nesdev.org

^this.

Alegend45 wrote:^this.

Your problem is not the lack of a "good emulator" (by *your* standards ofcourse) but the lack of knowledge from your part. So yeah, a "good emulator" won't offer you something , create your super awesome/useful program FIRST and then rest assure the communities will help you debug it IF it's super awesome/useful indeed ... at this point your posts here worth nothing.

lidnariq wrote:For DOSBox, I have no idea by what you mean by "only the popular shit", because it certainly looks to me like they've got perfect compatibility with more than 85% of all games known to them. Is this the equivalent of bitching about how no famicom emulator accurately handles X random Waixing game?

Sorry, but unlike the Famicom the PC is a lot more than just a games platform. There are plenty of small businesses using what would be considered legacy DOS software thats both incompatible with modern operating systems and too expensive for such a business to replace. Tee repair section of the business I work for use a DOS version of a application called Servicebase to manage all the repair jobs. Running it on DOSBox on a newer machine just kept corrupting it's database. DOSBox can run newer DOS games quite well but can't handle a older textmode database.

The attitude that some people have with DOSBox would be like people saying that (insert name of Nintendo 80s 8 bit home console emulator here) is fine with just supporting the US releases...

Hojo_Norem wrote:
Sorry, but unlike the Famicom the PC is a lot more than just a games platform. There are plenty of small businesses using what would be considered legacy DOS software thats both incompatible with modern operating systems and too expensive for such a business to replace. Tee repair section of the business I work for use a DOS version of a application called Servicebase to manage all the repair jobs. Running it on DOSBox on a newer machine just kept corrupting it's database. DOSBox can run newer DOS games quite well but can't handle a older textmode database.

The attitude that some people have with DOSBox would be like people saying that (insert name of Nintendo 80s 8 bit home console emulator here) is fine with just supporting the US releases...

DOSBox is not made to run applications , it is made to run games. It is stated by the authors a gazillion times. It is not to be trusted for serious stuff.

I hate to say it, but DOSBox does have the best VGA emulation out of all of them.

keropi wrote: DOSBox is not made to run applications , it is made to run games. It is stated by the authors a gazillion times. It is not to be trusted for serious stuff.

I understand that now but back then the name 'DOSbox' made me think thats what it did, emulate a DOS box as in a DOS environment. Perhaps the name "Old-non-windows-pc-game"box would be more descriptive.

At least the printer emulation worked.

Anyhoow, anybody tried PCem? Seems capable enough, the developer even says it can run Win98.

I doubt that highly. Making a PC emulator that runs Win98 is not a one-man job.

Hojo_Norem wrote:There are plenty of small businesses using what would be considered legacy DOS software thats both incompatible with modern operating systems and too expensive for such a business to replace. The repair section of the business I work for use a DOS version of a application called Servicebase to manage all the repair jobs. Running it on DOSBox on a newer machine just kept corrupting its database. DOSBox can run newer DOS games quite well but can't handle a older textmode database.

So have you told them? Have you tried any of the other x86 emulators? Do you know whether the corruption issue wouldn't have happened with a cyrix/amd x86 cpu? Or whether it's sensitive to the version of DOS? I encountered a "problem" where DOSbox always presented the directory entries in alphabetic order, and $person had been using the file entry order of the disk to organize things.

The attitude that some people have with DOSBox would be like people saying that (insert name of Nintendo 80s 8 bit home console emulator here) is fine with just supporting the US releases...

At no point have I said that DOSBox is the pinnacle of PC emulation. I'm simply pointing out that they can't fix what they can't directly debug.

For retrodev, even byuu says that bsnes is not sufficient to make sure that your game will work correctly on hardware. Even Trixter agrees that emulation can never replace the original hardware.

DOSbox works well enough for me to run windows 3.1 software. (Although, honestly, so does dosemu using its v86 mode on an ia32 host).

lidnariq wrote:So have you told them?

After reading through their forums and seeing the various responses to the "can DOSBox run my non-game application" I got the impression that they didn't really want to know.

Have you tried any of the other x86 emulators?

No. At the time I didn't know of any alternatives and we needed that system working yesterday. Eventually we managed to source a DOS compatible laser printer and built a new FreeDOS powered box. Still the downtime did cause some aggro for the service guys.

Do you know whether the corruption issue wouldn't have happened with a cyrix/amd x86 cpu? Or whether it's sensitive to the version of DOS?

I can't really comment on the CPU (anyhoow, you'd think that the DOSBox team would be striving for intel compatibility and the old box was a genuine intel 486 and the new one a early Pentium) but Servicebase is happy running in FreeDOS as it was in MS-DOS 6.22

At no point have I said that DOSBox is the pinnacle of PC emulation.

And at no point did I make any suggestion that you did. More like I was taking a stab at the general idea of "its good enough". It's good enough meant that Mario Kart was emulated for ages before Pilotwings was for example. Its good enought is partly the reason why Nesticle lasted so long...

For retrodev, even byuu says that bsnes is not sufficient to make sure that your game will work correctly on hardware. Even Trixter agrees that emulation can never replace the original hardware.

Preaching to the choir there

Game consoles are all the same. Every NES you come across is going to have the exact same hardware, functions, and capabilities. Same with every Sega Genesis, every Xbox, every Astrocade, every Atari 2600, every Nintendo 64, etc.

This makes them easy to emulate, because all of the software is designed for this one particular set of features.

PCs are customizable and expandable to no end. One PC will have wildly different features and capabilities compared to another. There's no "standard behavior" because, for example, nVidia graphics hardware and Intel GMA graphics hardware, while adhering to several standards (such as OpenGL and SVGA), will still differ significantly in clockspeeds, bandwidth, etc.

So! PCs wildly vary from one to another, NESes do not.

I guess the most plausible PC emulator would be one that emulates a generic IBM PC compatible with Soundblaster-compatible sound hardware, a generic VGA graphics board, and maybe a 486 CPU. So basically, the most generic computer imaginable. This would definitely work for anything pre-Windows 95, and possibly early Windows 95.

Yeah, but I'd try to emulate as many different video cards and sound cards and chipsets as I possibly could.

Alegend45 wrote:Yeah, but I'd try to emulate as many different video cards and sound cards and chipsets as I possibly could.

Surprisingly, the vast majority of them seem to boil down to VGA compatible or Soundblaster compatible. Provide generic VGA and generic Soundblaster emulation, and you'll support a very large portion of PC software right then and there.

Alegend45 wrote:Yeah, but I'd try to emulate as many different video cards and sound cards and chipsets as I possibly could.

Assuming we're talking about all aspects of PCs here (that's what your OP implied) and not just classic DOS-era hardware:

I don't think you understand the situation in full (I'd border on saying you definitely don't understand the situation in full). Emulating mainstream video cards made after roughly 1996 (around the time the 3dfx Voodoo was introduced) is amazingly difficult without someone who can actually sit down and reverse-engineer the device at the hardware level. Why the complexity? Because all product documentation was (and still is -- the situation has only gotten worse) under NDA.

I speak the truth and from personal experience as well. Short story: in 1993 I wanted to give a shot at using actual hardware-accelerated features of the video card I happened to own (a VLB card using the ET4000/W32 chipset). However, as I expected, there was no documentation for the acceleration features of this card. Sure, the card manufacturer offered 3D Studio drivers (whoop dee doo), but most every other application I found (including X drivers) just used VESA -- i.e. no actual hardware acceleration capabilities of the card. I knew the card had features like smooth screen panning, hardware sprite support, masking, and some basic 3D capabilities (reminder of what year this story takes place), and I wanted to tinker with those, yet I had no idea how. I was used to classic 320x200x256 (segment A000) mode.

I decided to contact Tseng Labs directly -- I did this because in the past I had contacted companies (specifically Zilog) to get information on their chips and was greeted by folks who sounded thrilled that I wanted docs, so I moronically assumed that it'd be the same with PC hardware manufacturers. My first call with Tseng consisted of telling them the truth: I was just a generic hobbyist wanting to tinker. I still remember the call: I was handed to some manager somewhere and was politely yet very directly told "sorry we don't do that". A few weeks later I tried a different approach: I explained to the gal at the front desk that I was working on a combination of a hardware/software project and that I needed product documentation since we were considering the ET4000/W32 chip for our device. I was handed to some other manager, who asked me to explain in detail the project and how many chips we'd be looking at using, so I made some shit up on-the-fly (I said for starters a few hundred chips). After an uncomfortable delay the person responded that they could ship technical documentation to me, assuming -- and I quote -- that "I gave them my word that I would not distribute or copy it". A week later I had the documentation (around 40 double-sided pages if I remember right).

Was I able to accomplish anything? Not really -- the documentation was mainly for hardware implementation (i.e. stuff someone designing a circuit or card would need for interfacing with the chip), and the software side of things was tiny (a few pages at most). The software bits were obviously translated and badly at that (that year I was a 3rd-year Mandarin student and was fairly certain the conversion was from Chinese to English, but I still remember second-guessing myself sometimes). I wasn't going to get any actual support from Tseng -- think about what schmooze I had to go through just to get what I did? -- so I was out of options. I gave up. The end.

Fast forward to today and think about NDA, IP, and DMCA. Now ask yourself the question: do you really think it's possible for you to "emulate as many video chipsets as possible" when you have access to absolutely no official documentation? If you think the answer is "yes", you've got your head buried deep in the (hopefully sweet-tasting) sand. Reverse-engineering is a very lengthy process, and is in no way/shape/form easy. Hell, you're on a nesdev forum, where all public documentation for the console itself has consisted of reverse-engineering efforts -- that console came out in 1983 and folks here are STILL trying to figure out its behaviour. Even open-source operating systems like Linux end up getting handed binary blobs from companies like nVidia (graphics chips) and Broadcom (wireless NICs and switching fabrics), citing IP. AMD has pulled PR stunts insisting they "want to help Linux and provide the documentation" yet the documentation they've given has been sub-par (from what I understand). OpenBSD has tons of songs talking about this predicament (see the descriptions for songs "100001 1010101", "Puffy Baba and the 40 Vendors", "Blob", "Hackers of the Lost RAID", and "Wizard of OS").

So how's that sand? :-)

Now, assuming we're talking about DOS-era hardware: above still applies, just to a lesser degree; see below.

Drag wrote:Surprisingly, the vast majority of them seem to boil down to VGA compatible or Soundblaster compatible. Provide generic VGA and generic Soundblaster emulation, and you'll support a very large portion of PC software right then and there.

Assuming we're still talking about classic DOS-era stuff -- correct, but don't forget about VESA/VBE. I feel sorry for anyone having to emulate that.

I wouldn't be surprised if these un-publicly-documented video chips were full of bugs. Since the supplier provides the software driver, and updates it many times at first, it's likely that only the combination of the driver and video chip has a low bug count. They can work around bugs and avoid features which turned out too buggy to use (at a performance cost). Since only their driver uses the chip, they don't even need very good documentation at all.

Well, koitsu, I do at least plan to start with the small stuff, like the MDA, clones, CGA, clones, etc. The only problem I need some help on with clones, is how to scan for extra registers. My first step would be to find them.

EDIT: I also know that this will be a lifelong goal I will never reach. Some obscure cards have probably already gone to the sands of time. However, I can't stop until I'm dead, if I want to preserve the PC. My project will perhaps never be finished. However, I will at least do the best I possibly can, for as long as I possibly can.