On CPC, the The printer is operated as follows: to send a byte, use port &EF00 by sending the value 3 times (1st: Bit7=0; 2nd: Bit7=1; 3rd: Bit7=0), with bit7 used to validate the byte. For this reason, only the 7 least significant bits were taken into account. On Plus machines, the 8th bit of the printer port is on bit3 of register 12 of the emulated CRTC. This bit must have "seemed" unused to Amstrad engineers. Unfortunately, they didn't know about the Overscan Bits.
== Data / Strobe ==
== General Specifications ==
*[https://en.wikipedia.org/wiki/ESC/P Epson Standard Code for Printers (ESC/P)] Wikipedia article
*[https://files.support.epson.com/pdf/general/escp2ref.pdf Epson ESC/P Reference Manual]
For (detailed) general information about Amstrad/Scheider printers, see:
* [[8bit Printer Ports]]
Amstrad Plus machines can handle 8bit data natively. The 8th bit of the printer port is on bit3 of register 12 of the emulated [[CRTC]].
This bit must have "seemed" unused to Amstrad engineers. Unfortunately, they didn't know about the Overscan Bits.
== KC Compact Printer Port ==