That's true Mike. I stand corrected. The BUSY signal and the BUSY NOT signal connect directly to the 81C55 and, consequently, can be programmed by it to be directional: from the printer toward the Model T laptop (normal situation), or from Model T laptop toward the printer. Like you, I never tried programming the 81C55 to alter the signal direction of PC1 or PC2.
Keeper of the Primordial Bit (mother of all bits), -= Ron Wiesen =- -----Original Message----- From: M100 [mailto:[email protected]] On Behalf Of MikeS Sent: Monday, April 20, 2015 15:21 To: Model 100 Discussion Subject: Re: [M100] BlueM with DOS, serial ethernet adapter with M100 I must confess that I've never tried it, but the 81C55 datasheet seems to say that PC1 and PC2 are I/O pins, the direction being controlled by bits 2 and 3 of the C/S register. Am I missing something? m ----- Original Message ----- From: "Ron Wiesen" <[email protected]> To: "'Model 100 Discussion'" <[email protected]> Sent: Monday, April 20, 2015 11:06 AM Subject: Re: [M100] BlueM with DOS, serial ethernet adapter with M100 > All pins of the PRINTER port are > uni-directional. The signal direction of > two of them is from printer toward the Model T > laptop. > > Keeper of the Primordial Bit (born of the Big > Bit Bang), -= Ron Wiesen =- > > -----Original Message----- > From: M100 > [mailto:[email protected]] On > Behalf Of MikeS > Sent: Saturday, April 18, 2015 15:06 > To: Model 100 Discussion > Subject: Re: [M100] BlueM with DOS, serial > ethernet adapter with M100 > > ----- Original Message ----- > From: "Hiraghm" <[email protected]> > To: <[email protected]> > Sent: Saturday, April 18, 2015 3:14 AM > Subject: [M100] BlueM with DOS, serial ethernet > adapter with M100 > >> I wish the printer port was bi-directional... >> but I'm rambling now... > > Two pins are; why? > > BTW, re the BT & WiFi adapters, keep the > lack/presence of hardware handshaking in mind if > it's relevant to your application. > > m
