3 ms·

He wasn't kidding when he said that the emulation is too slow to even properly register key presses in time. Booted in VirtualC64, tried to type in "dir", and i

by anyfoo 7y ago

He wasn't kidding when he said that the emulation is too slow to even properly register key presses in time. Booted in VirtualC64, tried to type in "dir", and it came out as "dr", and then took a pretty long time to tell me that "dr" isn't a thing. I then typed in "dir" slowly, and this time it worked, but took about a minute to type out the few directory lines... character by character. So, as the article suggests already, I'd really consider this to have been unusably slow even at that time. And then it suffers from the same problem as the actual Z80 CP/M cartridge, namely that the 1541 disk drive cannot read any disks that would contain CP/M stuff. But as a curiosity, that all makes this just more interesting.

teh_klev 7y ago
> Booted in VirtualC64 Perhaps and possibly an unfair comparison given that you're already running in an emulated C64?
- giovannibajo1 7y ago
  It would be worrying if a PC can’t emulate a C64 much faster than the original system. And if the GP didn’t remove frame locking, the emulator ran at the same speed of a real C64
- anyfoo 7y ago
  No, my computer, as most today, has plenty of power to emulate the C64 with cycle-accurate speed (at least close to), so it should be exactly the same performance as on a real C64. I even switched to unthrottled at times, which with my setup gives about what a ~9MHz C64 would be like. The real one is about 1MHz. Even that was very slow.
  - teh_klev 7y ago
    Fair enough, though I'd like to grab an actual C64 to see what the experience is really like with the C64's own hardware. But like all things here it's a hack, everyone's mileage may vary :)
    - anyfoo 7y ago
      Do you mean because of subjective feeling of it independent of speed? Because as for performance, we are talking about emulating a fixed-frequency machine thousands of times slower. There was no "variable performance", CPU and video timings are pretty much exactly defined. This CP/M emulator was exactly as fast or slow on any stock C64[1], and, correctness assumed, any emulator worth its salt on any non-ancient PC (20 years?) will show no perceptible difference. The "thousands of times slower" is not entirely true, since a C64 emulator has to emulate much more than just its CPU, and the emulator task gets uncontrollably preempted. But there is no way that CP/M will feel any different on the real machine, in terms of performance. [1] The only significant exception was that NTSC machines were a tiny bit faster than PAL machines: A tad over 1MHz vs. a tad below 1MHz, to fit the respective video standard's timings.

by anyfoo 7y ago

teh_klev 7y ago

> Booted in VirtualC64 Perhaps and possibly an unfair comparison given that you're already running in an emulated C64?

giovannibajo1 7y ago
It would be worrying if a PC can’t emulate a C64 much faster than the original system. And if the GP didn’t remove frame locking, the emulator ran at the same speed of a real C64
anyfoo 7y ago
No, my computer, as most today, has plenty of power to emulate the C64 with cycle-accurate speed (at least close to), so it should be exactly the same performance as on a real C64. I even switched to unthrottled at times, which with my setup gives about what a ~9MHz C64 would be like. The real one is about 1MHz. Even that was very slow.
- teh_klev 7y ago
  Fair enough, though I'd like to grab an actual C64 to see what the experience is really like with the C64's own hardware. But like all things here it's a hack, everyone's mileage may vary :)
  - anyfoo 7y ago
    Do you mean because of subjective feeling of it independent of speed? Because as for performance, we are talking about emulating a fixed-frequency machine thousands of times slower. There was no "variable performance", CPU and video timings are pretty much exactly defined. This CP/M emulator was exactly as fast or slow on any stock C64[1], and, correctness assumed, any emulator worth its salt on any non-ancient PC (20 years?) will show no perceptible difference. The "thousands of times slower" is not entirely true, since a C64 emulator has to emulate much more than just its CPU, and the emulator task gets uncontrollably preempted. But there is no way that CP/M will feel any different on the real machine, in terms of performance. [1] The only significant exception was that NTSC machines were a tiny bit faster than PAL machines: A tad over 1MHz vs. a tad below 1MHz, to fit the respective video standard's timings.