MacOS supports pretty much any resolution as long as the pixel format on the Atari is the same as the Mac expects.EvilFranky wrote: ↑Mon Feb 14, 2022 7:27 pm This is really interesting!
So will it be possible to run this on a standard ST @ 8Mhz/4MB in mono? Will MacOS support 640*400 resolution?
Obviously not expecting games or any sort of audio, but messing around with the OS would be good.
(There is no emulation of graphics, MacOS is given a virtual display driver and from then on the Mac side will access the Atari screen directly as if it was native. This is one of the reasons why it can be so fast)
For most machines, that would be 640x400 mono.
Or a pretty nice 1280x960 MacOS desktop if you have a TT with mono monitor
Graphics cards work now too. Your milage will vary which modes are going to work, it depends on the card I suppose.
I have an ET4000 for PC in my Atari so the byte order is different from what Mac expects.
256 color & Mono modes works perfect but 15,16,24bit modes make wrong colors on my card.
I am not planning on doing anything to support a normal 68000 though. I think your best bet is to use the already existing Spectre-GCR. It's supposed to work quite well?
I am using CPU specific stuff to achieve virtualisation so at the moment it will only run on a 68030.
Supporting 68040/60 should be easy and only involve some MMU specific code. But since I don't have such machine I think adding that support would be up to someone else once this thing is on Github.
68020 with external MMU would be very extremely similar, if not the same, as the 68030 code but there isn't any such Atari out there as far as I know
I think getting it to run on a 68000 would not be for the faint of heart
This CPU really lacks support for any kind of virtualisation and it would become hard to prevent MacOS, or TOS, from regaining control and wreaking havoc on you virtual "hypervisor".
The 68010 is maybe slightly "easier", but still not nearly as easy as with the help of the MMU on 68020+.
Making sure MacOS is free to read/write to address range 0-0x2000 becomes a lot more challenging on these CPUs as well.
Not saying it cannot be done, I'm sure it can, but it won't be by me