English Amiga Board


Go Back   English Amiga Board > Main > Retrogaming General Discussion

 
 
Thread Tools
Old 25 July 2001, 23:56   #1
andreas
Zone Friend
 
Join Date: Jun 2001
Location: Germany
Age: 43
Posts: 5,858
Send a message via ICQ to andreas Send a message via AIM to andreas
"Mixed-Mode" Amiga disks

Hi,

didn't know where to put this, for it's neither a request nor a problem with a specific game, anyway feel free to move it if you think it doesn't belong here.

Recently, I learnt to know something about a "floppy disk format" I've never known before, consisting of a mixture of the common formats "DOS" and "NDOS", apparently used in my Soldiers of Hell crack of Cadaver - Last Supper.

Well someone pointed me to that - is it true that this game came on a "mixed-mode" floppy? I don't remember anything like this. I only witnessed a huge size decrease when FILECOPYing the game files to a fresh disk (about 600k). This told me that I had better _not_ filecopy this game. Anyway, for me it looked like a "normal" AmigaDOS disk.
andreas is offline  
AdSense AdSense  
Old 26 July 2001, 21:16   #2
Twistin'Ghost
Give up the ghost
 
Join Date: Apr 2001
Location: U$A
Age: 26
Posts: 4,662
Actually, Codetapper has discussed this in a different thread (sorry I don't have it handy, but hopefully one of the thread-location fetishists will help you out here). But it is not really uncommon in games. I was just looking at a copy of European Championship '92 and disk 1 appeared to be DOS (although with no files) and disk 2 was NDOS.

I don't recommend filecopying any commercial games, btw. DMS on an Amiga or zipped adf's on the PC.
Twistin'Ghost is offline  
Old 26 July 2001, 21:39   #3
andreas
Zone Friend
 
Join Date: Jun 2001
Location: Germany
Age: 43
Posts: 5,858
Send a message via ICQ to andreas Send a message via AIM to andreas
Twistin', careful. I was just talking here about both DOS and NDOS on *ONE* disk
andreas is offline  
Old 26 July 2001, 23:34   #4
Akira
Registered User

Akira's Avatar
 
Join Date: May 2001
Location: New York
Posts: 18,304
Twistin's European Championship '92 example is just like what you say, Andreas. Teh disk shows up as DOS, but has no files inside. But it's raelly full of stuff! It just uses a small part of the disk as DOS to show up a dupe directory, or something.
Akira is offline  
Old 26 July 2001, 23:52   #5
TikTok
Registered User

TikTok's Avatar
 
Join Date: Jul 2001
Location: Malayasia
Age: 37
Posts: 657
Somewhat related...I think the coverdisks from ST/Amiga Format (when it was one mag) were dual formatted for the ST and the Amiga, as were several early games I believe (I remember Starglider 2 being mentioned).

And there are quite a few games that appear to be DOS, but then show no files at all under workbench. Jimmy Whites Snooker is one example IIRC.
TikTok is offline  
Old 28 July 2001, 20:07   #6
andreas
Zone Friend
 
Join Date: Jun 2001
Location: Germany
Age: 43
Posts: 5,858
Send a message via ICQ to andreas Send a message via AIM to andreas
@Akira

So complex? I'd rather think with EC '92, you're describing a plain AmigaDOS disk where the directory/file entries have just been made invisible (like BUDOKAN which I described in another (older) thread, the files are still there but inaccessible when you do a 'dir').
AFAICS, European Championship '92 is _not_ a disk that contains any NDOS part, which would be what I was talking about. It's actually a "manipulated" AmigaDOS disk (like the Budokan one), but it's a different thing to a disk whose structure is really a mixture of DOS and NDOS..
andreas is offline  
Old 28 July 2001, 22:52   #7
Akira
Registered User

Akira's Avatar
 
Join Date: May 2001
Location: New York
Posts: 18,304
Hmm.. could be that, but how can you test that it is that way really? I have many disks that act like that, and from what Codetapper said, I understood they only kept a small block of DOS to show up a fake directory.
Akira is offline  
Old 29 July 2001, 00:05   #8
andreas
Zone Friend
 
Join Date: Jun 2001
Location: Germany
Age: 43
Posts: 5,858
Send a message via ICQ to andreas Send a message via AIM to andreas
OK, let me give you an example: BUDOKAN.
Even after the "removal" of the entries so they aren't listed when doing a "dir", each and every block's first longword is one of "$00000002" (root block), "$00000008" (data block) or any similar stuff with special meaning (eg $00000010).

On the one hand, I define a real AmigaDOS disk as a disk which has a *straight* structure and 1760 blocks. NDOS disks (usually) have custom block size and/or number.
On the other hand, I define it as a disk which has a ROOT block on Block #880 and nowhere else. (Side-note: BOTH MUST have their BOOT block on Block #0.)
Take X-Copy: you can only list the directory of the disk if block 880 has the structure it expects (i.e. containing directory entries) -- you get an error message "not a dos disk!" if you try it with a NDOS disk.

Last edited by andreas; 29 July 2001 at 00:11.
andreas is offline  
Old 29 July 2001, 14:05   #9
Twistin'Ghost
Give up the ghost
 
Join Date: Apr 2001
Location: U$A
Age: 26
Posts: 4,662
And another possibility is that maybe dual-format disks are special formatted as partitions, like you can do with Zip disks (at least on the AMiga you can!)
Twistin'Ghost is offline  
Old 29 July 2001, 21:46   #10
Akira
Registered User

Akira's Avatar
 
Join Date: May 2001
Location: New York
Posts: 18,304
You can partition ZIPs on an Amiga? didn't know that. I should try and connect my zip drive to the miggy... will disks written on the Amiga be read by the PC too? this could be a useful transfer method.
Akira is offline  
Old 29 July 2001, 22:48   #11
Twistin'Ghost
Give up the ghost
 
Join Date: Apr 2001
Location: U$A
Age: 26
Posts: 4,662
OK, from what I remember back in the zip disk swapping days was that Amigas and Macs can format a dual partition disk. My Mac friend would give me a zip disk full of files and try to be a smart-ass by making two partitions: one Mac and the other PC. I was able to read both. But only the PC partition shows up on the PC.

So I returned the newly formatted zip disk to my Mac friend, but with three partitions: PC, Mac and Amiga. Needless to say, he couldn't read the Amiga partition.
Twistin'Ghost is offline  
Old 30 July 2001, 05:07   #12
Akira
Registered User

Akira's Avatar
 
Join Date: May 2001
Location: New York
Posts: 18,304
Haha, amazing! You will have to give me a few pointers so I can start using the zsip with my miggy. I have to buy an idefix interface soon, so taht will allow me to hook up the zip.
Akira is offline  
AdSense AdSense  
 


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Companion Disks "Complete Amiga C" from Cliff Ramshaw Dwyloc request.Apps 9 11 May 2014 03:25
Companion Disks "Complete Amiga C" by Cliff Ramshaw D4Ni3L3 request.Apps 14 24 April 2013 02:43
"Reminder "Lincs Amiga User Group aka "LAG" Meet Sat 5th of January 2013" rockape News 4 30 January 2013 01:06
"dual format" ST AMIGA cover disks NfernalNfluence New to Emulation or Amiga scene 27 31 July 2010 05:41
Companion Disks "Complete Amiga C" from Cliff Ramshaw Herpes Coders. General 5 28 March 2010 15:03

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +2. The time now is 00:32.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Page generated in 0.18668 seconds with 11 queries