lack of memory protection makes things really hard What was the issue with lack of memory protection? If you're used to programming in C is there actually that much difference to running on a modern PC or embedded system?

peterashford 2y ago

Heh. Yeah, a memfault tanking the machine is not conducive to iterative programming :o)

lanstin 2y ago
Honestly, I forgot all about that aspect of ancient programming. It probably made one more careful, or more patient. (Source: typing 6502 programs into a hex "monitor" which is a way to edit memory, view memory, and issue "jump to this memory address".)
rob74 2y ago
Guru Meditation anyone? (https://en.wikipedia.org/wiki/Guru_Meditation https://en.wikipedia.org/wiki/Guru_Meditation)
RandomThoughts3 2y ago
Just stop writing memfault. I say it in jest but that's actually how I used to program a few years ago when I was working on large industrial pieces of software with long compilation time. You just have to be careful and check what you wrote before sending it to the machine. I think "iterative" programming has made people really complacent when it comes to silly errors. Slowing down can often do wonder.
- ChrisRR 2y ago
  I feel like if you're writing C then writing with memory safety in mind should probably be autonomous anyway

simmonmt 2y ago

Forgive the dumb question... it's been ages since I've done Amiga programming in C. What behaves differently? Is the lower K of memory mapped, such that null pointer deferences cause excitement rather than simply crashing your program? Or is it something else?

snvzz 2y ago
I don't get it either, particularly as most advent challenges can be solved using just iso c and its standard library.
arexxbifs 2y ago
AmigaOS has no memory protection whatsoever. If your program crashes, so does the entire machine. And it will possibly bring your hard drive with it, too. Not unworkable, but not the most relaxed environment for fast’n’fun cowboy coding. You typically have to reboot a lot.
- galangalalgol 2y ago
  I thought the Amiga 1k had page protection, just not virtual memory?
  - sagacity 2y ago
    No, there's no MMU.
    - badgersnake 2y ago
      Well, apparently if your CPU has one (030+) you can use something like Enforcer (http://www.sinz.org/Michael.Sinz/Enforcer/ http://www.sinz.org/Michael.Sinz/Enforcer/). I’ve yet to try it.
  - snvzz 2y ago
    No MMU. A1000 has... something. The WORM (write once read many), RAM used for the kickstart, which is latched as read-only after the kickstart has been loaded from floppy by the bootstrap ROM.

ChrisRR 2y ago

> I didn’t get very far, lack of memory protection makes things really hard What was the issue with lack of memory protection? If you're used to programming in C is there actually that much difference to running on a modern PC or embedded system?