Table of Contents

Dual SD Card



The Dual SD Card board contains two Secure Digital card sockets and interfaces to the ECB bus, meaning it adds SD card storage to several ECB computer systems: SBC v1 & v2, SBC-188, and mini-M68k. (Zeta also?)

The interface is more complete than that on the N8 home computer, in that hot-swapping is better supported with full “card detect” features, as well as implementation of the “write protect” switch on all SD cards. Under software control, an interrupt may be generated whenever a card is inserted or removed. Write protection is purely a software feature of SD cards, but this is the first interface to provide the driver software a status indication of the position of the Lock / WriteProtect switch on each card.

The pad for soldering the SD card socket is designed to accommodate as many varied SD sockets as possible, and special jumpering is used to connect the proper Card Detect and Write Protect pads to the register inputs. The 'doc' directory contains detailed information for over half a dozen different sockets.

Programming is very similar to the N8 2511 board and JUHA interfaces, so driver code should be available in the near future.

Hardware documentation

Schematic: ecb_dual_sd_101-schematic.pdf

PCB layout: sdcard-printable-layout.gif

File List

FilenameFilesizeLast modified
dual_sdcard_100.doc23.5 KiB2015/11/01 19:03
dual_sdcard_100.pdf23.0 KiB2015/11/01 19:03
dual_sdcard_configuration.doc19.0 KiB2015/11/01 19:03
dual_sdcard_configuration.pdf23.4 KiB2015/11/01 19:03
dual_sdcard_footprint.doc1013.0 KiB2015/11/01 19:03
dual_sdcard_footprint.pdf1.1 MiB2015/11/01 19:03
ecb_dual_sd_-_bill_of_materials.txt2.3 KiB2015/11/01 19:04
ecb_dual_sd_100-schematic-obsolete.pdf239.2 KiB2015/11/01 19:03
ecb_dual_sd_100-schematic.pdf239.2 KiB2015/11/01 19:03
ecb_dual_sd_101-schematic.pdf242.3 KiB2015/11/01 19:04
sbc816rom.zip1.1 MiB2017/12/25 17:40
sdcard-assembled.jpg121.6 KiB2015/11/01 19:04
sdcard-back.jpg291.6 KiB2015/11/01 19:04
sdcard-components.jpg234.6 KiB2015/11/01 19:04
sdcard-fci-jumpers.jpg77.0 KiB2015/11/01 19:04
sdcard-front.jpg290.2 KiB2015/11/01 19:04
sdcard-printable-layout.gif339.7 KiB2015/11/01 19:04