Printer Port

The printer port supports one-directional 7bit data, strobe, and busy signals.

Data / Strobe

Port EFXX - Printer Port Output 74LS273 (7bit Data and Strobe) (W)

 Bit 0-6  Printer Data (7bit)      (0=Low, 1=High)
 Bit 7    Printer Strobe           (0=High, 1=Low)

Busy (PIO.PortB.Bit6)

Port F5XX PIO Port B

 Bit 0     VSYNC    CRTC Vsync flag (1=VSYNC active)
 Bit 1-3   LK1-3    Distributor Code (see below)
 Bit 4     LK4      Desired Screen Refresh Rate (0=60Hz, 1=50Hz) (see below)
 Bit 5     /EXP     External Input (used for external hardware only)
 Bit 6     BUSY     Printer Busy flag (1=Busy, 0=Ready)
 Bit 7     RD DATA  Tape Data Input

Upgrade to 8bit data

• 8bit Printer Ports