Showing posts from March, 2016

User Interface Construction: Instruction, Clock and Sequencer

Well, the good news is I've just passed a major milestone in constructing this relay computer ... it can now perform a single instruction in full firing the various control lines as needed. The bad news ... I'm rather behind in blogging about it so this will be the first of a couple of 'catch up' posts which will culminate in a video showing off the computer as it currently stands.

The last outstanding item from the MOV-8, ALU and SETAB series of construction is updating the computer's user interface so that the contents of the instruction register and the actions of the control and sequencer cards can be observed. The first job was to apply the legends to the new buttons and indicators that I'd be adding to the two display cards. Here's a close up picture: The buttons at the top are (from left to right) clock, instruction to bus (I2B), instruction load and condition load. Below that are the instruction class indicators: MOV8 and SETAB. The ALU instruction…