Comments for Virtually Fun

Comment on AIX 4.1.5 on QEMU by tenox

tenox — Mon, 02 Nov 2026 12:26:14 +0000

In reply to nop.nz. Yeah it frustrates me too. I'm going to get it fixed. Thanks for the gist it helped! I'll post an update!

Comment on Windows NT demo on the DECstation 5000 by tenox

tenox — Sun, 01 Nov 2026 07:40:30 +0000

In reply to neozeed. it's coming!

Comment on My favourite PowerMac is a Nintendo Wii by Stephen Ferrell

Stephen Ferrell — Sat, 31 Oct 2026 06:27:04 +0000

I can see some Amiga OS4 fanatics asking you to do a Wii port.

Comment on AIX 4.1.5 on QEMU by nop.nz

nop.nz — Fri, 30 Oct 2026 22:59:03 +0000

I don’t know if it bugs anyone else, but for me the biggest frustration I had with AIX on QEMU was that it didn’t support any form of idle, and I’m not a huge fan of leaving an emulator to chew up an entire CPU core the whole time it’s running. I wrote a quick and dirty patch to get idle working on AIX 4.3.3 and have had that running for some months without noticeable issue, and it looks like it works (with a bit of tweaking) on this system too. I figure it might be handy, so here it is.

You will need to rebuild QEMU to tell it to check for idle on the 604 processor (as the real one didn’t actually support idling I don’t think…), and then patch the kernel. I’ve only tried this with the uniprocessor kernel; I suspect it wouldn’t work with the multiprocessor one, at least not without a bit of tweaking.

The QEMU patch is just changing “pcc->check_pow = check_pow_nocheck;” to “pcc->check_pow = check_pow_hid0;” in target/ppc/cpu_init.c. And the kernel can be patched with the below commands from within AIX:
# cd /usr/lib/boot
# cp unix_up unix_up.bkp
# printf ‘\174\020\372\246\144\000\000\200\174\020\373\246\174\000\000\246\144\000\000\004\174\000\004\254\174\000\001\044\114\000\001\054\110\001\116\006’ | dd of=unix_up obs=1 seek=21960 conv=notrunc
# printf ‘\100\236\124\002’ | dd of=unix_up obs=1 seek=86036 conv=notrunc
# bosboot -a

Then reboot, and if it all went OK, the CPU usage should be much reduced.

Some disparate notes on the process are here which explain the logic a bit more: https://gist.github.com/0x90nz/64accadfcda766637b731e4f3323f470

Comment on My favourite PowerMac is a Nintendo Wii by tenox

tenox — Fri, 30 Oct 2026 07:00:19 +0000

Can you run Tenon Power MachTen on it?

Comment on OS/2 PowerPC Edition on QEMU by xyanide

xyanide — Tue, 20 Oct 2026 17:56:40 +0000

Awesome stuff!
I wonder if we will see proper AIX emulation soon?

Comment on OS/2 PowerPC Edition on QEMU by Brian Ledbetter

Brian Ledbetter — Tue, 20 Oct 2026 11:05:24 +0000

Amazing!!!!!!!!!!!!

Comment on Windows NT 4.0 PowerPC on QEMU by tenox

tenox — Tue, 20 Oct 2026 03:07:18 +0000

In reply to Brian Ledbetter. yes, going to post tonight

Comment on Windows NT 4.0 PowerPC on QEMU by tenox

tenox — Tue, 20 Oct 2026 03:07:06 +0000

In reply to bert64. yes it is, next blog post coming up tonight

Comment on Windows NT 4.0 PowerPC on QEMU by Brian Ledbetter

Brian Ledbetter — Mon, 19 Oct 2026 13:17:20 +0000

In reply to Brian Ledbetter.

bootable CD not bootable without reinstalling via a system services floppy… And it’s been 35 years since I touched an Alpha system that would even remotely be comparable to this lol

I’ll wait for the experts, I reckon!