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Table of Contents
SBC V1
The SBC-V1 is the creation of Andrew Lynch. Formerly known as the N8VEM Z80 SBC after Andrews call sign, it launched a tsunami of developments based on the Euro Card Bus (ECB) standard. Much of the initial records on development from 2006 have been lost but some pictures remain and the evolution can be picked up from the April-2008 archive
Features
- Z80 CPU
- 1024Kb EPROM support
- 512Kb RAM support
- 32K paged memory mapping
- RS232 level serial Interface
- Parallel port interface
- Can operate independently as a single board computer.
- ECB standard form factor and bus interface.
- Reset button.
- Real time clock with battery backup connector
- Power on LED
- Standard molex power connector.
Pictures
Changes from V1
The V2 is upward compatible. The main difference is the added jumpers to allow 48k/16k memory mapping as an alternate to 32k/32k. All of the V1 software will run on the V2 with default jumpers.
The V2 board has major corrections to the external Bus Master logic to support DMA. The V1 board is not able to support DMA. Since there are no add-on boards which have a DMA controller, this circuit update has never been tested or used.
The serial interface is jumper configurable to support DTR/DSR protocol (V1 compatible), or RTS/CTS protocol (not on the V1).
There is an DS1210 on the V2 board to provide 512k SRAM battery backup. The V1 does not have this capability. The RTC SRAM is battery backed on both boards.
There is an option jumper on the Parallel Interface connector to strap pin 25 to either GND or +5v. On the V1 board this pin is tied to GND.
The V1 board has a Power On LED; the V2 board has a HALT(red)/RUN(green) bi-color LED. This is considered extremely cool.
