Question Is this document accurate?

[ar81]

I have been making this PDF to help people who need to emulate old systems.

I wonder if there is any inaccuracy that may need to be corrected.
I also wonder if it should be at OH or not.

 

[IronRain]

I've never emulate an old OS, but with this 'walkthrough' it should definitely work. very clear and it's also nice that you explain every step you take

 

[Artlav]

Nothing badly wrong on a quick read, sounds like a useful guide.
Although, i just use an old PC in a shoe box to play these cool DOS games.

 

[MeDiCS]

Yes.

-Sound, video and drivers in general rely on the OS.
-AFAIK, an OS doesn't rely on the BIOS except for startup processes.
-API is not properly explained, and may not even be needed.
-OpenGL is not Nvidia's.
-The evolution of the OSes is dead inaccurate. Where's OS/2? Windows-family and Unix-family of OSes aren't the only ones in existence.
-Sources missing.

In general, it's hard to read and understand, there lots of other bugs, and it isn't clear what's your target audience (use of non-technical and very-technical terms together).

 

[cjp]

I'm currently reading page 2. The first thing I noticed was a mismatch between the title on the first page and the contents on that page. The contents seem to apply to modern systems as well as old systems. Secondly, Adding a document title (not just a chapter title) may help, and a small introduction to what the document will cover, and who are the intended audience.

The first real mistake I see (sorry, but I'll focus on the mistakes) is on page 2: OpenGL is not created by NVidia. Instead, the first version was created by SGI, and more recent versions are maintained by a consortium that consists of many companies, and one of them is NVidia.

I'll make more posts while reading.

---------- Post added at 07:17 PM ---------- Previous post was at 07:11 PM ----------

Page 1: CPU only refers to the processor. CPU and processor are really synonyms. The only difference is maybe that any unit that processes data can be called processor, and the CPU is just the central processing unit. An other example of a processor is the graphics processor on the video card. There are probably other small processors in a PC, but you usually don't have to worry about them.

 

[Enjo]

Sorry but I don't have time for essence review, so I can't tell much except for these three critical words -

1. I have no idea why I should use the wrappers from the last pages. Some description is necessary
2. For completeness, I would absolutely put info about ScummVM, which technically is in no way emulating old hardware, but it lets you flawlessly play old games which is the point of interest of the majority of your readers
3. If you created that PDF in OpenOffice, you could export the table of contents along with the text. If you're interested in this, then let me know and I'll tell you how to do it. It's not that intuitive

I also wonder if it should be at OH or not.

I can't see a reason why it should... I could ask the same question about my MDDClone-SDL game. After all you can fly there as well

http://www.orbithangar.com/faq.php

6. What is this site about? What are these downloads for? This site is essentially a file hosting server for modifications and add-ons to the space flight simulator Orbiter ( http://www.orbitersim.com/ ).

If you want the documentation to be more visible to the world, I suggest putting it on a blog page with proper keywords. Google takes care of the rest and every time somebody enters "Emulating old systems" in Google (which means that he's very interested in this topic), will find your page on one of the Google's pages... well you know how it works

 

[ar81]

Yes.

-Sound, video and drivers in general rely on the OS.
-AFAIK, an OS doesn't rely on the BIOS except for startup processes.
-API is not properly explained, and may not even be needed.
-OpenGL is not Nvidia's.
-The evolution of the OSes is dead inaccurate. Where's OS/2? Windows-family and Unix-family of OSes aren't the only ones in existence.
-Sources missing.

In general, it's hard to read and understand, there lots of other bugs, and it isn't clear what's your target audience (use of non-technical and very-technical terms together).

How would you explain API? Graphics rely on API, not on direct calls to hardware drivers.

What other OS families should be worth mentioning? Where do they come from?

---------- Post added at 05:28 PM ---------- Previous post was at 05:23 PM ----------

Sorry but I don't have time for essence review, so I can't tell much except for these three critical words -

1. I have no idea why I should use the wrappers from the last pages. Some description is necessary
2. For completeness, I would absolutely put info about ScummVM, which technically is in no way emulating old hardware, but it lets you flawlessly play old games which is the point of interest of the majority of your readers
3. If you created that PDF in OpenOffice, you could export the table of contents along with the text. If you're interested in this, then let me know and I'll tell you how to do it. It's not that intuitive

Wrappers are useful when games were made for 3DFX. Perhaps I should mention it.
I do not know anything about ScummVM since I have never used it. Where could I find more info?

I used Word, not Open Office, and then printed as PDF. Perhaps I should move to OO.

 

[MeDiCS]

How would you explain API? Graphics rely on API, not on direct calls to hardware drivers.

That depends on who you think will read it, as an explanation (or mention to API) may not even be needed. If you think you should, API can be explained as a 'language to talk with the driver/OS, like English', or any other string using common nouns. A 'collection of libraries' is very opaque and technical to the casual user.

What other OS families should be worth mentioning? Where do they come from?

Again, depends on your scope. If it's worth mentioning MULTICS, it's worth mentioning OS/2. See Wikipedia for some details.

 

[cjp]

How would you explain API? Graphics rely on API, not on direct calls to hardware drivers.

I think APIs are important for understanding how computers work, and why they sometimes don't.

It is important to realize that some(*) APIs make games independent from specific types of hardware, because the game only has to talk to the API, which looks the same on all hardware, while the API takes care of supporting all different sorts of hardware. For each piece of hardware, a different driver is used. A driver is a piece of software that can translate instructions from the API to instructions for a certain piece of hardware.

The distinction in the PDF between drivers and APIs is not really correct. An API is the boundary between different layers of software: it's the "language" both blocks have to speak to each other. So, every driver has an API. The important difference is that some APIs only have a single driver for a single piece of hardware: e.g. AFAIK the Glide API only has drivers for 3DFX cards. Some APIs are only designed with a specific piece of hardware in mind, which makes it difficult (but not impossible) to make drivers for other hardware.

(*) not all APIs do this, but especially when it comes to access to hardware, making the application independent from the hardware is often the purpose of the API.

 

[Enjo]

Wrappers are useful when games were made for 3DFX. Perhaps I should mention it.

That's what I thought, but still, I'm a techie who was able to realise that. Just a few words of intro on that topic should be enough

I do not know anything about ScummVM since I have never used it. Where could I find more info?

How about The G Page?
In a nutshell, it's a multiplaftorm reimplementation of interpreters of the original adventure games which are supported. The list is quite impressive.

 

[cjp]

Again, depends on your scope. If it's worth mentioning MULTICS, it's worth mentioning OS/2. See Wikipedia for some details.

While I think it's worth mentioning APIs, I don't think it's worth mentioning MULTICS, when the topic is gaming. And even if you do, I wouldn't place it directly above DOS in the diagram. The historical influence towards UNIX is much more direct than towards DOS. In fact, I think DOS is partially, indirectly, influenced by UNIX.

But that's history, and history isn't an exact science. For the rest, I'll try to focus on the technology aspects.

 

[Enjo]

Right. History is written by victors.

[EDIT]

Ah, BTW - that table of contents in OOo is visible in the left panel, where if no table is present, you only see pages miniatures. It's quite comfortable to be able to click on that panel to move quickly to the topics that interest you

 

[cjp]

Page 4: your memory layout is incorrect. It should be:

First 640kB: Base memory, used for applications, and originally also for DOS and drivers.
640kB..1MB: Upper Memory Area. Originally meant for communication with hardware, such as the video card and hard drives. Later also used for EMS blocks (which are continuously transported between UMA and the EMS location), and for some system software.

High Memory Area: first 64kB of Extended Memory. More recent versions of DOS can place themselves here, so that more base memory is available for applications.

Read Wikipedia on everything you are writing down. Wikipedia is not always correct, but on average it's more accurate than your text.

---------- Post added at 08:12 PM ---------- Previous post was at 08:00 PM ----------

Page 5: Windows 2000 is NOT Windows 98 with(sic) steroids. It is Windows NT on steroids.

There are three major branches of windows versions:

1:
windows 1
windows 2
windows 3.x

2:
windows 95
windows 98
windows ME

3:
windows NT
windows 2000
windows XP
windows Vista
windows 7

This is also why DOS games don't work very well on windows XP: families 1 and 2 are based on DOS, but family 3 only contains a very limited DOS emulator.

Windows 2000 was supposed to attract home users to family 3, but it failed, so m$ had to release windows ME. Windows XP did what windows 2000 was supposed to do.

---------- Post added at 08:18 PM ---------- Previous post was at 08:12 PM ----------

Page 5: is it really true that DirectX < 6 is unsupported in windows XP? I can't remember something like that. Can you give me some links to websites that confirm this?

---------- Post added at 08:30 PM ---------- Previous post was at 08:18 PM ----------

Page 5: on DirectX 10: "supposed to be" are the right words. I don't think DirectX 10 provides much beyond DirectX 9. DirectX 8 was a major improvement though, with much better support for programmable graphics processors.

Translating older calls to DirectX 10 calls is the proper way to support all versions of the API. I think older versions of DirectX also had a system where old APIs were emulated on top of the latest version. This really adds only a little bit of extra work, and that isn't so important generally, because older games are designed for having less CPU time. The alternative would be to let each version of DirectX have its own driver, which would mean a lot more work for driver developers, which would make it less likely that a certain combination of DirectX version + hardware will be supported.

Yes, the war between DirectX and OpenGL does hurt the industry, or, IMHO, DirectX hurts the industry. But this is not different from other other cases in computer technology where there's not one widely accepted open standard.

 

[Enjo]

Yes, the war between DirectX and OpenGL does hurt the industry, or, IMHO, DirectX hurts the industry. But this is not different from other other cases in computer technology where there's not one widely accepted open standard.

Some well known company hurts the industry by enforcing its own standards even when there are already widely accepted open standards, like ODF being accepted to be ISO format.

Pssst! It's just a matter of clicking on Save As and choosing doc, instead of clicking on Save.

 

[MeDiCS]

Some well known company hurts the industry by enforcing its own standards even when there are already widely accepted open standards, like ODF being accepted to be ISO format.

Pssst! It's just a matter of clicking on Save As and choosing doc, instead of clicking on Save.

Hmm, I think you mean OOXML, and not ODF.

 

[cjp]

Page 11: You meant 'Hercules (monochrome)' to be a list item, didn't you?

Other comment: DOSBox RULES!!!!

 

[Enjo]

Hmm, I think you mean OOXML, and not ODF.

I meant ODF. So OOXML also got into ISO? Drats!

[EDIT]
Check the last paragraph HERE

 

[cjp]

Page 15: it is not true that sound of a lower sampling frequency is not heard as a continuous wave. The only problem with lower sampling frequencies is that higher sound frequencies are not present in the sound. How this sounds partially depends on what the sound card makes of it, but compare e.g. telephones, which use much lower sampling frequencies.

In fact, the highest audible frequency is about 20kHz, and to represent that frequency, you need a sampling frequency twice as high, so 44100 Hz is the lowest sampling rate where nobody hears distorted sound. That's why it is the most popular sampling rate. 48kHz is just for systems where a bit of error margin is desired, e.g. for sound editing.

Besides sampling rate, the number of bits per sample is also important, but if your program doesn't allow to set it, then I guess it's irrelevant in this context.

 

[ar81]

Page 5: is it really true that DirectX < 6 is unsupported in windows XP? I can't remember something like that. Can you give me some links to websites that confirm this?

I have lots of games. Those that use DirectX5 or lower simply do not work with compatibility fix. Yeah, probably I should get rid of that statement. But I also would like to know how to make them work.

 

[MeDiCS]

I meant ODF. So OOXML also got into ISO? Drats!

[EDIT]
Check the last paragraph HERE

Wait, you lost me. You're saying that ODF was pushed by Sun as a standard, even though there are already-standard (i.e. ISO approved) formats such as Microsoft's DOC format? Could you also clarify the reason you included that link?