2,093 bytes added,
19:04, 30 September 2010 The [[Schneiderware Pseudo ROM]] is a expansion "ROM" board, with 16K EPROM (read-only) and 16K battery-backed SRAM (read/write-able), published by german magazine [[CPC Schneider International]] as part of their [[Schneiderware]] DIY series. The plain PCB, or the fully assembled board were also available via mail-order.
The [[ECB Bus]] connector of the board is intended to be plugged into the [[Schneiderware Basisplatine]], but it could be also wired directly to the CPCs Expansion Port.
Databoxes: '''UHR8000''' RTC-RAM-driver in 10-1986 (hex listing, plus [[Hisoft Devpac]] source code) (caution this version uses incorrect I/O addresses FBE1-FBE3), '''UHRC000X''' RTC-ROM-driver in 4-1987 (this version uses correct I/O addresses FBE2-FBE4). Uni-PIO examples in 12-1986 (=only a few basic lines). There seem to be no Centronics and V/24 drivers included in databoxes.
== Article ==
* [[Schneiderware Pseudo ROM|Schneiderware #8 Pseudo ROM (SRAM and EPROM mapped as ROM)]] (4/1987 pages 26-34, plus corrections in 5/1987 pages 32-34)
== I/O Ports ==
{|{{Prettytable|width: 700px; font-size: 2em;}}
|Address (default) || Address (alternate) || Usage
|-
|DFxxh || N/A || Schneiderware RAM/EPROM - Expansion ROM bank number (W)<br>Battery-backed SRAM and/or EPROM are selected 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 during writing.
|-
|}
== Pictures ==
<gallery>
File:Schneiderware SRAM and EPROM Schematic.png|SRAM/EPROM Schematic
</gallery>