Day 18: User Input

Yesterday we got a simple routine working that set a selected bit on a word using a few registers. Lets see if we can select that bit using the command line.

  1. output a message prompting the user for the bit to set
  2. read the input
  3. convert the ascii character to a number – as simple as subtracting 30H or 48 from the register?
  4. use that number as the bit number (register c), and run set bit
  5. go to 1

WELL… IT DOESN’T WORK. I can output the message, type a single character, then it locks up. not sure where it’s getting gobbed up – I’ve got a single character printing in the setbit routine and it doesn’t even get that far.

OK, that’s all for tonight.

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