Undo the 3 screws at the back of the 1401plus that secure the lid, and remove the lid by lifting it at the rear and sliding it away from the front of the 1401plus.

There are two circuit boards mounted on hinged frames inside the 1401plus. The upper is the Analogue (1401-4) board, the lower is the Processor (2101-1) board. The Monitor ROM must be installed in the 2101-1 lower board.

To gain access to the 2101-1, push the top frame over to the right so that it can be lifted into the vertical position, where it will lock into place.

The 2101-1 board is now visible. The diagram shows the Monitor ROM, the large chip in black at the top.

CAUTION! This chip can be damaged by static electricity and must not be removed from the board or conductive foam until you have taken steps to earth yourself (by touching the computer chassis for example). DO NOT touch the pins of the chips at any time. Carefully remove the old chip from the socket with a chip extractor or lever them out with a small, flat bladed screwdriver.

Remove the new chip from the conductive foam and carefully insert them in the socket, correctly oriented - the notch at one end of the chip should match the notch on the socket. Check that all the pins have enter the sockets correctly.

Refitting of the boards and 1401plus lid is in the reverse sequence to their raising and removal. If we sent you the ROM, please return the old chip to CED in the protective foam.