SC715 – RCBus Compact Flash Module

SC715 is a Compact Flash module designed for the RCBus.



Nothing known


KitsWebsiteShips from
Stephen C CousinsTindieUK
PCBsWebsiteShips from
Stephen C CousinsTindieUK
Assembled and TestedWebsiteShips from
Not available
See parts list

Parts List

PCB1SC715, v1.0, PCB
C1 to C33Capacitor, ceramic, 100 nF
C41Capacitor, electrolytic, 100 µF
LED11LED, green, 3mm, angled
P11Header, male, 2 row x 40 pin, angled
P21Box header, 2 x 20 pin, straight *, or
Header, male, 2 x 20 pin, straight
* included in the kit
R1 to R33Resistor, 4k7, 0.25W
R41Resistor, 1k, 0.25W
Screw (for spacer)3Machine screw, 6mm, M3
Spacer3Spacer, 10mm, M3, nylon
IC socket 16-pin
1Socket, DIP, 16-pin
IC socket 14-pin
U2 and U3
2Socket, DIP, 14-pin
Adapter1Compact Flash adapter

Printed Circuit Board


This module conforms to the RCBus specification v1.0 for RCBus-2014 and RCBus-Z80.

User Guide

SC715 is a Compact Flash Card interface for RCBus. It uses Tadeusz Pycio’s design to correct the timing between the Z80 CPU and the Compact Flash card.

The module is designed to be mounted either horizontally at the end of a modular backplane, as illustrated below.

Alternatively, it can be mounted vertically.

The LED indicates Compact Flash card activity, both read or write.

The Compact Flash card capacity is not critical, but it should be noted that plain CP/M 2.2 can only access the first 128MB of the card. RomWBW can access up to 2GB. Any space above these limits can not be accessed by the retro computer. High capacity, more modern, high speed cards are best avoided as they are more likely to cause noise issues on the bus.

Input/output port functions
I/O Address ReadWrite
0x10 to 0x17CF cardCF card
Jumper options

Assembly Guide

Below is the suggested order of assembly. A general guide to assembling circuit boards can be found here.

  1. Resistors R1 to R4
    These can be fitted either way around
  2. Decoupling capacitors C1, C2 and C3
    These can be fitted either way around
  3. Sockets for U1, U2 and U3
    Fit such that the notch in the socket matches the curve in the outline on the PCB silkscreen
  4. Bus header P1
    Make sure the pins are parallel to the PCB so that the board is vertical when it is fitted into a backplane socket
  5. Light emitting diode LED1
    The angled LEDs in the kit only fit one way around, but standard LEDs need to have the short lead in the hole marked with a flat line, as described here
  6. Capacitor C4
    This must be fitted the correct way around, as described here
  7. Box header P2
    The kit includes a box header, but straight header pins could be used instead. Ensure the orientation matches the outline on the PCB’s silkscreen.
  8. Insert the integrated circuits into their sockets
    Make sure the notch in the component is at the end indicated by the notch in the socket and the curve on the PCB silkscreen
  9. Fit the nylon spacers in the mounting holes
    The two by the Compact Flash socket are designed to be fitted on the solder side of the PCB so that the module is supported when connected horizontally to a modular backplane, such as SC701, SC702, SC709 or SC710. They are not needed if the module is mounted vertically.


  • This product is designed for hobby use and is not suitable for industrial, commercial, or safety-critical applications.
  • The product contains small parts and is not suitable for young children.
  • The Compact Flash interface circuit has been designed by Tadeusz Pycio and reproduced with his permission.

Homebrew 8-bit retro computing