Silicon Sam wrote:
Sean Fahey wrote:All Imagewriters are serial. The Apple DMP and SilentType printers that preceeded it were parallel.The Silentype was serial too, sorta, but it used a special interface card in the ][. Even got it's power from the card. I have one in the next room, minus the card of course.
Actually, the Silentype was neither a serial standard nor a parallel standard--it used a direct control interface comparable to the way the Disk ][ drive was controlled. Its two stepper motors (paper advance and carriage) were controlled by software (firmware) running on the Apple's 6502, which also sent the signals (in "parallel") to heat the vertical row of dots in the thermal print head. So the Silentype was about as "dumb" as a printer can be, with the Apple responsible for controlling all its motions and converting characters to graphic 5x7 images using font tables. -michael New, faster SUDOKU v2.0 solver for Apple II's! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."