Simulating a TI calculator with crazy 11-bit opcodes

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16 pointskens4 comments

Hi good job with the emulator, just one thing though when you are describing the op-code length and encoding in the 3rd paragraph of 'Architecture' you say: " The first two bits of an instruction are the "class", selecting the type of instruction (arithmetic, flag, or branch). The next 5 bits select the specific instruction opcode. The final five bits select the mask and constant."

But shouldn't the mask and constant bits equal 4 as is demonstrated in the diagram?

Thanks for finding that. I've fixed it.

This is really awesome. I think that it'd be really cool to use as a visual in a Computer Architecture course, for sure.

Thanks. I think the architecture is very interesting how it violates expectations by having 11 bit words and 44 bit registers. The way the keyboard scan and display scan is tied in with the register processing is also unusual. The masks that select which digits are used makes up for the small number of registers.

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