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Atari 8-bit Software Preservation Initiative


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#726 DjayBee OFFLINE  

DjayBee

    Chopper Commander

  • 224 posts
  • Location:Stuttgart, Germany

Posted Wed Oct 25, 2017 12:18 PM

 

It's time for an updated torrent. As always, thanks to everyone that contributed!

 

Some findings regarding images:

  • Diskey (1982)(Adventure International)(US)[!]
    needs BASIC
  • Strip Poker (1983)(Artworx)(US)[a]
    needs BASIC
  • Rescue on Fractalus! v4.1 (1985)(Epyx)(US)[!]
    does not run because the code expects error 139 (device-NAK) for the bad sector but in reality it has a CRC error which leads to error 144 (device done). This is really odd.
  • Koronis Rift (1985)(Epyx)(US)[!]
    different 3.1 version 51022d than the removed image 51022p which was part of the torent before. They differ in lots of code ...
    ... and v3.1d's protection is identical to v1.1 and v3.0, but differs from v3.1p (which is similar to Activision's releases of Lucas Arts games). Perhaps v3.1p actually was released by Activision.
    You might re-add the former version as an alternative.


#727 ijor OFFLINE  

ijor

    Stargunner

  • 1,924 posts

Posted Fri Oct 27, 2017 9:31 PM

 

Rescue on Fractalus! v4.1 (1985)(Epyx)(US)[!] does not run because the code expects error 139 (device-NAK) for the bad sector but in reality it has a CRC error which leads to error 144 (device done). This is really odd.

 

I'm out of home for a few days and can't access my notes. But IIRC, it's a bug in that particular version of the game (that seems to be fixed in later versions), and it requires an 810 and/or Altirra full drive emulation.



#728 ijor OFFLINE  

ijor

    Stargunner

  • 1,924 posts

Posted Tue Oct 31, 2017 6:59 PM

Now I can give a better answer ...

 

Rescue on Fractalus! v4.1 (1985)(Epyx)(US)[!]
does not run because the code expects error 139 (device-NAK) for the bad sector but in reality it has a CRC error which leads to error 144 (device done). This is really odd.

 

Koronis Rift (1985)(Epyx)(US)[!]
different 3.1 version 51022d than the removed image 51022p which was part of the torent before. They differ in lots of code ...
... and v3.1d's protection is identical to v1.1 and v3.0, but differs from v3.1p (which is similar to Activision's releases of Lucas Arts games). Perhaps v3.1p actually was released by Activision. You might re-add the former version as an alternative.

 

As I commented in my previous post, that version of Rescue on Fractalus has a buggy loader that provokes NAKs. It requires full 1050 drive emulation to run under Altirra.

 

The image of Koronis Rift in the previous torrent was missing a sector on track 40. And yes, I agree, that old image looks like an Activision release.



#729 phaeron OFFLINE  

phaeron

    River Patroller

  • 2,281 posts
  • Location:USA

Posted Tue Oct 31, 2017 7:57 PM

Here's what's going on with Fractalus' loader:

 

fractalus-bug.png

 

When it sees the error code from the drive, it immediately attempts to issue another disk read at the next vertical blank without waiting for the data frame from the previous read to complete. The drive itself doesn't send a NAK; it's still busy sending the data frame and can't respond to the new command frame, which then causes SIO to return a NAK because it interprets random data on the SIO bus as an invalid completion code. Almost all disk drives that I know of are unable to stop a data frame for a new command, though I think there was at least one drive that could (XF551? Indus GT?). Altirra's standard disk emulation also interrupts transfers immediately on a new command, thus the failure. But overlapping disk commands like this is bad ju-ju, and another example of how broken the Fractalus loader is.

 



#730 dukdukgoos OFFLINE  

dukdukgoos

    Combat Commando

  • 6 posts

Posted Tue Nov 21, 2017 2:42 PM

At some point around 2017-04-30 the torrents dropped all the "OS ROM" files... why was that? Couldn't find anything explaining in post history...



#731 Mclaneinc OFFLINE  

Mclaneinc

    Quadrunner

  • 5,010 posts
  • Location:Northolt, UK

Posted Wed Nov 22, 2017 4:04 AM

I'd guess copyright fears or warning..



#732 Farb OFFLINE  

Farb

    Moonsweeper

  • Topic Starter
  • 493 posts
  • Location:Frankfurt, Germany

Posted Yesterday, 12:28 AM

At some point around 2017-04-30 the torrents dropped all the "OS ROM" files... why was that? Couldn't find anything explaining in post history...

 

Probably a bug in the torrent generation script. I will have to check.






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