SC715 is a Compact Flash module designed for the RCBus.

• SC715 – Assembly guide
• SC715 – Compatibility
• SC715 – Parts list
• SC715 – Printed circuit board
• SC715 – User guide
• Designing your RCBus computer
• SC700 series information
• SC700 series support

Downloads

• SC715, v1.0, Kit contents sheet (PDF)
• SC715, v1.0, Schematic (PDF)
• SC715, v1.0, PCB design files (OSHWLab)
• SC715, v1.0, Gerber files (ZIP)

Errata

Nothing known

Suppliers

Kits	Website	Ships from
Stephen C Cousins	Tindie	UK
PCBs	Website	Ships from
Stephen C Cousins	Tindie	UK
Assembled and Tested	Website	Ships from
Not available
Components
See parts list

Parts List

Reference	Qty	Component
PCB	1	SC715, v1.0, PCB
C1 to C3	3	Capacitor, ceramic, 100 nF
C4	1	Capacitor, electrolytic, 100 µF
LED1	1	LED, green, 3mm, angled
P1	1	Header, male, 2 row x 40 pin, angled
P2	1	Box header, 2 x 20 pin, straight *, or Header, male, 2 x 20 pin, straight * included in the kit
R1 to R3	3	Resistor, 4k7, 0.25W
R4	1	Resistor, 1k, 0.25W
Screw (for spacer)	3	Machine screw, 6mm, M3
Spacer	3	Spacer, 10mm, M3, nylon
U1	1	74HCT138
U2	1	74HCT32
U3	1	74HCT74
IC socket 16-pin U1	1	Socket, DIP, 16-pin
IC socket 14-pin U2 and U3	2	Socket, DIP, 14-pin
Adapter	1	Compact Flash adapter

Printed Circuit Board

Compatibility

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	Read	Write
0x10 to 0x17	CF card	CF card

Jumper options

Jumper	Function
none

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.

Notes

• 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.