From owner-freebsd-current Thu Apr 25 10:10:06 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id KAA22452 for current-outgoing; Thu, 25 Apr 1996 10:10:06 -0700 (PDT) Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id KAA22414 for ; Thu, 25 Apr 1996 10:09:59 -0700 (PDT) Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.12/8.6.9) id CAA32034; Fri, 26 Apr 1996 02:52:49 +1000 Date: Fri, 26 Apr 1996 02:52:49 +1000 From: Bruce Evans Message-Id: <199604251652.CAA32034@godzilla.zeta.org.au> To: bde@zeta.org.au, lehey.pad@sni.de Subject: Re: request for a new "feature" as regards DDB Cc: current@freebsd.org Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >> Polling the keyboard is destructive too. It took me many hours over >> many months to learn how to poll the keyboard on XTs. Early attempts >> used the 8259 to poll for interrupts. This didn't work well because it >> changed the state of the 8259. AT keyboards are much easier. >Do we still need support for XT keyboards? :-) Lowbug polls the >keyboard, and I haven't had any problems with it. FreeBSD never supported them. My debugger does. I won't break it :-). >> And that you can read the counters. The counters for timer0-3 are >> always readable. Only the counters for periods >= 1 second in the RTC >> are readable. >We're really only talking about a 30 second (or whatever) timeout >here. The RTC counters would do just fine for that. Except they will be stopped when you're tracing resettodr() and any other time RTCSB_HALT happens to be set due to a bug. More importantly, they are can't be read without destroying the state of the (write-only) RTC index register. Bruce