QSIC update - v6 Unix boots and runs

[Noel Chiappa]

    > From: David Bridgham

    > today we booted v6 Unix successfully for the first time.

As in, the OS image was loaded from the SD card, then started up using only
the SD card for 'disk'. So this is a pretty major milestone. It's been a long
road (I just looked, and we started on this in the summer of 2015), but we're
finally getting there!

The Unix file system, including the OS and all the various bits and pieces
needed, like /bin/sh, etc, was prepared on a simulator (stock V6 won't run on
a /23, which has no switch register), and then loaded into the SD card using
'dd' running on a Linux box.

Our emulated RK11 doesn't do a perfect job of emulating an RK11 yet (e.g. for
some reason we haven't yet looked into, the BDV11 ROM code won't load the
bootstrap off the 'disk'; Dave had to manually load in an RK bootstrap using
ODT), but enough is now working to let Unix load and run.

    > Unix does use partial block reads and writes after all

For swapping, not for file-system I/O (which is all block-based).

    > We're getting close to the time when we need to think about making our
    > own circuit board rather than using the wire-wrap prototype we've been
    > having fun with so far.

At which point we'll be able to supply them to anyone who wants one...

It will be a while yet, but I think we are 'over the hump' on the project,
with the OS booting and running properly.

	Noel