Re: Minix 1.1 with QEMU

[Philippe Mathieu-Daudé]

Hi Will,

On 9/23/20 6:45 PM, Will Senn wrote:
> Long time user, first time poster :)
> 
> So, I'd like to be able to run Minix 1.1 on my Macbook Pro mid-2012
> w/16gb RAM (MacOS 10.14.6 Mojave). Qemu will run pretty ancient OS'es
> such as DOS 2.0, which I use all of the time. However, I'm having some
> difficulty getting Minix to run. I am able to boot the first floppy, but
> when I change to the second floppy, the system freezes and I can't tell
> what is going on. Here's what I did to get this far:
> 
> brew install qemu
> 
> qemu-system-i386 --version
> QEMU emulator version 5.1.0
> 
> mkdir ~/workspaces/retro-workspace/minix-1.1
> cd ~/workspaces/retro-workspace/minix-1.1
> aria2c
> http://download.minix3.org/previous-versions/bzipped/Intel-1.1.tar.bz2
> tar xvjf Intel-1.1.tar.bz2
> cp Intel-1.1/floppy_disk1 ./Disk01.img
> cp Intel-1.1/floppy_disk2 ./Disk02.img
> cp Intel-1.1/floppy_disk3 ./Disk03.img
> cp Intel-1.1/floppy_disk4 ./Disk04.img
> 
> 
> qemu-system-i386 -drive
> file=Disk01.img,format=raw,if=floppy,media=disk,readonly=off,index=0,snapshot=on
> \
>   -boot a \
>   -no-fd-bootchk \
>   -monitor telnet::2222,server,nowait -serial mon:stdio
> 
> Qemu boots to the Minix 1.1 Boot screen and says to swap to floppy 2, so
> in the monitor:
> change floppy0 Disk02.img raw
> 
> I press l (el) and it scans the disk, lists the files on the disk and
> reports no errors, but when I press =, it does a carriage return and
> just sits there. I'm pretty sure this is the Minix going bye bye and not
> necessarily QEMU, but I'm wondering if there is a way to see what QEMU
> thinks it is doing or if it is what's hung? Usually, at this point,
> Minix reads the disk contents into a Ramdisk and boots Minix.
> 
> Food for thought... Minix expects to run on an IBM PC (5150), IBM PC XT
> (5160), or compatible, and therefore the I/O is written for whatever
> floppy controller was extant at that time (I'm guessing here), so if
> that's different than modern day floppies, I suppose this could cause
> the problem I'm experiencing here. Is there a way to see the floppy
> controller activity in QEMU? Similarly, I gather it expects a CGA
> compatible monitor (EGA/VGA, etc should be fine).

Can you try adding '-machine isapc', which is closer to the 5150?

> 
> I appreciate your help on this.
> 
> Minix 1.1 works 'ok' in 86Box and other IBM PC emulations, so I know the
> floppies are fine.
> 
> Thanks!
> 
> Will
> 
> 
> 
> -- 
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