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Schneiderware Pseudo ROM

210 bytes added, 07:20, 29 August 2014
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 - [[Upper ROM Bank Number|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)
'''Note''' - Port DFxxh is the standard [[Upper ROM Bank Number]] register, which is also used by [[AMSDOS]], for example. Reserved banks are 00h=Basic, and 07h=AMSDOS. Bank FFh (and XFh) can be also considred as reserved (as it's used by the "128K RAM detection" in CP/M+). Other bank numbers can be used by one (or more) Schneiderware Pseudo ROM board(s).
== Pictures ==
File:Schneiderware SRAM and EPROM Schematic.png|SRAM/EPROM Schematic
== Software ==
The magazine article contains three listings with examples on how to use the Pseudo ROM board, including a ROM version of the [[Schneiderware Real Time Clock]] driver.
== Scanned Article ==
* [[Media:Schneiderware 8 - Pseudo ROM.pdf|Schneiderware 8 - Pseudo ROM.pdf]] - SRAM and EPROM mapped as ROM - '''4/1987 page 26-34''', plus corrections in 5/1987 page 32-34