Changes
Created page with '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…'
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]]
== 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]]
