Printer Port

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The printer port supports parallel 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

General Specifications

For (detailed) general information about Amstrad/Scheider printers, see:

DMP4000 Mechanics.jpg


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

Aleste 520EX Printer Port

The Aleste 520EX is not compatible with the CPCs Printer Port (it's having other, non-printer related hardware mapped to EFXXh). Aside from the compatibility problem it's better than the CPCs port: Data is 8bit bi-directional.

Non-Printer Devices that connect to the Printer Port