SC119, v1.0, User Guide

Using SC119, v1.0, Z180 Memory module is pretty straight forward.

The module is designed to work with a Z180 processor, such as SC111, with the Z180 processor providing the memory management functions. The module has two Flash memory sockets to supports two sets of firmware, with a simple jumper or switch selection.

SC111, Z180 CPU (front), plus SC119, Z180 Memory (back)

The module only has three jumper options.

Jumper 3, shown below in yellow, selects which of the two Flash chips is used. Fit the jumper shunt to select Flash 1 (U1) or remove the shunt to select Flash 2 (U2).

JP3, Flash #1 select

The angled header pin (P2) next to JP3 allows connection of an external switch to select which Flash chip is used. It is possible to connect an external control signal to this header to allow software selection of the current Flash chip. This, in theory, allows access to 1M byte of Flash memory.

Jumpers, JP1 and JP2, shown below in yellow, enable each Flash chip to be independently write protected. It is unlikely the Flash chip will be corrupted in normal operation, due to the software requirements to write to it. However, for peace of mind you can disable writing with jumper shunts.

JP1 and JP2, write enable or disable

Each Flash chip has its own write protection jumper. Fit the shunt in the position shown below in green to disable writing. Alternatively, fit the shunt in the position shown below in red to enable writing.

Write enable (green) or disable (red)

In normal use it would be sensible to disable writing to the Flash chips, so set both shunts to the green position.

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