iPhone: iDOS 2.0.1 is available (Pulled again)

03-10-2012, 02:16 PM
Joined: Jun 2010
Location: Beaufort, SC
Posts: 316
Try renaming your cfg file so it's all caps, and adjust the plist to match. I don't know if that will matter, but all of mine follow that format and work fine.
03-11-2012, 06:33 PM
looks there is no way to put in Master of Magic as its almost 30Mb

is there a solution to put 30 mg in to im1 file?

what was that post about that we will be able to add games from iso images?
does it work?

03-22-2012, 04:05 PM
Joined: Mar 2012
Location: Cincinnati, OH
Posts: 11
I'm having the same problem that shirohagen had with iDOS 2.0.1:


Set the game files up, copied to appropriate folder, clicked on the store, installed my custom app, it shows as installed, I click on it but instead of running it takes me to the C: prompt.

Any ideas?
04-02-2012, 07:47 PM
32 MB image working, bigger should be np

Hey guys, after finding Aemula in the app-store yesterday and having some fun jumping around on my pogostick in Keen, I wondered if there was more to be done with this app... some googeling later I found this thread, and armed with the knowledge of the previous posts (thank you Menneisyys!!) I made some own 1.4mb disks, quickly bumping into the size limit... I wondered if there was still more to be done with this app. The wolf3d.im1 and duke2.im1 are bigger after all, but they have a different header configuration. It's been some 20 years since I last used a hex editor (hacking the color palette of Dune2 to make Harkonen units grey, I was 11 and red was for girls, not the mighty Harkonen, so there! good excuse!) so things went all but smooth today and I learned more about FAT's, MBR's and whatnot than I could ever possibly use nowdays, but I would like to share my findings with you guys!

Now I do not wish for this app to get pulled off of the appstore, and this is my first post here so not sure who/what/where, so perhaps some screenshots to show my findings, and I try to add some explanation along the way... Let me know if I can post more! :-)

First successful boot of my home-brewn .im1 file! (but by far not my first boot attempt, lol)

Now I had a lot of trouble getting disk-writing to be successful, long after the first successive 8,16,32 and 64mb im1 boots (more should be possible, I see no reason why not, unless the emulator has restrictions like having to have the whole app + disk image in active memory, no clue, I settled for 32mb for now)

So after booting, I fired up TheDraw and made a quick ANSI thingy, saved it as a .com, and saved that to the root (success!), then edited PLAY.BAT (the file which gets called by autoexec.bat on another virtual disk, the floppy, courtesy of Aemula so multi-disk, in a way ) to include my file, pushed save and crossed my fingers and pushed reset:

Finally, no crashes, rebooting, exactly 4096 bytes consumed by the created executable file, and full reading and writing on my 32mb disk image!

By the way, no clue where that a:\ drive thing is hiding, nor how to edit, nor is it really needed to edit it for this, it contains the basics of a boot disk. If you try to copy a file to it, it will not fail, nor does any file get added/changed. It has command.com, autoexec.bat, config.sys, etc, but nothing needs to be edited here unless we go play with CD-ROM .iso mounting.... but I have not the slightest idea where the app author keeps his 'banana's' or where I should put mine... It sounds strange, but this shi*t is banana's, I kid you not. If he is reading this, ... and he has room for another tester.. I'd be honored to help test things, and I'm most curious about this part, and the emm386 of course)

A quick scandisk.exe check to confirm disk is fine after writing, after previous seemingly successful but inevitable failures..

And a last peek at fdisk to see if that finally makes sense too (after having 60mb free on a seemingly 4mb big disk, which had actually about 32mb of data on it)

Note: FAT16, and it still mentions the 4MB size!

However, after having first added a normal MBR to the IMA and then cropping that off again, I can read/write error free and reported total disk space is at least correct, perhaps those 4mb are stored in the encrypted part of Aemula, perhaps only as display value, computed size, and usable spice, is as big as you make your .IMA file in WinImage....

Ok so I am more than happy to share the steps, from above you can, or should be able to deduct a lot of info (fat16 works, bootable .im1 does not work, aemula does that step here, the MBR needs to be correct for the app, or writing fails) so you can avoid the pitfalls and enjoy oceans of space, from a DOS point of view that is, of course.

Other discoveries/info:
-Tho bluetooth keyboards should(?) work, plugging in a usb keyboard to the camera connection kit sadly does not. Even tho iOS itself, mail, safari, etc, work fine with it (a cheap pc usb KB works fine, my 'old' iMac-G4 usb KB sadly does not, however, that one works great on my Android tablet, go figure)

-Attempting to use sys.com and/or format, obtained from 'other places' localy on the emu seems to indeed make the C: a bootable partition, however a reset of the emulator then causes it to hang, I did copy back this modded .im1 file but forgot to take a peek at it and accidentally 'dd' bit hacked the sense out of it thinking it was another file. Worth investigating what changes in the MBR

-Using the onscreen keyboard to draw ansi-art with TheDraw is a form of sadomasochism, if it floats your boat I can recommend it, for bonus points make it an animated ANSI and get ansi.sys to load!

-Windows 3.1 did not run (yet?) and deleting that attempt was the quickest way to regain half my drive space.

-Norton Commander doesn't run, garbled screen

-ZZT, the 80x25 text-only game, ran surprisingly slow, not playable. Graphic performance of the emulator outruns its plain text capabilities by miles

-Fast Tracker 2.0 doesn't run so far, exits because there is no mouse driver, I would loove some 8bit tracking action... perhaps in the future.

-There is no easy access/back-door solution here. The author plays by the rules, and the .IMA files I eventually got working does _not_ need to have its FAT16 table removed, I did however first have to write/save the IMA with it's MBR included, only to have to remove that bit again (up till the FAT16 table) else it won't work or behave unpredictable, something does need to be prepended to this cut IMA file to make it an .im1, of course, you'll find that bit in the app-included-bigger-than-1,4-im1's

-If you need a zip/unzip program, I use doszip now and it's pretty awsome, it more or less replaces the need for Norton Commander, I have not even scratched the surface of it yet, but then again, I began this day without Aemula on my iPad, so cut me some slack link: [URL="http://sourceforge.net/projects/doszip/"]sourceforge.net/projects/doszip/[/URL]

-I managed to compile gorilla.bas into a standalone executable from within the emulator, if anyone is in need of some banana throwing action (what is it with the banana's today?!) then do let me know!

-I could not have done this without the help of Menneisyys, a lot of coffee, and the strange urge to have Jill of the Jungle prancing around on my iPad.

-I think I had too much coffee today, so excuse the blah and see if you can filter the bits out of it,.. like.. make a fat16 image and such, include PLAY.BAT in its root, which must contain at least a 'emucfg /s cycles-per-ms 8000' of sorts, let me know if I can post files

04-03-2012, 06:30 PM
Originally Posted by spartaneye View Post
Just grabbed the new version of this from the app store, awesome to see Duke Nukem 2 added, anyone with the appropriate skills figure out if larger file sizes/iso images are mountable now?
Yes, I have bigger volumes working, any size you could normally want (FAT specs would say 4gb, more likely the memory / available storage on the iPad will be limiting before that). I have a 32mb image currently and for DOS emulation this goes a long way already

I attempted to post a full post with pictures about this yesterday, but this has yet to be approved/submitted, I guess it was not allowed or I did something wrong. I'm new here Eitherway, I am more than happy to share how to do this.

Last edited by Syntax Terror; 04-03-2012 at 06:35 PM.
04-03-2012, 08:33 PM
Really thanks to Menneisyys for your dedicated work.
However I failed to get it work no matter following the manual steps or script version (it seems everything running smoothly, no command error at least).
After running in AO it shows the error below:

Invalid drive specification
Bad command or file name

Anyone hit this issue?
I'm using AO version 1.3, is that this new version has blocked Menneisyys hack??
04-03-2012, 09:56 PM
Pls ignore me, it turns out I've a bad idosboot.dump file.
Menneisyys approach works perfectly :-D
Thanks again Menneisyys
04-03-2012, 10:34 PM
Oh Syntax Terror please share with us how to make .im1 > 1.44MB size, extremely eager to know
04-04-2012, 01:37 PM
Originally Posted by cmchu View Post
Oh Syntax Terror please share with us how to make .im1 > 1.44MB size, extremely eager to know
I will need a moment to sort my chaos into hopefully understandable instructions. My previous remark that any size is possible has also turned out incorrect. I seem to be hitting a 256mb limit... I'll post a how-to here asap! Here's a peek at a 256mb working boot :-) I'll write the howto according to the steps I did for that.
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04-04-2012, 02:53 PM
Originally Posted by Syntax Terror View Post
....I'll write the howto according to the steps I did for that.

how-to make and use bigger images:
(using DD and WinImage)

Grab one of the larger-than 1.4mb images off of the iPad, in this example I will use vinyl.im1, have also tried wolf3d and duke2, works with all of those.

- Save the first 32256 bytes of vinyl.im1 as original header, we'll need it later.
dd bs=32256 count=1 if=vinyl.im1 of=header.dump

- Crop the same amount off of the .im1 file, this will create a readable .ima file
dd bs=32256 skip=1 if=vinyl.im1 of=temp1.ima

- Open temp1.ima in WinImage and:

-Edit FAT image size: (menu: Image -> Change format -> Select custom image format) according to below values:

File system: FAT 12/16
Sectors per cluster: 8 (4096)
Total number of sectors: Any value up till 510912, this will determine the size, example values: 32768 for 16mb 65536 for 32mb, 255456 for 128mb, 510912 for 256mb, this seems biggest possible atm. As soon as you see Sectors per cluster go from 8 (4096) to anything else when you fill in a number, then it's too big.
FAT12/16 Root entries: 512
Media descriptor: 248
Sectors per Track: 63
Heads 16
Hidden sectors: 63
Physical Drive Number: 128

-Save this new image as temp2.ima

- Delete the content still in the image, and add your own content
in the root there must be a file named PLAY.BAT containing at least the following:
a:\emucfg.exe /s cycles-per-ms 6000
- Once your done filling it, (I advise using folders and keeping the files in the root to a minimum by the way), check the following:
Menu -> Edit -> Boot sector properties:
These should be on -> MS-Dos 6.22
(Oem string should then says: MSDOS5.0)

-Once this is done go to menu Image -> Export to an image with a MBR, save as temp3.IMA

-close winimage, check if last created .ima file has the wished size, for example, if you filled in 510912 sectors, then the file should be 256mb big. if so, you can go on, if not, run around screaming, calm down, then try again.

-discard the first 16384 bytes of the created .IMA, saving the rest:
dd bs=16384 skip=1 if=temp3.ima of=partition.dump

-prepend the 32256 bytes you cut off earlier to the file created above:
copy /b header.dump + partition.dump

-rename the header.dump (which now contains everything) to vinyl.im1...
The original file has to be renamed first then of course, so like this for example)
ren vinyl.im1 vinyl.org
ren header.dump vinyl.im1

-copy the file to your iPad, first deleting the original vinyl.im1 there before copying.

-start Aemula, browse to the disk image you modded, and launch!

Let me know how that works out, I'm seeing if multiple partitions of 256 is an option, I also would like to know more about mounting of ISO's, etc. Have fun!