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Last modified on 28 January 2010, at 15:23

Printer Port

Revision as of 15:23, 28 January 2010 by Nocash (Talk | contribs) (→‎KC Compact 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

Pinouts

Upgrade to 8bit data

KC Compact Printer Port

The Printer Port in the KC Compact is fully compatible with the CPCs Printer Port, and includes some additional features:

  • Port EFxxh is CIO Port A, by default configured as Output, with inverted polarity on bit7 (same as on CPC). However, CIO Port A could be reprogrammed by software (for example: making it an Input, or disabling the bit7 inversion)
  • The 8th Printer bit connects to Bit5 of PIO Port C (same as the Happy Computer 8bit Printer Port mod)
  • The "TEST" Feature of the KC Compact BIOS allows to boot the computer remotely via some kind of "network" connection, which connects to some of the CIO Port A signals