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* Re: Port I/O
@ 1996-11-13  0:00 Simon Johnston
  1996-11-14  0:00 ` Michael F Brenner
  0 siblings, 1 reply; 15+ messages in thread
From: Simon Johnston @ 1996-11-13  0:00 UTC (permalink / raw)



I think the comments on NT are a little unfair, we are using it in a =
high-speed near real-time mission critical environment (150+ lane =
hypermarkets) where throughput is very much dependant on O/S =
performance. In this environment we have had to develop our own NT =
drivers for some hardware and make use of a number of other facilities, =
we also have a good relationship with the NT guys in Redmond.
As far as the game SDK is concerned I again question the comment on =
price, I got two copies free with our MSDN subscription (if your =
developing MS based software without MSDN you deserve everything you =
don't get!) and I'm sure if you talk nicely to MS they can get you a =
copy. With the game SDK Windows 95 and Windows NT have full DirectX, =
DirectSound, DirectDraw, DirectPlay etc. which do provide port level =
access to the hardware, fast enough for game programming.=20
As far as industrial control is concerned then I think you should be =
talking directly with Redmond as there is quite a push to get NT into =
this area.

Michael F Brenner wrote:
> Ed Falis of Thomson Software Products 617 221-7341 said:
>  > you might ask yourself
>  > why you're trying to do what you're doing (presumably direct =
hardware
>  > manipulation) from user code under NT or W95 rather than going =
through
>  > a device driver.
>=20
> The obvious answer is that NT does not provide device drivers, or
> fast enough device drivers to do the kind of animation, serial =
control,
> parallel control, disk access, and sound that the games, simulatons, =
and
> robots we are building require. Extremely high level operating systems
> have advantages for some types of software (like databases where speed
> is not important). However, when controlling industrial or game =
processes,
> you need much faster access to the bits of information (like pixels,
> voxels, serial bits, and control bytes) than is possible with a =
four-level
> security layer on top of an operating system kernel. The game =
developer
> need to be able to by-pass the operating system whenever anything
> interesting in the game needs to be programmed. As an example, in
> writing software that displays a map, even a background map, you need
> direct hardware access to the memory mapped pixel in order to display =
it
> fast enough that the user does not have to wait for it, and even then,
> you have to carefully control the order of the bits and bytes you =
display,
> in order to gradually res and de-res the map up, to make up for the
> extremely low bandwidth of current CRT-type displays. Until operating
> systems realize this (as Windows NT 4 is beginning to, by granting
> programmers a little bit of access to the pixels and some ports if =
they
> buy an expensive game developers kit), programmers must resort to
> some not very nice practices in order to meet the performance =
requirements
> of the software.
>=20
>=20
with StandardDisclaimer; use StandardDisclaimer;
package Sig is
--,----------------------------------------------------------------------=
---.
--|Simon K. Johnston - Technical Architect  (C++/Ada95) |ICL Retail =
Systems |
--|-----------------------------------------------------|St Martins =
Place   |
--|Internet : skj@acm.org                               |51 Bath Road    =
   |
--|Telephone: +44 (0)1753 793600 Fax: +44 (0)1753 793636|Slough          =
   |
--|Internal : 7286 4617   OP Mail: S.K.Johnston@BRA0801 |Berkshire, SL1 =
3UG |
--|WWW URL  : http://www.acm.org/~skj/                  |United Kingdom  =
   |
--`----------------------------------------------------------------------=
---'
end Sig;




^ permalink raw reply	[flat|nested] 15+ messages in thread
* Re: Port I/O
@ 1996-11-06  0:00 tmoran
  1996-11-07  0:00 ` Michael F Brenner
  0 siblings, 1 reply; 15+ messages in thread
From: tmoran @ 1996-11-06  0:00 UTC (permalink / raw)



> > manipulation) from user code under NT or W95 rather than going through
>The obvious answer is that NT does not provide device drivers, or
>fast enough device drivers to do the kind of animation, serial control,
  Does NT *allow* user code fast (or any) access to the IO ports?




^ permalink raw reply	[flat|nested] 15+ messages in thread
* Port I/O
@ 1996-11-03  0:00 Robert P. Kuzmicki
  1996-11-04  0:00 ` Ed Falis
  0 siblings, 1 reply; 15+ messages in thread
From: Robert P. Kuzmicki @ 1996-11-03  0:00 UTC (permalink / raw)



How do you do simple port I/O with ObjectAda 7.0? I must have been programming
in 'C' too long. 




^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~1996-11-20  0:00 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
1996-11-13  0:00 Port I/O Simon Johnston
1996-11-14  0:00 ` Michael F Brenner
1996-11-14  0:00   ` Robert Dewar
1996-11-17  0:00     ` $500 <= chump change, was " Tom Moran
1996-11-17  0:00       ` Robert Dewar
1996-11-18  0:00         ` Tom Moran
1996-11-19  0:00           ` Robert Dewar
1996-11-19  0:00           ` Tom Moran
1996-11-20  0:00         ` Richard Riehle
  -- strict thread matches above, loose matches on Subject: below --
1996-11-06  0:00 tmoran
1996-11-07  0:00 ` Michael F Brenner
1996-11-03  0:00 Robert P. Kuzmicki
1996-11-04  0:00 ` Ed Falis
1996-11-05  0:00   ` Michael F Brenner
1996-11-06  0:00     ` Robert S. White

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