Microprograms can be edited in the Microprogram Editor Window. Conceptually, you are directly manipulating bits within the control store of the computer. Consequently, only the binary code can be edited. No other editing changes are possible (or appropriate). As you edit a microinstruction, the disassembled mal (micro assembly language) version will be updated to reflect the changes. Copy, cut, and paste operations are supported but each works only with an entire 36-bit microinstruction. You can not copy, cut, or paste just a portion of a microinstruction.
The microprogram editor responds to the keystrokes listed below. In most cases the results are what you would expect though there are some differences. Since you cannot delete a bit in the control store, the "Backspace" key is just an alternate for the left arrow key. The "Delete" key doesn't delete a bit; it resets the bit to zero and moves right one bit (as though you had tapped the '0' key). The "Enter" key behaves like the down arrow key.
Keystroke |
Action |
Left Arrow | Move one bit to the left (with wrap-around) |
Backspace | Same as left arrow |
Home | Move to the left-most bit |
Right Arrow | Move one bit to the right (with wrap-around) |
End | Move to the right-most bit |
Up Arrow | Move up one line |
Page Up | Move up one page |
Ctrl-Home | Move up to the first microinstruction |
Down Arrow | Move down one line |
Enter | Same as down arrow |
Page Down | Move down one page |
Ctrl-End | Move down to the last microinstruction |
Ctrl-C | Copy the microinstruction on the current line to the clipboard |
Ctrl-V | Paste the microinstruction on the clipboard to the current line (replacing the existing microinstruction) |
Ctrl-X | Cut the microinstruction on the current line (copy it to the clipboard and replace it with all zeroes) |
0 | Set the current bit to 0 and move right one bit (with wrap-around) |
Delete | The same as 0 |
1 | Set the current bit to 1 and move right one bit (with wrap-around) |