jimx@ihlpa.ATT.COM (Harris) (03/01/88)
I have three devices that must use the same two COM ports. The machine I am using is a Compaq 386, the 16 MHz version. There is one COM port on the machine, plus four others on an AST Async Cluster Adapter. This card can give me ports 1-4 or 3-6 (on the card). Switches allow me to select between several address locations, but not to map two channels to the same address. The voice card has dip switches that select either COM1 or 2. The touch screen documentation also indicates that it requires either COM1 or 2. AND, the version of Windows I have expects that a mouse will be on COM1 or 2. Whoo boy. I would like to share an interrupt between the mouse and the touch screen, since they are not likely to generate interrupts at the same time. But, I am new to this sort of thing, and don't know how to go about this. How do I get them both on COM1 (or 2)? I can see a chain of interrupt handlers, that check if their device generated the interrupt, but how does the hardware raise the same IRQ? Is it as simple as attaching the mouse to the machine's COM port and the touchscreen to the expansion card, at the same COM port? Then I could see the interrupt handler mediating between them. Any help, or references to sources of help would be appreciated. Thanks in advance. - Jim Harris ihlpa!jimx *** Any opinions expressed are strictly my own, and do not necessarily reflect those of anyone or anything else. ***