Changes
/* I/O Ports */
|Address (default) || Address (alternate) || Usage
|-
|DFxxh || N/A || Schneiderware RAM/EPROM - Expansion ROM bank number (W)<br>RAM Battery-backed SRAM and/or EPROM is are selected (and mapped to C000h..FFFFh) when the bank-number matches the jumper-selected values; the memory is then mapped to C000h..FFFFh (in case of READing one must also enable upper ROM via Gate Array). The bank number decoding is a bit strange:
* EPROM/Read bank: All 8 bits decoded (bank 00h..FFh)
* SRAM/Read bank: Only lower 4 bits decoded (bank X0h..XFh)
* SRAM/Write bank: Only lower 4 bits decoded (bank X0h..XFh)
The SRAM/Write mode doesn't disable the internal RAM in the CPC, so writes are going both to SRAM and normal RAM at C000-FFFF, that no matter if upper ROM is enabled/disabled via Gate Array; the author recommended to map VRAM to 4000-7FFF via CRTC registers, in order to prevent video dirt displayed on monitorduring writing.
|-
|F8E0h || F8F0h || Schneiderware Centronics 8255 PPI Port A (data)
