rhealey@digibd.com (Rob Healey) (05/08/91)
Is there some sort of incestuous relationship betwixed /dev/par and /dev/ser? When ever I access /dev/par, either as the device or through lp subsystem, the DTR signal on ser goes down and stays down till I power cycle the modem?! Is this the DTR problem the 1.1 Amix release notes were talking about? Needless to say, fork()ing over my serial port by accessing the parallel printer device is most disturbing... As an aside, WHY do the two devices interact and is this quirk fixed in 2.0 like all the other annoying 1.1 problems? Ahh, the minor details, -Rob -- Rob Healey rhealey@digibd.com Digi International (DigiBoard) Eden Prairie, MN (612) 943-9020
jesup@cbmvax.commodore.com (Randell Jesup) (05/11/91)
In article <1991May07.174216.1325@digibd.com> rhealey@digibd.com (Rob Healey) writes: > As an aside, WHY do the two devices interact and is this quirk > fixed in 2.0 like all the other annoying 1.1 problems? Well, they do share some of the CIA resources for handling IO bits. I don't think DTR should move if the printer is in use, so it may have been an extra bit mistakenly written to the register. Let's see... PA7 on cia b is DTR, PA3-6 are other serial control lines, PA2 is printer SEL, PA1 is printer POUT, and PA0 is printer BUSY. cia a has the printer data lines in PBx, and drdy and ack hooked up to PC and F. -- Randell Jesup, Keeper of AmigaDos, Commodore Engineering. {uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com BIX: rjesup Disclaimer: Nothing I say is anything other than my personal opinion. Thus spake the Master Ninjei: "To program a million-line operating system is easy, to change a man's temperament is more difficult." (From "The Zen of Programming") ;-)
ford@amix.commodore.com (Mike "Ford" Ditto) (05/14/91)
rhealey@digibd.com (Rob Healey) writes: > > Is there some sort of incestuous relationship betwixed /dev/par and > /dev/ser? There's not supposed to be, but there was a bug... > As an aside, WHY do the two devices interact and is this quirk > fixed in 2.0 like all the other annoying 1.1 problems? As Randell speculated, some extra bits were being written to a CIA register. As I recall, the whole byte was being written when only 3 bits needed to be changed. -=] Ford [=- "Look over there!... A dry ice (In Real Life: Mike Ditto) factory -- a good place to get ford@amix.commodore.com some thinking done." uunet!cbmvax!ditto - Talking Heads, "Cities" ford@kenobi.commodore.com