[djweis]

The book you are looking for is https://www.amazon.com/RISC-System-6000-PowerPC-Architecture...

It explains the architecture of the 7011/250 in detail. When I was much younger I was working with a group to get Linux on there. We got to the point of making a boot floppy that would display a 3 digit number on the front panel.

[kev009]

http://ps-2.kev009.com/rs6000/rs6000-netbsd.html

[djweis]

Are you still actively working on the port?

[kev009]

I'll get back to it eventually, I have 8 7011s with the intention of circularly netbooting them to rapidly test kernel builds. Also have a bunch of others (several of each 7006, 7009, 7012, 7013 and then the newer prep, chrp, P4/5/6/7/8/9). Most my free time is spent working on FreeBSD networking right now.

[djweis]

If you would ever part with a 7011 I'd happily pay for it plus shipping.

[kev009]

Set up an eBay saved search, they are the most common of the MCA RS/6000s to show up. Price target $150-200. If that doesn't work out in a reasonable timeframe (say 1 year) contact me.. otherwise better to rescue from the market than other collectors, dollar for dollar, to keep more machines out of the landfill.

There is a 220, which have the interesting RSC chip (good for AIX 3.2.5, probably not a good target for anything else including NetBSD due to specialized CPU support that would be necessary): https://www.ebay.com/itm/335464230008

You'd want a [250,25T,25W] (66 or 80mhz, hard to determine which without seeing the planar) for NetBSD or AIX up to 4.3.3 (5.1 will run but is a little heavy for the hardware).

There is a now rare 7248, this is a second gen prep system that is special because it can boot Solaris, OS/2, NT, AIX, NetBSD. It looks similar to the more ubiquitous 7043-140 which is also a good machine but can't do all those OSes. Price is close to reasonable for what it is: https://www.ebay.com/itm/186792645248