Changes

The CPC [[Printer Port]] has only 7bit 7 bit data. Which is okay sufficient for english 7bit English 7 bit ASCII character sets, but not enough for 8bit 8 bit character sets. Also, printing bitmap graphics usually requires 8bit 8 bit data (though Amstrads own printers are probably working usually can also print 7 pixels columns combined with 7bita reduced line-feed rate). Amstrad's DMP1 works perfectly with 7 bit, but Amstrad's later DMP2000/DMP2160 include a few functions that won't work on 7 bit ports - so even the official CPC printers aren't fully compatible with the CPC printer port.

* There's a software solution though, proposed by [[Connector:Printer portAmstrad Computer User]]using a replacement driver (only for printers accepting EPSON control codes).

== Internal 8bit 8 bit Printer Ports/Mods ==

=== Happy Computer 8bit 8 bit Printer Port upgrade (DIY) ===A good method to upgrade to full 8bit 8 bit has been described in the german magazine "[[Happy Computer (Schneider Sonderheft )]] 2/85 and 4/86":

Sharing that pin will cause no problems (as long as you do not attempt to send data to the tape drive and to printer at the same time). Of course, you will also have to customize your software, or BIOS ROM, or the BIOS jump vectors in RAM, in order to take advantage of the modification. In contrast, this DIY is supported by [[FutureOS]].

The same way to upgrade the === CPC printer port to 8bit is also described in the CPC Amstrad Schneider International issue - 8/9'91.bit Printer Port Mod ===

=== DIY from [[CPC Schneider International]] (issue 12'85, page 64), this solution uses joystick port pin 8 (or (keyboard?) pin 2, unclear?).* For details see: [[CPCI 8bit Printer Port in KC Compact ===Mod]]

The [[KC Compact]] uses the Bit5 of [[8255|PPI]] Port C as 8th printer === PC Amstrad International - 8 bit (this is same as the Happy Computer mod, see above).Printer Port Mod ===

=== DIY from [[PC Amstrad International]] (issue 8/9'91, page 69-70), this solution uses PPI.Pin12 (same as the [[Happy Computer 8bit Printer Port in Aleste 520EX ===Mod]]).

The [[Aleste 520EX]] includes an 8bit printer port, using PSG Ext === 8 bit Printer Port B for data (which does not exist on the CPC), and PPI port C, Bit 4 for strobe (which would be Tape Motor in CPC). The Aleste doesn't have the normal CPC-style [[Printer Port]] at Port EFXXh.KC Compact ===

The [[KC Compact]] uses the bit 5 of [[8255|PPI]] Port C as 8th printer bit (this is same as the Happy Computer mod, see above). Although the 8th bit is a built-in feature, the KC Compact Firmware doesn't support it. But it's supported by [[FutureOS]]. === 8 bit Printer Port in Aleste 520EX === The [[Aleste 520EX]] includes an 8bit printer port, using PSG Ext Port B for data (which does not exist on the CPC), and PPI port C, Bit 4 for strobe (which would be Tape Motor in CPC). The Aleste doesn't have the normal CPC-style [[Printer Port]] at Port EFXXh. The BIOS functions are patched accordingly; including for supporting the 8th bit (unlike the CPC Plus and KC Compact, which do not support the 8th bit in BIOS functions). === 8 bit Printer Port in CPC Plus ===In the CPC Plus, Bit 3 of [[CRTC]] Register 0Ch can be used as eighth printer bit. For compatibility to normal CPCs, this feature can be disabled by removing the 10kOhm 10 kOhm resistor R30 on the mainboard (aka R130 in the schematic). See [[LK Links]] for more info. Although the 8th bit is a built-in feature, the CPC Plus Firmware doesn't support it. However the 8 bit printer port of the CPC Plus is supported by [[FutureOS]].

* [[8bit Printer Port (Paul Bauriedl)]] (DIY) - connects to Printer Port (splits port EFxxh to 2x4bit2 x 4 bit)* [[BrunWord|BrunWord's Eight Bit Status port]] - connects to Printer Port (splits port EFxxh to whatever, details are unknown)* [[CPCI 8bit Printer Mod]] (DIY) - connects bit 7 to Joystick_1_Select signal (can be connected internally or externally)

* Communicator 104 8 bit Printer Port (KDS ElectronicsPride Utilities) (1992) Reportedly: "Serial and Parallel interface" (or, actually, [[Mini-Max ModemPride Utilities 8bit Printer Port|details]])* 8bit 8 bit Printer Port with Dual RS232 (KDS Electronics) (this may be same as above[[Timatic Systems]])* 8bit 8 bit Printer Port with 16 bit I/O port (Pride Utilities[[HoneySoft]]) (see [[Pride Utilities 8bit Printer PortMedia:Amstrad Computer User8509037.jpg|detailsadvert]])* Other external printer-related hardware (though not 8bit related): * Centronics to serial 8-pin DIN Adaptor for "Gabriele 9009" daisy-wheel printer from Triumph-Adler (DIY, [[CPC Schneider International]] 12-1985, pages 88, 89)* KDS Printer Port with Dual RS232 T Switch ([[Timatic SystemsKDS]])- allows to connect 2 printers, the desired printer can be selected via software  == Software solution (only for printers that support EPSON control codes) == Written by J. G. Gribbs and published in [[Amstrad Computer User]] magazine in July of 1991. <gallery>image:ACU9107-056.jpgimage:ACU9107-057.jpg </gallery>

== Unknown Solutions See also ==

* CPCI [[Connector:Printer port|Printer Port Pin- german magazine "CPC Schneider International 12/1985" - contains something about 8th bit - unknown if this is an internal mod, or external adapter or whatever? Outs]]* CPCI - german magazine "CPC [[Amstrad International issue 8/9'91" - said to contain the same solution as Happy Computer.Schneider Printer Support for 7bit Printer Ports]]

[[Category:HardwarePrinters and printer ports]] [[Category:DIY]]