Porting DOS dsims?

Visual Novel Community Off Topic
#1

I am the proud owner of a few older JAST titles for MS-DOS. Unfortunately, since getting a newer computer system with WinXP I have been unable to play them.

Not-so-recently I stumbled upon the very well done Mirror Moon “Tsukihime” English translation, which due to the nature of the game uses the same data files as the original, with a different engine/executable. As a hobby programmer myself, this prompted me to think, maybe the same thing can be done with these DOS games, that is, create a Windows executable that can read the original data files. I started reading through them with a hex editor… and realized just how hard this might be.

The question behind all this rambling is: does anyone have or is JAST willing to share information on the graphics (.GRA) and script (.OVL) data format for these games? I have made some progress with the OVLs (I think) but the GRAs have me completely stumped; I can get the width and height but not much more, as it seems to use some type of compression.

(P.S. If anything ever comes of this project, of course, I have no intention of distributing game files; only the new executable, so that others can enjoy their games in Windows too. :slight_smile:

(P.P.S. Better yet, if there’s already such a program available, can you point me to it?)

EDIT:

All but unable. I have a much older system I can use, but would rather not.

[ 03-31-2007, 03:12 AM: Message edited by: CompMan44 ]

#2

Can always try dosbox to try to run those oldies. I’ve tried it on a few of my ENGLISH dos games and it seems to work.

#3

That’s what I’ve been doing. Among other issues, it has a monochrome LCD-- I can hook it up to a color monitor, but I’ve only got one of those, and it’s usually connected to my XP computer. Besides that, though, I especially want to do this as a proof-of-concept programming exercise. n_n

And yes, they are in English; that’s not a problem.

#4

jast has released a xp-compatible compilation for these games so you may want to look into those

#5

really ought to keep up on these things

Really? Wonderful, something else to save up for. ':slight_smile:

Meanwhile, I guess I’ll continue my… “analysis.” Thanks anyway.

#6

product info:

http://www.peachprincess.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=PP&Product_Code=J006&Category_Code=BGJU

[ 03-31-2007, 12:22 PM: Message edited by: Lamuness ]

#7

There’s also the Legend of Fairies and Fairy Nights game available - http://affiliates.jlist.com/click/946?url=http://www.jlist.com/PRODUCT/FAIRYSET

These are the recently released download versions. I think they’re only available as a bundle for the time being though. With affiliate link added :slight_smile:

#8

He didn’t mean to use a PC with DOS on it, but DOSBox, a DOS emulator.

#9

That’s exactly the titles I’m looking for, Lamuness. n.n Hmm… well, except Runaway City; oddly enough I haven’t heard of that one. At $20 for all three, I may as well check it out.

Progress: OVLs are pretty much plain text, as far as I can tell, with some bytecode in between for scripting. Most of the GRAs have “JAST” in the header. And still no luck decoding them. (For now I’m assuming they’re all 16-color, considering the technology.)

…On a side note, damn you, US legislature. If you hadn’t made all the girls in my games “18 or older” that hot little junior down the street might still be— er, wait, that was just a dream. Ehehe!

[ 03-31-2007, 04:58 PM: Message edited by: CompMan44 ]

#10

…Ohhhhh. Not a bad idea. Thanks.

EDIT: Works great. In fact, it has sound now, one thing my real “DOS box” didn’t have. :slight_smile:

EDIT again: Well, “Three Sisters’ Story” works great. “Season of the Sakura” doesn’t, but I’m not sure if it’s DOSbox or the game itself.

[ 04-02-2007, 03:17 PM: Message edited by: CompMan44 ]

#11

CompMan44 I would have to guess that your using version 0.70 and I have heard on the DOSBox forums that it has made things worse in some places so you could try using version 0.65 and see if that works but I might have to host a copy of the installer since the DOSBox download section doesn’t have a download for that version (although it could be another problem)

#12

Well, I’ve noticed that even Three Sisters has… issues, for instance crashing when I try to save. So does Runaway City (now that I found it-- the old version, that is). But Sakura doesn’t want to start up at all.

The newest version of DOSbox available on the site (besides 0.70) is 0.63, so I’m going to try that and see if anything changes.

EDIT: I guess 0.63 is all they had listed, but 0.65 is available after all. n_n

EDIT: Sakura still won’t work. I guess it just doesn’t like me. Plots to remake his junk XP PC into a SUPERDOSBOX

[ 04-09-2007, 03:41 PM: Message edited by: CompMan44 ]

#13

If you’re serious about a superdosbox, well, you can install Windows 95 or Windows 98 SE on it. Their DOS compatibility is great, and you’d still have Windows that way.

#14

i have had old dos games that cant run under win9x’s setting, mainly because of memory requirements

not to say that dosbox is a whole lot better either, but all things considered it’s a worthwhile solution

#15

That’s a pretty good idea, actually. Then I can play the 95 ones that hang in XP, too. n.n

(It was going to have Linux on it, but the installer kept crashing for no apparent reason, and I’m not well-versed enough in *nix to try it manually… sigh Had to find something to do with the machine.)

#16

The original version of Sakura had some bugs. I remember the game crashed for me quite frequently. Certain of the FX seemed to trigger it; I know someone made a patch that was supposed to fix it. I don’t think I’m allowed to talk about the circumstances surrounding my possession of this game eight years ago, and bringing up the patch is frowned upon.

#17

Yeah, true. Some games require the full 640 kB low memory space, and if even a couple kB aren’t available, it won’t run. Win9x uses low memory for the regional settings.

From what I hear, for playing DOS games, the order of configurations, from best to worst, is this:
DOS > Win9x > DOSBox > WinXP

#18

Well, I never seemed to have trouble with it under “real” DOS, at least not that I can recall. As for this patch, as long as it’s legitimate (not necessarily “official”), why is it “frowned upon”?

#19

Unfortunately, many companies, who publish these old DOS games, went bankrupt (go out of business).

I sincerely hope the “JAST USA & Co” will release new “old DOS H-games” from these defunct companies.

Games as “True Love”, “Cobra Mission”, “Metal & Lace”, etc.

#20