Games that require two disks

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Last seen: 2 years 10 months ago
Joined: Jan 16 2021 - 12:56
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Games that require two disks

I am attempting to create a disk for a game that requires two disks to play.  When loading the game into an emulator the disk shows that I need to insert the second disk.  When I go to create the disk for the apple II, the second disk is not read and no game is ever loaded.  Is there a trick to creating disks that will indicate that the second disk will be need to inserted and then also read?  When I insert the second disk, the game tells me to insert disk one so it has created a cycle that brings me to believe the game was copied correctly but the disk drive does not attempt to read the disk at all.

Last seen: 1 year 7 months ago
Joined: Mar 31 2020 - 19:55
Posts: 848
Are you using the DOS 3.3,

Are you using the DOS 3.3, ProDOS, or PASCAL file system?



In DOS 3.3, you can specify a volume number and scan the drives to dsee if a disk is inserted with it. IIRC, the defqault volume is 254. In ProDOS, you do the same, but for a volume label. In so doing, you want a function that returns 0 if the volume cannot be found, then suspend until user input. This is where you ask the user to insert a disk and press Return. 


In reading a Return keypress, the function runs again, and if it returns 1, it exits and you continue. 

Last seen: 1 year 7 months ago
Joined: Mar 31 2020 - 19:55
Posts: 848
P.S. I advise using ProDOS,

P.S. I advise using ProDOS, if you are writing your game in ASM, so that you can use the ProDOS MLI, which is far moree robust, and sophisticated than clunky methods of running DOS 3.3 routines from ASM. 


I forgot to mention that PASCAL volumes use labels, like ProDOS, but I haven't seen many people using USCD-P to write games, so I suspect that is more information than you require. 


If you are using BASIC, then you can use the standard DOS and ProDOS commands, but supply volume information. Remember though, that you need to supply the volume number when you INIT in DOS. The precise format is:




This is usually INIT HELLO V254

If you only use INIT HELLO, then the volume is 254 by default, but if you for example, want Volume 1 and 2, you do this for each side:



You can substitute 'HELLO' with any name, which becomes the first filename on the disk, containing DOS/BASIC memory, or whatever code is at present in the addresss space used by DOS/BASIC memory. The volume number is embedded into every sector, so you can determine the present volume in a variety of ways. In any event, while this should allow you to detect which disk is inserted into Dn (usually D1), it has some drawbacks, and in any case, ProDOS is better at handling this;  but ProDOS requires a 64K system. 


If you want to support < 64K systems such as a stock ][+ at 48K, then you musty use DOS 3.3. 


Again, without knowing your target, and knowing in what language you are writing it, this is the more reasonable information that I can offer. 


The volume number is something that most DOS commands that deal with loading or saving can check against, e.g. BLOAD FILENAME, D1, V2. Again, ProDOS makes all of this easier. 



Last seen: 4 months 4 weeks ago
Joined: Apr 26 2016 - 08:36
Posts: 572
Format your disk image

If you''re playing a game that's already written that requires a second disk then chances are that you'll need a DOS3.3 disk image.


If you're using Virtual II (again, a guess) and you'r eusing it's "Create disk image" button, it will create a disk image, yes, but you'll have to format it.

If the game requires DOS 3.3 then boot up an image of the DOS 3.3 system master and quit to BASIC, "insert" your second disk image into Drive 2 and simply type "INIT HELLO".


If you require a ProDOS image you'll need to format that as well, so boot up an image of the ProDOS user's disk (ProDOS 1.0.1 or 1.1.1 will do fine) and use the Disk's utility program to "Format" your disk image.


If you just create a disk image and do nothing to it,it will be just like any other blank diskette you take out of a box - it's useless unless formatted.



Last seen: 10 months 2 days ago
Joined: May 27 2009 - 01:37
Posts: 1002
DSK images won't contain

DSK images won't contain Volume number. It's up to the emulator to default to 254. WOZ and NIB images will have a Volume number.


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