From: mutazilah@nospicedham.gmail.com   
      
   I have now added read functionality.   
      
   And I was able to reuse my existing assembler code.   
      
   So that's a great result.   
      
   But as per comments below, I did get two surprising   
   results attempting to get it to work, with a working   
   theory.   
      
   BFN. Paul.   
      
      
   static int readcomm(int port)   
   {   
       UART uart;   
       unsigned long old1;   
       unsigned long old2;   
       unsigned long intdesc1;   
       unsigned long intdesc2;   
       unsigned long intaddr;   
       int xch;   
       int intno = 4;   
       int a8259 = 0x20;   
       int imr = 0x21;   
       int id;   
       int ch;   
      
       uartInit(&uart);   
       uartAddress(&uart, 0x3f8);   
       PREADB(a8259); /* we don't use the result of this */   
       uartDisableInts(&uart);   
       /* IRQs 0-7 are at 0xb0 instead of 8 now */   
       /* we are using IRQ 4 for COM1 */   
       old1 = G_intloc[(intno + 0xb0) * 2];   
       old2 = G_intloc[(intno + 0xb0) * 2 + 1];   
       intaddr = (unsigned long)hltinthit;   
      
       /* we are interested in this interrupt */   
       xch = PREADB(imr);   
       xch &= ~(1 << (intno % 8));   
       PWRITEB(imr, xch);   
      
       uartEnableGPO2(&uart);   
      
       /* uartEnableModem(&uart); */   
       /* uartRaiseDTR(&uart); */   
       /* uartRaiseRTS(&uart); */   
       /* uartCTS(&uart); */   
       intdesc1 = (0x8 << 16) | (intaddr & 0xffff);   
       intdesc2 = (intaddr & 0xffff0000)   
                  | (1 << 15)   
                  | (0 << 13)   
                  | (0x0e << 8);   
       disable();   
       G_intloc[(intno + 0xb0) * 2] = intdesc1;   
       G_intloc[(intno + 0xb0) * 2 + 1] = intdesc2;   
       uartEnableRxRDY(&uart);   
       hltintgo();   
       /* if I immediately disable UART interrupts, I can no   
          longer read the old pending id of RxRDY.   
          If I read the pending ids, RxRDY just gets reasserted,   
          presumably because I haven't actually read the   
          character yet.   
          If I try reading the character, a new character may   
          come in and I'll miss it.   
          So the safest thing to do is just disable interrupts   
          and assume that RxRDY was hit, since that was the only   
          thing actually enabled, and I don't bother reading the   
          interrupt ids. */   
       G_intloc[(intno + 0xb0) * 2] = old1;   
       G_intloc[(intno + 0xb0) * 2 + 1] = old2;   
       uartDisableInts(&uart);   
       enable();   
       ch = uartRecCh(&uart);   
       PWRITEB(0x20, 0x20);   
       uartDisableGPO2(&uart);   
      
       xch = PREADB(imr);   
       xch |= (1 << (intno % 8));   
       PWRITEB(imr, xch);   
      
       uartReset(&uart);   
       uartTerm(&uart);   
      
       return (ch);   
   }   
      
   --- SoupGate-Win32 v1.05   
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