wnp@dcs.UUCP (Wolf N. Paul) (11/30/88)
(I have cross-posted this follow-up to comp.unix.microport, as it is more appropriate and more likely to find expert readers there.) In article <112@cosi.UUCP> bill@cosi.UUCP (Bill Michaelson) writes: > >Another annoying problem (unrelated to Merge): I have four serial ports >on my '386 machine. As is typical with many AT clones, the ports may >each be configured to one of four addresses (called COM1-COM4 in the MS- >DOS world), and one of two interrupt levels (IRQ2 and 3). The device >drivers that come with the system apparently don't allow serial ports to >share interrupt levels. It's puzzling because the documentation indi- >cates that multiport boards use single interrupt levels. A command >called ttypatch is used to configure the drivers. As it was explained to me, the problem is the following: The driver will support multiple ports (at different addresses) using the same interrupt IF THEY ARE ON THE SAME BOARD. In other words, two ports may share an interrupt, two boards may not. Unfortunately, standard AT and XT style com boards, which support two ports per board, are set up to use two interrupts per board, and both of these may be shared by up to two boards. Thus, it is set up the reverse from what the Uport serial driver expects. The Uport release notes explicitly refer to "Digiboard and similar" boards; I didn't see that reference until after I got frustrated myself with the same problem. -- Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101 UUCP: killer!dcs!wnp ESL: 62832882 DOMAIN: dcs!wnp@killer.dallas.tx.us TLX: 910-380-0585 EES PLANO UD