From: mutazilah@nospicedham.gmail.com   
      
   On Sunday, April 16, 2023 at 7:37:08 AM UTC+8, se...@nospicedham.conman.org   
   wrote:   
      
   > I replied once with some code, but it seems you didn't see it, so I'm    
   > replying again.   
      
   Sorry. I wasn't sure what to reply with, and I was still in   
   the process of debugging. Yours a different design,   
   and assembler-focused. I know this is an assembler group,   
   and I am indeed using assembler, but I'm trying to minimize it.   
   The required minimal assembler has already changed   
   numerous times to try to get this very basic functionality   
   working.   
      
   I'm not disputing that it wouldn't work or be better.   
      
   But I have a different design I am trying to get to work.   
   (and it should work - and the fact that it only half-works   
   is exactly what I want to see and understand).   
      
   > Why are you installing, then uninstalling, the interrupt handler for each    
   > character?   
      
   So that I can see an understandable sequence until I   
   am happy that the sequence is right.   
      
   I can potentially move that later. But I probably won't,   
   because the interrupt may be shared. And code   
   elsewhere would use the same assembler routine,   
   same interrupt number, same simple logic, and still work.   
      
   > And I think you are making this out to be more complicated that    
   > it should be.   
      
   It is more complicated for an assembler programmer, but   
   not more complicated for a (or at least, this) C programmer,   
   because almost all the logic is in C.   
      
   > As I wrote before, the interrupt handler for the UART can be    
   > as simple as:    
   >    
   > pause:    
   >    
   > hlt ; halt CPU    
   >    
   ...   
   > bne pause ; if not, keep waiting    
      
   And I can't move this code out into C, due to this requiring   
   the stack pointer isn't changed.   
      
   I don't wish to use inline assembler either - I want my   
   C code to be C90-compliant.   
      
   > You need to tell both the 8259 and the UART that the interrupt has been    
   > handled.    
      
   I believe my code does that.   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
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