From: me@yyzkevin.com   
      
   Raptor Call of the Shadows works good with my TSR but crashes without,   I had   
   tested that one at the start given it had been recommended to me as a problem   
   game to test on my PCMCIA project.   
      
   While I understand the existence of the differences of  microchannel vs ISA,     
   and those  require significant differences when designing hardware,   but  I   
   had always thought  from the perspective of a  DOS program that is not   
   attempting to do anything    
   special,   interactions with i/o, memory, interrupts, DMA   should pretty much   
   be no different.     
      
   I would say this is certainly true for i/o  access,  from the perspective of a   
   dos program there is nothing different here.  The speed could vary if you were   
   attempting to use it for timing delays (reading ports etc) but on ISA the bus   
   speed can vary    
   wildly  from system to system,  you can have  unfriendly  neighbors  making   
   heavy use of iochrdy etc,  so varied speed was something to be expected.   
      
   In the case of interrupts I would also say it is the same between the two   
   systems.  You just hook the interrupt as usual,  and you get called when the   
   interrupt is fired,  and you clear/send the EOI to the PIC controllers at the   
   end of your routine.  If    
   you are going to be sharing an interrupt this is a bit more special case,     
   but this is seen outside of microchannel and if you are doing thing properly   
   you would check with your hardware in your routine to see if you had requested   
   the  interrupt, and if    
   not  call the routine that you had replaced when you hooked in... more or   
   less.  the programs that fail on MCA here (so far at least) are simply because   
   they were  perhaps a bit sloppy,   and not  clearing their request for an   
   interrupt during their    
   handler,  which yes on ISA they can get away with because nothing can happen.   
   (again this exists in pcmcia world too).   
      
   On the topic of DMA,   not that I am so familiar with the others, but this I   
   would be least familiar with.  but from the perspective of simple dos software   
   attempting to setup simple transfer,   I expect to configure the DMA   
   controller and page register    
   as usual, and that is it the hardware has to deal with the rest?   i still   
   have some reading to do here.   
      
      
   On Sunday, 2 July 2023 at 08:15:11 UTC-4, Ryan Alswede wrote:   
   > > on the topic of duke3d, I have not been able to get any version to crash   
   including the one listed above.   
   > The older version would just not make sound. Did not crash.    
   >    
   > See if you can play Raptor Call of the Shadows then. It talks about PS/2 in   
   the readme so there maybe hope. Adlib was the only thing it would do for FX   
   sounds.    
   >    
   > DMA is a whole another animal. You have the following to deal with in MCA.   
   These settings were interesting to play with when I was working with the   
   Ultimedia 7-6 card driver.    
   >    
   > -Adapters can do burst-mode where it can have complete control of the DMA   
   channel for up to 12mSec.    
   >    
   > -MicroChannel Fairness feature, when 'Fairness' is disabled, the adapter   
   will compete for every arbitration phase and will obtain more than its fair   
   share of channel usage but allows for smoother audio play back."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)