This module houses a Z80 serial I/O (SIO/0) device (Z84C4008PEG or Z84C4010PEG) and is designed for use with the RCBus retro computers.

The Z80 SIO/0 provides two serial ports. Each port has the following clock source options:

• Bus clock CLK
• Bus clock CLK2
• On-board oscillator

The module provides support for Z80 mode 2 interrupts, with the IEI and IEO signals available on a two pin header for linking with flying cables. These signals can also be optionally connected to the RC2014 bus with jumpers.

Address selection is by jumper, allowing two of these modules to be included in a system.

Features

• Compatible with existing SIO firmware
• Tight address decoding
• Flexible input clock selection with jumpers
• Easy access to input and output signals on header pins
• Interrupt daisy chain signals can be jumpered to bus or use flying leads
• On-board clock source (option, not included in kit)
• Works with 40-pin, 60-pin and 80-pin backplanes
• Extra options when used with enhanced backplanes

Documentation

The documentation can be found by following the link below.

Compatibility

This module conforms to the RCBus specification v1.0 for RCBus-2014 enhanced 39-pin long modules.

The printed circuit board outline conforms to the RC2014 standard for full height modules.

The module is compatible with all RC2014 backplanes, all RCBus-2014 backplanes (RC2014 compatible including SC100 series) and all full RCBus 80-pin backplanes (including SC700 series). When used with 40-pin backplanes some of the features of this module are not available. The interrupt daisy chain can be implemented with Dupont cables if not supported by the backplane.

When used with a 40-pin backplane the pins in the second row are not connected. As a result the enhanced bus CLK2 signal is not available as a baud rate clock. Also, the enhanced bus signals RX2 and TX2 are not available for the second serial port to connect to other modules.

The RCBus specification includes RCBus-2014 (both RC2014 standard 40-pin bus and RC2014 enhanced 60-pin bus) and also the full 80-pin RCBus. The 80-pin RCBus provides support for advanced Z80 features, such as the interrupt daisy-chain, as well as support for other processor families.

The Kit

The kit contains everything you need to build the module, except solder, tools and cleaning materials. The Z80 SIO/0 supplied is rated at either 8MHz or 10MHz. To use the completed module you require a suitable Z80 CPU and memory module, a suitable backplane, a USB to serial adapter (5-volt power and 5-volt signals), a computer, and a terminal program (such as Tera Term).

If you have any doubts about sourcing a suitable USB to serial adapter, you might like to include this option with your kit.

Printed Circuit Board

The printed circuit board is available on its own here.

Related items

• SC112 - Modular backplane
• Components, spares, and accessories

Notes

• This product is supplied as a kit of parts that require assembly.
• It is your responsibility to pay any import duty or taxes charged by your home country.
• My products are made in accordance with the "designed for RC2014" labelling scheme.
• RC2014 is a trademark of RFC2795 Ltd.
• This product is designed for hobby use and is not suitable for industrial, commercial or safety-critical applications.