C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd)

[D. Hugh Redelmeier]

| From: Lennart Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org>

| On Mon, Aug 19, 2013 at 10:48:29PM -0400, D. Hugh Redelmeier wrote:
| > The 386 was introduced in 1985.  PCs using it came out in 1986.
| > 
| > OS/2 was first released in December 1987, but probably wasn't useful
| > (text mode only, ...).  Released a year later, 1.1 had a GUI.
| 
| Many voice mail systems and such ran on it.

In the era when the 286 was current?

Lots of big businesses built infrastructure based on OS/2 since they
were promised that it was the future.  IT departments fell for it.
Banks, ATM networks, Oil companies come to mind.

| > PC hardware was cutting edge because that was where the competition
| > was.
| 
| Well in many ways PC hardware was far from cutting edge.  It was just
| improving quickly in many ways.  It took many years for the PC to get
| anywhere near the hardware capabilities for sound and graphics that the
| Amiga or even most game consoles at the time had.

Right.  I should have qualified the statement somehow.  They innovated
quickly in things that they thought they could market in the short
term.

Long-term thinking was reserved for Microsoft, Intel, IBM and various
other companies that we've forgotten because it killed them.  That's
the way monopoly markets work.

It took years before the PC market valued multitasking.  Remember the
horror of TSRs?

The PC market was very conservative of interfaces.  Remember the A20
fudge?  Example: because it was thought that vast amounts of PC
software depended on the 8086's wrapping of addresses at 1MiB,
chips/systems well into the Pentium era could be set to wrap there.
As far as I know, there was very little software that actually broke
without this feature.  A lot of systems broke due to this feature
(i.e. matching A20 handlers with your hardware was non-trivial).

| > - UNIX clones: Coherent, Whitesmith's Idris, Minix, and others I've forgotten
| 
| Did SCO or unixware ever qualify as good options?

Yes, especially considering MSDOS or OS/2 as the alternatives.

They were good, just not to our taste.

| > - BeOS
| 
| That was never a reasonable choice for anything.  Designing a new OS
| without multiuser or security taken into consideation at all was just
| amazingly stupid.

That one lack doesn't veto it.  Remember that the dominant alternative
had that limitation too.

| > - modern UNIXes: *BSD, Linux, OSX, Solaris
| 
| I have dealt with Solaris x86, and it wasn't pleasant.

Why?

Lack of familiarity with the SVr5-ness of it?  I'm OK with that.  BSD
has its own flaws.

Lack of drivers for your hardware?  All alternative OSes have that
mountain to climb.

| Hmm, the Ontario goverment 'Icon' systems ended up picking the 80186,
| and they were not intended to be PC compatible.  Not an 8086 or 8088,
| but related.

Right.  That was a bit of a government boondogle.  I don't know how
the processor was chosen.  QNX ran on PC hardware initially, so maybe
that was the deciding factory.  I think that they used the Watcom C
compiler, also targetted at the PC.

| > | I have written MMU code for the 386.  What a mess.
| > 
| > In what way?
| 
| 16 bits of the address go in one part of the data structure, the
| next 8 bit somewhere else, and the last 8 bits in yet another place.
| Very obvious that every time they extended the address range, they threw
| it at the end and didn't ever think that maybe we will need to do this
| again so we should reserve room for the future.  The x86 is just garbage
| design pilled on top of garbage design for decades.  I haven't dared
| look where the new 32bit for amd64 ended up.

I guess you are referring to the segment descriptors and gate
descriptor.  Here's an (unreferenced) wikimedia diagram
<https://commons.wikimedia.org/wiki/File:SegmentDescriptor.svg>.  The
parts in italic were added by the 386, and yes, the result isn't
contiguous.  This is just annoying, not a serious problem.  That's
kind of how things evolve: not for beauty but for function.

| Whenever intel decides to thrown away the old and do something better,
| they end up creating something even more awful (like the Itanium).

The Itanium was a noble experiment.  It's just that (a) they didn't
realize it was an experiment, and (b) they poured their resources into
the x86 battle, starving the Itanium project, and (c) they took the
wind out of the sails (sales?) of RISC processors.
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