Date: Mon, 03 Nov 1997 11:40:37 +1030 From: Mike Smith <mike@smith.net.au> To: "Jamil J. Weatherbee" <jamil@trojanhorse.ml.org> Cc: hackers@FreeBSD.ORG Subject: Re: 7400 gates effected by probe routine Message-ID: <199711030110.LAA00736@word.smith.net.au> In-Reply-To: Your message of "Sat, 01 Nov 1997 23:29:56 -0800." <Pine.BSF.3.96.971101231708.2591B-100000@trojanhorse.ml.org>
next in thread | previous in thread | raw e-mail | index | archive | help
> > Not really, no, unless MODE reads != 0xff. The 8255 isn't what you'd > > describe as the most sophisticated bit of hardware. I'd still > > recommend looking at the driver as having to address the hardware on > > the other side of the card, rather than the card itself. > > I wish I had some hardware sophisticated enough for that! I just can't > see how you'd have anything that sophisticated unless you were > implementing some kind of bus with the thing, which for a card that > operates in MODE0 would be kinda cludgy, since MODE1 or 2? provides some > bi-directional features with port c as the status port. What I mean is that if your application has input signals, you can look for a typical configuration of those signals, or if your card is being used for output then you can remode the 8255 and write some sensible test values and read them back. This is only possible if you know what is connected to the card. mike
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199711030110.LAA00736>