5 ms·

Classic Mac OS all the way up through OS 9 handles 1-bit and grayscale displays quite well. I’ve thought for some time now that if one were build a System 7.5/

Classic Mac OS all the way up through OS 9 handles 1-bit and grayscale displays quite well. I’ve thought for some time now that if one were build a System 7.5/Mac OS 8 laptop with an e-ink or high quality transflective display (like that found on the Playdate[0]) and new 68k/PPC SoC built on a modern node with a modern battery, the resulting device would be surprisingly useful even if lacked connectivity. It’d sip power, with battery life likely measured in weeks or months and could probably be kept charged with a lid-sized solar panel. [0]: https://play.date/ https://play.date/

Someone 3y ago
> It’d sip power Are you sure? I think Classic MacOS effectively always busy-looped (WaitNextEvent would block, but only if the OS could run another event loop), never sleeping its (single) CPU. https://developer.apple.com/library/archive/documentation/mac/pdf/MacintoshToolboxEssentials.pdf#page52 https://developer.apple.com/library/archive/documentation/ma...: “The Event Manager reports a null event when your application requests an event and your application’s event stream does not contain any of the requested event types” If that’s true, that modern node CPU would not sleep most of the time, but just loop a lot faster.
- wk_end 3y ago
  Would a 68k on a modern node running at a fraction of its potential max speed burn through very much power? Apple managed to get multiple hours of battery life out of 68k chips on classic MacOS PowerBooks...
- nxobject 3y ago
  Would it be any different than, say, battery-powered portables like the TRS-80 Model 100?
  - eichin 3y ago
    As described at the time, the contemporary Sinclair Z88 had a separate bit of management logic that kept the Z80 CPU asleep until there was some interaction, in order to get ludicrous runtimes on 4xAA. (I wouldn't be surprised if the Model 100 did similarly, but there was no point in doing it on machines that plugged into the wall...)
    - hedgehog 3y ago
      You could do this to an emulated 68k Mac as well, software written after the PowerBooks shipped should all be ok with being held in sleep most of the time. A few things would need hacks like cursor blink (don't do it) and updating displays like clocks (wake every minute?). Interesting.
- DerekL 3y ago
  Note that that function has a sleep parameter. It doesn't return until an event has arrived or the sleep time has elapsed.
  - Someone 3y ago
    I may be mistaken, but I don’t think Apple ever stopped the CPU (a 68000 could be stopped and continue running on an interrupt, but I don’t think they ever used that)
    - DerekL 3y ago
      Yeah, it might not have saved power, but it did allow the machine to spend time on useful things.
- morsch 3y ago
  So the CPU on a PowerBook never went into a low power state? The maximum power draw of a 68020 apparently was 1.75W, so I guess it's possible.
  - Someone 3y ago
    Does the 68020 even have low power states? I couldn’t find a definitive answer, but did find https://www.manualslib.com/download/1342088/Motorola-Mc68020.html https://www.manualslib.com/download/1342088/Motorola-Mc68020... and https://www.nxp.com/docs/en/data-sheet/MC68020UM.pdf https://www.nxp.com/docs/en/data-sheet/MC68020UM.pdf, which dont’t seem to mention them.
footlose_3815 3y ago
I have 9.2.2 on an old imac with an SSD on it, it’s lovely.

Someone 3y ago

> It’d sip power Are you sure? I think Classic MacOS effectively always busy-looped (WaitNextEvent would block, but only if the OS could run another event loop), never sleeping its (single) CPU. https://developer.apple.com/library/archive/documentation/mac/pdf/MacintoshToolboxEssentials.pdf#page52 https://developer.apple.com/library/archive/documentation/ma...: “The Event Manager reports a null event when your application requests an event and your application’s event stream does not contain any of the requested event types” If that’s true, that modern node CPU would not sleep most of the time, but just loop a lot faster.

wk_end 3y ago
Would a 68k on a modern node running at a fraction of its potential max speed burn through very much power? Apple managed to get multiple hours of battery life out of 68k chips on classic MacOS PowerBooks...
nxobject 3y ago
Would it be any different than, say, battery-powered portables like the TRS-80 Model 100?
- eichin 3y ago
  As described at the time, the contemporary Sinclair Z88 had a separate bit of management logic that kept the Z80 CPU asleep until there was some interaction, in order to get ludicrous runtimes on 4xAA. (I wouldn't be surprised if the Model 100 did similarly, but there was no point in doing it on machines that plugged into the wall...)
  - hedgehog 3y ago
    You could do this to an emulated 68k Mac as well, software written after the PowerBooks shipped should all be ok with being held in sleep most of the time. A few things would need hacks like cursor blink (don't do it) and updating displays like clocks (wake every minute?). Interesting.
DerekL 3y ago
Note that that function has a sleep parameter. It doesn't return until an event has arrived or the sleep time has elapsed.
- Someone 3y ago
  I may be mistaken, but I don’t think Apple ever stopped the CPU (a 68000 could be stopped and continue running on an interrupt, but I don’t think they ever used that)
  - DerekL 3y ago
    Yeah, it might not have saved power, but it did allow the machine to spend time on useful things.
morsch 3y ago
So the CPU on a PowerBook never went into a low power state? The maximum power draw of a 68020 apparently was 1.75W, so I guess it's possible.
- Someone 3y ago
  Does the 68020 even have low power states? I couldn’t find a definitive answer, but did find https://www.manualslib.com/download/1342088/Motorola-Mc68020.html https://www.manualslib.com/download/1342088/Motorola-Mc68020... and https://www.nxp.com/docs/en/data-sheet/MC68020UM.pdf https://www.nxp.com/docs/en/data-sheet/MC68020UM.pdf, which dont’t seem to mention them.

footlose_3815 3y ago

I have 9.2.2 on an old imac with an SSD on it, it’s lovely.