Last modified on 30 September 2010, at 15:00

Schneiderware Real Time Clock

Revision as of 15:00, 30 September 2010 by Nocash (Talk | contribs) (Article)

The Schneiderware Real Time Clock is a battery-backed RTC, 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.

I/O Ports

Address (default) Address (alternate) Usage
FBE2h BUGGED:FBE1h Schneiderware RTC index/control (W)
FBE3h BUGGED:FBE2h Schneiderware RTC data 4bit (W)
FBE4h BUGGED:FBE3h Schneiderware RTC data 4bit (R)

Note - The Schneiderware Real Time Clock is somewhat similar to the CPCI Real Time Clock released in a special issue of the same magazine, but not identical (the RTC chip has different pin-outs, and some of it's 4bit registers are working slightly different, the leap-year bits, for example). The I/O ports are also slightly different: The Schneiderware version has additional control bits in port FBE2h, and, for whatever reason, it splits data to two separate addresses (for FBE3h for writing, and FBE4h for reading), rather than mapping both to FBE3h.


Caution - The listing in the magazine (and the databox files) are bugged and won't work: The I/O addresses are wrong. Additionally, some function entrypoints seem to be accidently set to 0000h.

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).



  • Schneiderware #5 Echtzeituhr (Real Time Clock) (10/1986 pages 78-85, corrections on 12/1986 page 6 and 3/1987 page 9, 9/1987 page 9, ROM driver in 4/1987 page 29)