|}
It is advised that the remaining bits of the I/O address are set to "1" to avoid conflict with other devices. The recommended I/O addressess are:
[{|{{Prettytable|width: 700px; font-size: 2em;}}|''I/O address''||''PPI Function''|-|&F4xx||Port A data|-|&F5xx||Port B data|-|&F6xx||Port C data|-|&F7xx||Control|-|} In the CPC+, the 8255 is integrated into the ASIC. The "emulation" is not complete and some functionality is not available. Please see the "Extra CPC+ documentation" for more information. * Mode 1 (Strobed Input/Output) and Mode 2 (Bi-Directional Bus), as far as I know, are not used by any program, Mode 0 (Basic Input/Output) is always used. === Port Usage === NOTE * If you are using the firmware, always return the operating modes and I/O state of the ports used to their settings below. The firmware expects the settings to be the same as given below and may operate incorrectly if they are not. === PPI Port A === Operating system settings: * I/O Mode 0,* Output NOTE: * For writing data to PSG all bits must be set to output,* for reading data from PSG all bits must be set to input. [Image:8255 ppi 1.jpg]]
= Resources ==