[lug] [Workshop] Building Your Own Linux Kernel

Jeffrey S. Haemer jeffrey.haemer at gmail.com
Sun Mar 8 07:55:35 MDT 2015

Sometimes, we didn't even have ones.

> Stop it! You're getting me hot! Separate I&D space FTW! ;)

The first micros to run Unix were Onyx boxes, built around a Z8000 chip
with little, Z80 I/O bottlenecks to talk to its 8 serial ports. They were
8-user, timesharing machines. There was a tape backup. Programs could
address up to 64K of memory.

The price? ~ $25K.

For those of you younger than Jed and Lori, a kilobyte is a micro-gig. The
Unix port was done by Interactive Systems Corporation (ISC).

When I started at the Estes Park office, in late 1983, ISC was finishing up
the first, commercial Unix port to an Intel box, IBM's PC/IX. PC/IX ran on
IBM's still-new PC/XT, which had a 5MHz, Intel 8088 (an 8086, but with an
8-bit data bus). If you splurged, you could add an optional, 8087 math
coprocessor to do floating point.

PC/IX could run with 128K of memory and the standard, XT, 10 Megabyte hard
disk, but was happier with a full 256K and an extra, 10M extension chassis.
Rob Kolstad's comment was, "You *can* run PC/IX with 128K. You *can*
bicycle to Alaska."

The extra chassis was the same size as the XT itself.

The price? $5K, plus another few $K for the expansion chassis, math
co-processor, extra memory, etc. Practically free. (If you wanted to be
really spendy, you could buy a CRT that would display color. Still,
practically free.)

You're yawning, waiting for the punchline. What's this have to do with
Lori's post?

One thing that made developers hot was that the XTs, unlike the Onyx boxes,
had separate instruction and data (I&D) space -- programs could address 64K
of code plus 64K of data -- so their Unix programs could be a *lot* bigger.

Jeffrey Haemer <jeffrey.haemer at gmail.com>
720-837-8908 [cell], http://seejeffrun.blogspot.com [blog],
http://www.youtube.com/user/goyishekop [vlog]
*פרייהייט? דאס איז יאַנג דינען וואָרט.*
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