From: gids.rs@sasktel.net   
      
   > Several years ago I was dinking with a Laser 128, and later with the    
   > SimSystem IIe emulator which had a similar - it seems, string-hacked -    
   > firmware. I got to thinking about the occasional programs I'd try with    
   > the 128 or SimSystem IIe that would blow up.    
      
   I think you meant "tinkering", "dinking" is such a harsh word.  :)   
      
   > Sometimes, these were old file-cracked single-load games, which I was able    
   > to get to work by using the old System Master to load an Apple ][ ROM, and    
   > then run them. That didn't always work.    
      
   I don't think it is the ROM that is at fault.  More likely the use of illegal   
   opcodes which the IIe tries to execute.   
      
   > From what I understand, the hardware isn't quite enough like the Apple //e    
   > or //c, that a //e or //c ROM could be used unmodified to drive a Laser,    
   > or a Laser ROM to drive a //e or //c - but I suspect there isn't much    
   > difference. I came up with the idea that perhaps, since most if not all    
   > of the source to the parts of at least some versions of the //e and //c    
   > firmwares DO have the source published (excluding FPBASIC, which isn't    
   > really relevant to this apart of having to be brought in from a //e or //c    
   > ROM), a new ROM could be developed which is, for all intents and purposes    
   > as far as any program can tell, an Apple //e or //c ROM and should be able    
   > to run on a Laser 128 even those programs which usually crash.    
      
   Maybe I can save you some trouble.  The biggest reason it cannot work (Laser   
   ROM in a IIe/IIc) is the firmware calls.  The Laser has a third layer of   
   firmware.  From what I can tell, it engages a softswitch that switches in a   
   2nd layer of firmware under    
   the $C100.C7FF range apart from the regular firmware.  This won't work on a   
   IIe/IIc.   
   For the most part, the IIe/IIc ROM's should work in a Laser 128.   
      
   > That said - it's a matter of implementation, of course: it would need to    
   > be tweaked to get around those hardware (ROM-banking) differences. And    
   > I'm not really sure what-all those differences actually are.    
      
   It has been awhile so I am trying to remember off the top of my head.  But   
   what the Laser does is to one of the listings, either monitor listing or   
   applesoft listing, was to look up the keywords from the $C300 or $C800   
   firmware.  This won't work on a IIe/   
   IIc.   
   But  I don't see why a IIe ROM won't work in a Laser 128.   
      
    > I'd try to do even more if I were sure it wouldn't break other stuff (such    
   > as the ProDOS-8 clone check)...    
      
   I believe there is a program on the Franklin boot disk that shows how to   
   defeat the Prodos clone check.   
      
   I thought I was going to get this big speed boost with the Laser ROM in a   
   IIe.  At last, I gave up on it, thinking it was more trouble than it was worth.   
   The results I came up with is, I believe the IIe firmware is faster in the   
   IIe/IIc in some ways due to the constant softswitch flipping into the firmware   
   the Laser does, but the Laser may make up for it as it uses more look-up   
   tables and does fewer    
   calculations, but the IIe/IIc does not have the extra memory for look-up   
   tables.   
      
   Disassembling the Laser ROM did give me some insight to as why they were not   
   subject to Apple's lawsuits, though.  I recommend disassembling it for the   
   curiousity, if not anything else.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)