Amiga Tools 3/Amiga Tools 3.iso/demo/fun/mags/mb-oct95/docs/mb_48.txt

Text File | 1995-09-30 | 19.5 KB | 369 lines

                          Andy's Opinion: PC's
                          ====================

Have you overheard this conversation before:

PC owner:    "Your Amiga is shite!"
Miggy owner: "Yeah, well your PC can't even multitask!"
PC owner:    "Oh yeah? Never heard of Windows '95?!"
Miggy owner: "Ha! That crap! It needs 8 megs just to get out of bed!"
Mac owner:   "..my quadra can mutlitask..."
PC & Miggy owners : "SHUTUP!"

Hmm,  lots  of  fun  I'm  sure.   This sort of rubbish doesn't get anyone
anywhere  though.   The  problem  is  that  computer  users  are  usually
isolated:   PC  users think of Amigas as games machines, Amiga users take
one  look at DOS or Windows and laugh and Mac users, well I doubt they've
got a Mac to play games!

I  have  over the years, being a complete techno-addict, attempted to use
any  computer  I've come across.  Although old '80s computers were fun in
there day I don't thing you need any more nostalgia inducing articles!

Anyway  of more interest is my experience programming Macs at university,
Windows  programming  and my current quest to figure out Intuition on the
Amiga.   More and more people are using computers and the problem is that
they  most  only  see  the  exterior,  i.e.   type  things  in, run a few
applications,  games,  etc.  The interior workings and the history of the
computer they use is hidden to them.  These points may not seem important
as  obviously,  when  you  get  right  down to it, it's the software that
matters.   However,  the  software, current hardware and the whole "feel"
about  a  specific computer is dictated by how the hardware has developed
over the years.

Okay,  down  to  the fundamentals.  This article will only refer to Macs,
PCs  and  Amigas,  as I feel these are the only current computers the Joe
Public  may come in contact with.  I don't really see any chance of Atari
ST  owners  reading  this  so  lets  slag 'em off now:  no way can anyone
convince me the ST is a "current" machine.  Even the Amiga is technically
obsolete until ESCOM start selling them!

Everything  in  a  machine  is important (32 megs of RAM won't do you any
good on a 386SX running in EGA) so here is the nitty-gritty:

PCs
---
IBM  PC Compatibles were first developed by IBM in the late '70s based on
the  16-bit  8086  CPU  from  Intel.   Note  that  the  8086 works 16-bit
internally  and  externally  meaning it mainly deals directly with 16-bit
numbers  (this  will be more relevant when you read about the 68000).  At
the   time   home   computers   were  dinosaurs  and  the  PC  was  quite
revolutionary.  Most hardware functions were carried out by cards plugged
into the machine meaning easy upgradability.  Also IBM had an open policy
about  the  design  meaning  anyone  could manufacture a PC or a hardware
add-on based on IBM's machine.  This, coupled with the need for computers
in  America  to  do  tax-returns  (no  P.A.Y.E.!) meant the PC as a small
home/business computer became very popular.

Wow,  great  start,  eh?  The first IBM machines came with 16k-64k of RAM
(that's  right:   kilobytes!).   Unfortunately, the original designers of
the  BIOS, the start-up program in ROM, thought that no-one would need to
access more than 1 megabyte even though the 8086 could easily handle more
(remember:   1MB  =  16 x 64k, this sounded like a lot in the '70s!).  As
the  machine  became  more  popular  in  the  early  '80s  more  and more
applications  reached  the  so-called  640k  barrier  (the other 384k was
allocated  to the ROMS, input/output and extra hardware).  Also the 8086,
due  to  internal  design,  only  liked  to  handle memory in 64k chunks.
Programmers  would  have  to  carefully  write  their  applications to be
divided  into  64k code and data modules as addressing outside a specific
chunk meant a different and slower set of machine code instructions.

In  the  mid  '80s  the  286  machines arrived, hoping to solve all these
problems.   Based  on the 80286, these machines could access more memory,
had  faster processor speeds and had upgraded card slots to plug in extra
hardware.   Unfortunately  this machine had to be compatible with the old
8086  machines  and  programmers  rarely  bothered  to write 286 specific
programmes.   (Note that Windows 2 wasn't as big as it's older brother at
this  time.)  No-one  managed  to  get  support  for an upgraded BIOS and
Microsoft,  who  wrote MS-DOS didn't bother with directly supporting more
memory as there were still plenty of old 8086 computer users who wouldn't
be able to use such improved features.

The  PCs of these times were fairly average business computers.  The best
you  would find might have EGA colour display (hires, 64 colour palette),
640k of memory and a 40MB hard drive.  Note that even as the Atari ST and
the  Commodore  Amiga  were  appearing,  PC users had already given up on
floppy  disks  for  serious  work  even  though  hard  drives were fairly
expensive.  Few software companies bothered about extra memory, only real
heavy-  weights  like  Lotus  developed  it  for their programmes.  Lotus
1-2-3,  still  hot  today, was THE top program at the time - remember the
Americans and their tax returns.

After  the  286  came a turning point.  IBM and Microsoft were developing
ideas to solve the now serious limitations when they had a tiff and broke
up  their  partnership  (can't  remember  the reasons now.  Two solutions
appeared as the latest CPU arrived:  the 80386.

Now,  the  80386  was/is  (some people still use then ;-) a proper 32-bit
CPU,  a  leap in power over the 8086 and 80286.  It still had a fall-back
mode  to  run  the  old  software  but it could do simple multitasking by
emulating multiple 8086s.  This had to be exploited.

IBM's  solution  was  radical.   It  redesign the PC and gave it a proper
32-bit  operating  system:  PS/2 and OS/2 were born...  and died not long
after.   Unfortunately,  due to IBM's open policy on design - a good idea
to boost the machine when it first came out - meant that everyone and his
uncle  were  making  PCs!  Thinking that they'd loose out if anyone could
make  a PS/2 machine, IBM had no open policy this time so other PC makers
just   incorporated   the  new  80386  technology  into  the  old  design
specification.  Now IBM were selling a new, highly expensive machine that
ran  a  new  operating  system.   OS/2  programmes didn't run on standard
machines  so  little PS/2 specific software appeared.  Obviously the idea
was doomed.  Joe Public went and bought cheaper PCs running the other new
operating  system  appearing:   Windows  3.  IBM lost a lot of money with
this  failure  and  their  mainframe  business  was  also losing money as
offices bought loads of cheap PCs instead of one mainframe computer!  IBM
had sown the seeds of their own destruction!  (Har, har <EVIL GRIN>)

Microsoft's Windows 3.0 would run on the cheap PCs and gradually, ever so
slowly,  Windows programmes took over from DOS.  Microsoft's advantage at
the  time  was not having to make, design and support hardware, like IBM.
It  just  had to look at what people had and write programmes for Windows
even  if  no-one  else  wanted  to.  Word, Works, C and BASIC all had DOS
versions  (can't see anyone using them now :-) so Microsoft had plenty to
base their Windows specific programmes on.

The  VGA  graphics  standard came out in the late '80s and partly started
the rise in decent PC games (hey, 640 x 480, 256 colours is fine).  Sound
and  joystick cards came out and with very large hard drives as standard,
PC  games  were  the  first  epics.   Classics such as Wing Commander and
Ultima set the trend for eating up disk space and memory.

So, finally we have the current machines:  486s and Pentiums with diverse
forms of graphics cards based loosely on the original VGA standard and CD
drives  are  very  common.   £800 gets a decent machine these days:  good
machine for games, excellent for business.  What's the down side?

Well,  no  one has complete control over the PC market.  This is good for
prices - lots of competition - but bad for overall development.  Consider
the  standard  ports, the serial and parallel ports haven't changed since
the  '70s!!!  The mouse and keyboard connectors are ideas nicked from the
defunct  PS/2.   The  IBM  PC  standard  has  suppressed  (yes!   I  said
suppressed  all you paranoid X-files fans ;-) intelligent hardware design
unless  it  was  absolutely necessary.  Imagine a PC that could fine tune
the monitor from Windows as standard, you could pay thousands for this at
the moment.  Consider a printer that could specifically tell Word that it
couldn't  print  because  it was off-line or out of paper - not some duff
Retry/Cancel  requester  saying bugger all.  These features are available
(see the Mac section) but no-one will put in the effort (money) as profit
margins  are  so tight in the PC industry.  Big players such as Microsoft
and  Intel,  can  only influence PCs.  Hopefully Windows'95 and "plug and
play" with start a trend to better design.  Hey, PC owners!  Do you still
get games asking what sort of sound card you've got?  They should be able
to find out!

Another  consequence  of  lack  of  control is limitations.  PCs are only
limited  by  time.   Every  year,  or  month,  faster  PCs appear, better
graphics  cards,  larger  hard  drives  etc.   With  little to stop them,
programmers  can  write  applications that demand 8MB memory & 100MB disk
space  rather  than  write  efficient  code  for  a  2MB,  80386 machine.
Microsoft  is partly to blame for this as Windows is terribly inefficient
in  its internal operations leading naturally to inefficient applications
-  it  all  seems to have got worse with Windows'95 as that must have 8MB
memory to run.

Ha!   If  Microsoft  want  to  do  me  for  libel  let  them consider the
"inferior"  Workbench of the Amiga and can they make a program with a few
buttons to do a few simple disk functions in less than 10k?  In fact, can
you write ANY Windows programmes in less than 10k?!

Um,  sorry if that seems like a bit of bias creeping in but I spent eight
months  doing  Windows programming.  Visual C/C++ then was on 20 odd high
density disks and we needed a new set of shelves for all the manuals.  If
you  ever  try programming for Windows you WILL believe Microsoft have an
executive  lift  down to Hell!  (That's where they get their design ideas
;-)  (Hehe,  note  to  PC  peeps:   I haven't even brought up the Windows
16-bit  /  32-bit cockups by Microsoft, words like "thunking" will really
confuse people :-/

So,  my  final  opinion  of  the PC is of a high spec machine with little
direction  as  far  as  hardware  development,  with  software indirectly
controlled  by  Microsoft  who's  programmes are great on the surface but
big,  clumsy and inefficient inside.  Wow, bit like a description of most
Western countries :-D

Quick PC Glossary & Notes
=========================

8088  -  spotty  younger  brother  of  the  8086:  8-bit external, 16-bit
internal

IBM PC - the original 16k 8086 machine

IBM XT - more common 8088 that most people see as the first PC

IBM AT - 80286 machine

IBM PS/2 - the wunderkinder ( NOT!)

IBM PS/1 - name for original design PCs (not PS/2)

OS/2 Warp - salvage attempt by IBM of the original OS/2, this runs on
   (supposedly)  any  PC,  multitasks  and  will beat Windows'95...  some
hope!

Windows 3.0 - the original

Windows 3.1 - bug fixed version ;-)

Windows for Workgroups - Windows 3.11, proper network support

Windows  NT  -  shit  hot  (but  highly expensive) multitasking operating
system
   mainly for heavy duty file servers (even supported multiple CPUs!)

WIN16 - programming term used for standard (16-bit) Windows applications

WIN32 - Windows NT (32-bit) applications

WIN32s - WIN32 subset:  weird Microsoft system whereby you could write
   32-bit programmes for Windows 3.1 but they weren't fully compatible
   with Windows NT (Bill Gates, don't you just luv 'im :-D

Thunking - you really want to know?  Okay you maniacs!  This is a method
   of getting 32-bit systems to "think-down" to the level of 16-bit
   systems.  Um, can't explain it any better without another 10 pages!

Motorola
========
This is a separate section for the 68000 CPU as it is common to the Amiga
and  Mac  (even  the Atari ST).  The advantages of this CPU are common to
all machines.

In  the late '70s Intel, Motorola and Zilog (the Z80, remember?) were all
rushing to make a 16-bit CPU.  Zilog got nowhere with their Z8000 as they
didn't manage to sell it to any really big names.  Intel rushed out their
8086  and  it  got snapped up by IBM.  Motorola waited a while...  At the
time,  these companies knew that the best technology available could only
manage  to  make  a  16-bit  CPU  cost  effectively.   As mentioned in PC
section,  the 8086 was 16-bit internally and externally.  The later 68000
from  Motorola  was  still  16-bit  externally  but  inside  it worked at
32-bits.   Programmers could write routines to add bigger numbers in less
code  -  not a really big advantage.  However, when the 68020 came out it
was  fully 32-bit and yet could still run 68000 programmes perfectly.  No
fallback  mode  as  for the 8086.  Also the 68000 series of CPU never had
the  same  serious problem of working with 64k chunks as the 8086.  (Code
is  still quicker using small relative jumps on the 68000 but these jumps
can cross the "boundary" that exists between 64k chunks on the 8086.)

The  average  user  couldn't  care  less  about  bits and chunks but to a
programmer  it  means the 68000 is easier to program and although you can
write  68020 specific code, the differences aren't as radical as those of
the  8086  and  the 80386.  All this affects efficiency of an application
and maybe the sort of people who program the machines.

Apple Macs
==========
Alot more happened in the '70s than the average user would credit.  Xerox
(yes,  the photocopier people :-) were working on a standard visual style
for  hires displays called X-Windows.  You may have occasionally heard of
this,  X-Windows is basically a definition of the features and appearance
of  any  visual  operating  system  employed  on  a  computer.  Microsoft
mentioned X-Windows in connection with Windows but really the standard is
only  mentioned  in  relation  with  Unix  machines like Sun Workstations
(University students can check this out :-).

Apple,  who  like Commodore had made a success with 8-bit home computers,
based their Apple Macintosh series on the X-Windows standard.  Unlike the
development  of  the  PC, Apple held on very tightly to their designs and
took  lots  of  people  to court over "look & feel" over the past decade.
The  Mac  is  centred  around  the  operating system, called System!  :-D
Although  the specs of machines have changed over the years, all versions
of  System  have basically stayed the same as far as central features and
operations.   The  greatest  change  was  probably  the move from mono to
colour displays, although serious Mac gurus will no doubt point out other
key changes :-)

Over  the years, Apple have gradually added more and more streamlined and
Mac  specific  features.   The  early  Mac  512k & Mac Plus machines were
fairly  simple  machines but the addition of special hardware such as the
Apple  bus  for  input  devices  (mentioned earlier) meant the machine is
definitely one for the serious professional type.

So,  the  Mac has had tight development, progressive hardware, consistent
software, what's the down side?  Well unfortunately the machine maybe too
tightly  held by Apple.  The System software is totally restricted to the
graphic  interface  and  fairly  complicated  to  program properly.  This
restricts  the  chance  of users getting the programming bug and having a
go.   No  chance  of  writing  a  quick  CLI  or MS-Dos command :-( Also,
hardware extras are fairly specific to the Mac and common PC parts rarely
work without some adaption.

All  this  has  contributed to the Macs high level professional usage but
restricted its widespread appeal.

Amigas
======
Well,  I  don't  know  whether  to  bother writing anything!  Most likely
you've already got one and think it's shit-hot B-D

Alright,  I'll just pick out the important information in relation to the
previous machines.

The machine was initially developed by a load of wacky designers based in
California.   Commodore  snapped up their company from under Atari's nose
when they spotted the potential of the machine.  Unfortunately unlike the
great  engineers,  full  of  neat  ideas,  the Commodore management never
really understood the machine, as we all know :-(

Anyway, the key hardware that makes the machine so special is absent from
the  PC  and Mac.  Although released with a fairly powerful 68000 running
at  under 8MHz the real power comes from the custom chips, one area where
Commodore's   engineers   always  excelled.   The  Blitter  and  graphics
co-processor  (the  Copper)  mean  that screen handling and updating need
little  processor  work.  This is unlike the PC and the Mac where (unless
you have lots of money) the CPU does all the work of shifting shit around
the  screen,  time  that  could  be used on running your programmes!  The
Amiga  also  has  Direct Memory Access hardware (DMAs) where hardware can
access  memory  without  processor  intervention.   This means the floppy
drive can load data without stoping other hardware.

I  think you can see where this is leading...  the multitasking software!
As  the  internal  and  external  hardware can operate independently this
forms  the  perfect  base for multitasking operations.  In fact, when the
hardware  was  finished the designers just ported a small version of Unix
(called  TriOs) as they couldn't be bothered to write their own O/S!  The
Intuition  based  on  the  multitasking  O/S  is  a  fair rip off Mac and
X-Window ideas.  We're lucky the Amiga turned out as well as it did!

There  is one other key feature the Amiga had in its initial development:
the  Commodore 64!  Eh, wot am I on?  No wait, the early '80 saw the rise
of  the 8-bit machines and the mid '80s saw the handover to 16-bits.  The
Amiga (and even the Atari ST) gained users from upgrading 8-bit owners to
a much greater extent than the PC or Mac.  This user base has "flavoured"
the  machine  to the same extent as the high spending business users have
affected the Mac and PC.

The  Amiga  has always multitasked well and the graphics are now only out
of  date  due  to the lack of development due to the Grand Commodore Cock
Up.   One  feature  the  Amiga  misses  on  is  Planar  versus Bit-Mapped
graphics.   Planar  graphics  mean that one byte in memory represents one
pixel  on screen.  Bit-mapped graphics mean one bit in memory affects one
pixel  on  screen,  several  bit-maps  are needed to describe multicolour
displays.   Without getting too technical planar graphics are well suited
to  the  flash  3-d  and texture mapping seen in PC games whereas bit-map
graphics  are better for 2-d displays:  platform games, shoot 'em ups and
beat 'em ups.

Tech  heads  may  already  know  that  the  CD32  has  a planar-to-bitmap
converter   in  hardware  (or  chunky-to-bitmap,  as  it's  also  known),
hopefully  planar  graphics  will  become  standard  if ESCOM get down to
serious  hardware development thus meaning serious DOOM games :-D (Fears,
Gloom  etc all use some crafty coding of the custom chips but only manage
very low res display :-(

And Finally
===========
Some  ideas to think about I hope!  The main thing to realise is that the
PC,  Mac  and Amiga have had different origins, different development and
have  different  user  bases.   Arguing relative merits of these machines
will stop when hell freezes over.

Ease up and chill out!

Andy Pandy

END
===