PC still playing Amiga catchup

[jkirk]

You are thinking doing multitasking while someone is accessing directly the hardware and trying to avoid conflicts, but I am talking about just allowing an application to use hardware directly.  You can do that with IOPM or Amiga does it by the application not allowing other applications to run at the same time.

locking up the hw so only one program can access at a time is not my idea of an efficient way of doing things. furthermore in this environment of multitasking this is not feasable.

But they also fixed bugs in higher and higher versions of DirectX; so you need to know whether to avoid the bugs or not.  

bugs? what bugs? srry but if a bug exists the only person that has to deal with it is the programmer and driver writer. the end user don't see the issue typically.

No, you don't need an API.  Windows for each task keeps track of an IOPM and it can set IOPM to enable hardware ports needed by that application and application directly accesses that port without any API/drivers involved.

you are missing my point. iopm to my knowledge has no error correcting built in. it opens the ports for one app then if that app crashes iopm don't immediately close the ports and reset the hardware. then the next app comes in but either can't open the port or open it then crash. an api can detect and correct as well as make programming more uniform.

[jkirk]

Sorry, 10 of the 12 machines I have do not have serial ports but have parallel ports.

and all 5 of mine and the 6 computers i have worked on did have serial and parallel. as well as the 3 computers i have at work.

Sorry, gameport is more recent than you think.  

sorry but 1990 is not recent. also if it was that recent microsoft wouldn't have dropped support for it.

You miscomputed.  Game ports were on motherboards in 1990s as well as on audio cards.  I bought an audio card w/gameport just a few years ago.

are you sure? i coulda sworn 1990 - 1984 = 6
birth year of both are only 6 years apart.

Original point was that someone is giving a hoot about gaming interface.

no your point as stated was that you believe someone created the hardware because they cared about the poor performance of the joyport. the hardware transition was more about eliminating old standards to reduce cost. even if the usb interface had no performance increase they still would have eliminated the joyport(among other ports) since they would not have to license the use of many ports and could focus on one style of input port.

[ElPolloDiabl]

in this enviroment of multitasking this is not feasable.

Not trying to turn this place in lolcats, but:


Did you mean: environment

[persia]

Classic Amiga isn't competing against anything, the company that produced it went belly up 15 years ago.  It's a hobby machine that some of us find fun to play with, it's a bit of history.  It's a great learning tool to learn the basics.  Modern OSs do everything for us, the Amiga doesn't, it forces you to understand what you are doing and do it manually.  There is no competition for classic Amiga except the competition against time and electronics...

Classic Amiga wasn't a serious threat against SGI and it's OpenGL standard. Both ATI and NVIDIA follows the SGI’s approach.

Classic Amiga is not competing against the “PC” i.e. it’s competing against redressed old school RISC vendors e.g. DEC (AMD, Intel, Microsoft), SGI (ATI, NVIDIA).

[jkirk]

Did you mean: environment

you right i don't spel wel when i an in a hurry.

[Wayne]

Classic Amiga isn't competing against anything, the company that produced it went belly up 15 years ago.  It's a hobby machine that some of us find fun to play with, it's a bit of history.  It's a great learning tool to learn the basics.  Modern OSs do everything for us, the Amiga doesn't, it forces you to understand what you are doing and do it manually.  There is no competition for classic Amiga except the competition against time and electronics...

THANK YOU!  Someone actually "gets it".

Wayne

[amigaksi]

and all 5 of mine and the 6 computers i have worked on did have serial and parallel. as well as the 3 computers i have at work.
...

That doesn't prove that serials are preferred over parallel.  They did have both and then they dropped serial before parallel.

>sorry but 1990 is not recent. also if it was that recent microsoft wouldn't have dropped support for it.

Hello, AT DIN5 connectors went a long time ago before gameports.

>no your point as stated was that you believe someone created the hardware because they cared about the poor performance of the joyport. the hardware transition was more about eliminating old standards to reduce cost. even if the usb interface had no performance increase they still would have eliminated the joyport(among other ports) since they would not have to license the use of many ports and could focus on one style of input port.

Sorry, but they made newer joysticks for USB-- they had to substitute with something.

[amigaksi]

Today, they're called exploits, and both hardware and software vendors are under extreme pressure from trillion dollar industries to close them as quickly as possible.

But they (hardware bugs) are useful to have around if they help to make better more optimal software.

[amigaksi]

Lots of instructions have implied locks, but I was talking about port-based I/O specifically. Latency aside, I'm curious about the implications to multiprocessor systems. In a NUMA system, if remote nodes are not prevented from executing while another node is busy, you could run two I/O-related threads out of phase, preventing stalls and linearly scaling the performance of the system, i.e. it would be perfectly parallel--in so far as the system allowed. You'd still have to deal with latency, but only per-processor. While one processor is waiting on the next I/O, the other processor is processing the previous I/O. I need to look at the AMD manuals.

Well go look at the manuals because I don't think you can parallel process two I/O instructions.
Implicit locks are only on XCHG as far as documentation on Pentium that I have.

[amigaksi]

Well, I'm not sure about Amiga games -since I didn't seriously look into how their inner loops work- but I am sure about C64 and other 8 bit games.

On these machines the CPU is usually the limiting factor and most games just run one game loop per frame displayed. On the C64, since most interesting things are done through clever usage of interrupts, this effectively means a 50/60Hz polling rate for user input*.

On machines without raster interrupt such as the Spectrum it's more tricky to accurately say, but the average Spectrum game is quite lucky if it actually reaches a 60Hz update cycle for it's graphics. And since these games also update input once a frame at best you get a roughly 20-60Hz polling rate for user input*.

Now, like I said, I'm less sure about this on the Amiga. But I'm willing to state that most games on it will still follow the same model: update (most) everything once a frame, leading to a 50Hz/60Hz joystick polling frequency.


On a sidenote, the average human adolescent has a reaction time of about 215 milliseconds (http://en.wikipedia.org/wiki/Reaction_time), this drops with age. This translates to a reaction time of slightly over 10 frames (at 50Hz).

*) The assumption here being that the designer did not deliberately slow down reading user input. Though I've not seen this myself I'm pretty certain that a game updating its screen at 25Hz can get away with sampling the joystick at 25Hz without people noticing this much if at all.

Problem is more about getting all states of joysticks regardless of what a human's reaction time is.

[amigaksi]

locking up the hw so only one program can access at a time is not my idea of an efficient way of doing things. furthermore in this environment of multitasking this is not feasable.
...

It is efficient-- that's what I meant by taking over the hardware.  So some critical application can write the most optimal game or application.  OS still exists and can do it's own multitasking.  See Amiga computer as an example.

>bugs? what bugs? srry but if a bug exists the only person that has to deal with it is the programmer and driver writer. the end user don't see the issue typically.

We are talking about programmer.

>you are missing my point. iopm to my knowledge has no error correcting built in. it opens the ports for one app then if that app crashes iopm don't immediately close the ports and reset the hardware. then the next app comes in but either can't open the port or open it then crash. an api can detect and correct as well as make programming more uniform.

No, IOPM will only protect disk i/o or other things it doesn't want accessed and allow application to go directly to hardware and leave it to application if it wants to crash itself since it won't hurt the OS.

[amigaksi]

Classic Amiga isn't competing against anything, the company that produced it went belly up 15 years ago.  It's a hobby machine that some of us find fun to play with, it's a bit of history.  It's a great learning tool to learn the basics.  Modern OSs do everything for us, the Amiga doesn't, it forces you to understand what you are doing and do it manually.  There is no competition for classic Amiga except the competition against time and electronics...

There are still things Amiga does that modern PCs cannot do.  In fact, many retro machines allow for doing things in more accurate manner than PCs and Amiga is the top gun of those machines.  Have you ever written some method of timing how long a piece of code takes on a PC?  Take into account the caching, various CPU frequencies, power management, C1 states, memory speeds, I/O speeds, etc.  

And what makes it all the worst-- APIs!   You don't know what code is behind the APIs on different systems.  It's  all hodge podge when it comes to estimating time of code.

[Trev]

Well go look at the manuals because I don't think you can parallel process two I/O instructions.
Implicit locks are only on XCHG as far as documentation on Pentium that I have.

Sorry, I started speaking in general terms, i.e. lock as opposed to LOCK#.

So, I looked at the manuals, and in a multiprocessor system, two processors can run I/O in parrellel, e.g. execute IN simultaneously. Whether or not they can access the same port simultaneously is up to the target device and whatever is doing bus arbitration.

[smerf]

OK, you know that was a silly comment. Of course Windows can run for a year without a "crash." You're not likely to run a video player or a game on consumer grade hardware for a year without a crash, but you're also not expecting 100% uptime under those conditions.

Hi,

UHHHH, Maybe if you only use a Windows installed computer once or twice a year, come to think of it I have never seen a Windows computer that is used every day go without at least 2 crashes a year, that is why the place where I work has an IT department staffed with about 200 personnel, they are either fixing computers or re-installing windows on them. My one last thought, would you board an aircraft if you knew that windows was running all the digital instrumentation on it?, or would you drive a auto if you knew windows was running your auto computer?

Now my A4000 which gets turned on for use at least twice a week hasn't crashed since 1993 and still has my data on it since then, and I must admit my 2 gig hard drive is getting quite full, I still have about 1.2 gig free for use, might be another 10 years and I will have to think about installing a larger hard drive.

PC users can you claim this?

smerf

[Hammer]

Classic Amiga isn't competing against anything, the company that produced it went belly up 15 years ago.  It's a hobby machine that some of us find fun to play with, it's a bit of history.  It's a great learning tool to learn the basics.  Modern OSs do everything for us, the Amiga doesn't, it forces you to understand what you are doing and do it manually.  There is no competition for classic Amiga except the competition against time and electronics...

I was mainly referring to SGI and DEC during the early 90s.

[Karlos]

Now my A4000 which gets turned on for use at least twice a week hasn't crashed since 1993 and still has my data on it since then, and I must admit my 2 gig hard drive is getting quite full, I still have about 1.2 gig free for use, might be another 10 years and I will have to think about installing a larger hard drive.

PC users can you claim this?

smerf

My work PC had an uptime of over 1 year until a power cut took it down. That's one full year of running a full desktop environment, without crashing or manual rebooting.

It was running fedora 5. After the reboot it was running fedora 10