Experimental Micro Channel Support In NetBSD

Looking for something to do with that old PS/2 in the cupboard? NetBSD can now be booted on it. Support is strictly experimental at the moment, and available as a patchset to the main code.

Comments

Re:Whoo-Hoo!

[Guy Harris]

Next, an AS/400 uses a memory model that is partly enforced by hardware, creating a control memory and a main memory. The software in the control memory (part of which can be swapped to main memory in some cases) provides an interface to applications and services that is very simular to a virtual machine. Because this is more or less enforced in hardware, there is no easy escape to facilitate a Unix style setup on this kind of machine

The virtual machine interface is, at least as I read what one of the architects (Frank Soltis) of S/38 and AS/400 said in his book Inside the AS/400, implemented largely by binary-to-binary translation; compilers generate MI code, in a very high-level instruction set, and code in the OS kernel translates it to machine code (the 3x0-ish IMPI on the CISC machines, extended PowerPC on the RISC machines) the first time it's run.

Whether this makes it possible to run OSes other than the "licensed internal code" (OS kernel) and OS/400 is another matter (although I have the impression that the "RS64" 64-bit PowerPC chip in some RS/6000's is one of the chips done for the AS/400, and just runs with tag bits turned off, so maybe it's possible).

Re:Whoo-Hoo!

[Ed Avis]

Linux support for MCA bus machines has been around for _years_ and is stable and reliable. It's just that it only recently got into the main kernel tree. But now you can build your 2.2 kernel with MCA support and it Just Works. A lot of the MCA hardware such as ESDI, SCSI, XGA and network cards is supported too.

AFAIK FreeBSD also has working MCA support. It's good to see NetBSD getting it too - at about the same time as it's being dropped from Windows NT. (Win2k doesn't support MCA bus machines.)

If you have a PS/2 lying around in the cupboard, you have no excuse for not sticking Slackware on it right away. Also I'd like to insert a plug here for the newsgroup comp.sys.ibm.ps2.hardware, which is cool.