_handler: void interrupt handler(void)
  cs:02C2 50             push   ax                      The ISR saves AX...
  cs:02C3 53             push   bx
  cs:02C4 51             push   cx
  cs:02C5 52             push   dx
  cs:02C6 06             push   es
  cs:02C7 1E             push   ds
  cs:02C8 56             push   si
  cs:02C9 57             push   di
  cs:02CA 55             push   bp
  cs:02CB BD1956         mov    bp,5619
  cs:02CE 8EDD           mov    ds,bp
  cs:02D0 8BEC           mov    bp,sp
#BCBUG3#19:  Counter++;
  cs:02D2 66FF068C02     inc    dword ptr [028C]
#BCBUG3#20:  Output=Counter & ~7; }
  cs:02D7 66A18C02       mov    eax,[028C]              ...but uses EAX
  cs:02DB 6683E0F8       and    eax,FFF8
  cs:02DF 66A39002       mov    [_Output],eax
  cs:02E3 5D             pop    bp
  cs:02E4 5F             pop    di
  cs:02E5 5E             pop    si
  cs:02E6 1F             pop    ds
  cs:02E7 07             pop    es
  cs:02E8 5A             pop    dx
  cs:02E9 59             pop    cx
  cs:02EA 5B             pop    bx
  cs:02EB 58             pop    ax
  cs:02EC CF             iret