Difference between revisions of "CPCI 8bit Printer Mod"
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[[Category:Printers and printer ports]][[Category:DIY]] | [[Category:Printers and printer ports]][[Category:DIY]] | ||
| − | An [[8bit Printer Ports|8bit Printer Port]] DIY extension from | + | An [[8bit Printer Ports|8bit Printer Port]] DIY extension from German magazine [[CPC Schneider International]] (issue 12'85, page 64). |
| − | Connects Printer Bit7 to | + | Connects Printer Bit7 to Joystick 1 Select signal (joystick port pin8). |
| − | This solution isn't too | + | This solution isn't too recommended. Some drawbacks and problems are: |
* Joystick Select is an open-collector output, so HIGH levels may be unstable (this could be fixed by an additional pull-up resistor). | * Joystick Select is an open-collector output, so HIGH levels may be unstable (this could be fixed by an additional pull-up resistor). | ||
* Bit7 may tend to be HIGH by default, so printing normal text won't work with normal software that doesn't support the mod (the schematic includes a switch to disable the mod manually). | * Bit7 may tend to be HIGH by default, so printing normal text won't work with normal software that doesn't support the mod (the schematic includes a switch to disable the mod manually). | ||
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== Note == | == Note == | ||
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Some years later the same magazine (renamed to [[PC Amstrad International]], issue 8/9'91, page 69) released another 8bit printer mod: This newer (and better) solution uses PPI.Pin12 (same as the [[Happy Computer 8bit Printer Mod]]). | Some years later the same magazine (renamed to [[PC Amstrad International]], issue 8/9'91, page 69) released another 8bit printer mod: This newer (and better) solution uses PPI.Pin12 (same as the [[Happy Computer 8bit Printer Mod]]). | ||
Revision as of 13:26, 19 April 2021
An 8bit Printer Port DIY extension from German magazine CPC Schneider International (issue 12'85, page 64). Connects Printer Bit7 to Joystick 1 Select signal (joystick port pin8).
This solution isn't too recommended. Some drawbacks and problems are:
- Joystick Select is an open-collector output, so HIGH levels may be unstable (this could be fixed by an additional pull-up resistor).
- Bit7 may tend to be HIGH by default, so printing normal text won't work with normal software that doesn't support the mod (the schematic includes a switch to disable the mod manually).
The circuit can be connected internally to the mainboard, or externally to the joystick/printer port connectors.
Original Article
Note
Some years later the same magazine (renamed to PC Amstrad International, issue 8/9'91, page 69) released another 8bit printer mod: This newer (and better) solution uses PPI.Pin12 (same as the Happy Computer 8bit Printer Mod).
