Schneider RS232 Interface
The original Schneider RS232 Interface was released around 1985. Two years later, in 1987, a software-compatible clone was released as DIY schematic in a German book (link). Even later, around 1996, a copy of that DIY schematic also circulated in the internet (link). The DIY port address, timings and handshake signals are exactly the same as in the original Schneider version - except that DCD (Data Carrier Detect) isn't implemented in the DIY version.
Default I/O addresses are F8E0h-F8EFh (though the interface can be jumpered to use different addresses).
F8E0h - Z80-STI Indirect Data Register F8E1h - Z80-STI General Purpose I/O Data Register F8E2h - Z80-STI Interrupt Pending Register B ;\ F8E3h - Z80-STI Interrupt Pending Register A ; F8E4h - Z80-STI Interrupt in-Service Register B ; not used F8E5h - Z80-STI Interrupt in-Service Register A ; F8E6h - Z80-STI Interrupt Mask Register B ; F8E7h - Z80-STI Interrupt Mask Register A ;/ F8E8h - Z80-STI Indirect Index and Interrupt Vector Register F8E9h - Z80-STI Timers A and B Control Register ;\ F8EAh - Z80-STI Timer B Data Register ; not used F8EBh - Z80-STI Timer A Data Register ;/ F8ECh - Z80-STI USART Control Register F8EDh - Z80-STI Receiver Status Register F8EEh - Z80-STI Transmitter Status Register F8EFh - Z80-STI USART Data Register
Aside from the above 16 directly addressable registers, there are 8 indirectly addressable ones. For details on the direct & indirect registers, see Z80-STI.
- Supported by "Starwriter".
- BASIC example (for the official version) is found in the Schneider RS232 manual (see below scans)
- ASM example (for the DIY version) is included with Tim Riemann's RS232 interface
The uncommon shape of the housing dates back to a Schneider BTX modul (which was being intended to be plugged into Schneider Television Sets). Apparently Schneider produced too many housings, and re-used them for the RS232 interface. Actually, a RS232 interface is very much the same as a BTX interface (the actual BTX modem must be rented separately from Deutsche Bundespost), so even the PCB may be (almost/exactly?) the same for both devices.