RS232 Interface for the CPC by Schneider. Schneider is the german distributor for Amstrad CPC hardware (however, this interface seems to be Schneider's own invention, not an Amstrad product).
Note: 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.
Pictures
- The Schneider RS232 interface
Interface
Description
PCB top
PCB bottom
Front Plate
Label
Expansion Port Cable
Power Supply
I/O Ports
Default I/O addresses are F8E0h-F8EFh (though the interface can be jumpered to use different addresses).
F8E0h - Indirect Data Register F8E1h - General Purpose I/O Data Register (0=Low, 1=High) F8E2h - Interrupt Pending Register B (write 0=clear, 1=unchanged) ;\ F8E3h - Interrupt Pending Register A (write 0=clear, 1=unchanged) ; F8E4h - Interrupt in-Service Register B ; not used F8E5h - Interrupt in-Service Register A ; F8E6h - Interrupt Mask Register B (0=masked, 1=unmasked) ; F8E7h - Interrupt Mask Register A (0=masked, 1=unmasked) ;/ F8E8h - Indirect Index and Interrupt Vector Register F8E9h - Timers A and B Control Register ;\ F8EAh - Timer B Data Register ; not used F8EBh - Timer A Data Register ;/ F8ECh - USART Control Register F8EDh - Receiver Status Register F8EEh - Transmitter Status Register F8EFh - USART Data Register
For details on the registers, see Z80-STI.
Software
Supported by "Starwriter".
Similar (or identical?) Interface
The circuit is very similar (or possibly indentical) to the Tim Riemann's RS232 interface, both circuits are using a Z80 STI, both mapped to the same I/O port addresses. Whether or not the circuits are fully compatible with each other is unknown. Some small details might differ. For example, the clock source being passed to the Z80 STI chip could be different.
Manual (german)
Page 1 (cable / jumpers)
Page 2 (schematic)
Page 3 (z80-sti registers)
Page 4 (blank / footer)
