TX-2 / TX-2-simulator

Simulator for the pioneering TX-2 computer
https://tx-2.github.io/
MIT License
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Opcode RSX: ensure R(Xj) can be cleared by sign extension #55

Closed jamesyoungman closed 2 years ago

jamesyoungman commented 2 years ago

On page 3-15 of the Users Handbook, example 6 shows that the sign bit of Q4 of T is copied into all the bits of Xj.

This is an interesting example because most examples only show sign extension happening into the further-left bits of the E register. This example shows sign extension happening in an X register. Example 4 on the previous page also shows sign extension.