Edit Memory in Memory Pane

[RupertAvery]

The user can edit memory in the Memory Pane while the emulator is running.

I decided to allow editing memory while the emulator is running, because unlike the status registers, it's more likely that memory doesn't change as often or at all while the emulator is running. Of course, if the user wants to stop the emulator before an instruction and edit memory, they can freely do so.

It could be useful editing variables while a program is running.

It's also possible to "write" to display memory manually and see the effects in real time.

This is not or related to nor is it intended to supplant the functionality of the ET3400's memory view and edit, which is a ROM-provided feature.

Selecting a memory cell

Clicking on a memory cell in the pane will select the memory cell.

While selected

Pressing the cursor keys will change the currently selected memory cell.

Editing a memory cell

Pressing F2 will enable editing mode. Double-clicking a cell will select and enable editing mode for the cell. The currently selected nibble will be the upper nibble.

Read-only memory-mapped devices such as the Keypad and Monitor ROM cannot be edited.

While editing a cell

• Pressing 0-F will overwrite the current nibble and move to the next nibble.
• If the user is editing the upper nibble, the next nibble will be selected.
• If the user is editing the lower nibble, the new value will be written to the memory cell and the cell in the next address will be selected and made editable.
• Pressing ESC will cancel editing without updating the value at the selected memory cell.
• Pressing Enter will update the value in the selected memory cell and cancel editing
• Pressing Left or Right will move the currently selected nibble, moving to the next or previous memory cell as required.

IMPORTANT - Since we use ESC for interacting with the Memory Pane, ESC no longer triggers Reset in the debugger view, as the user may accidentally press ESC too many times and reset the program unintentionally.

[RupertAvery]

@ricknun this is now in the latest version

https://github.com/RupertAvery/et3400/releases/tag/v0.10

[ricknun]

I tried this in v0.10, without reading the above instructions. I clicked a memory and it got blue highlighted. Interesting. More must be possible. So knowing a right-click in the Disassembly panel gives more options, I tried right-clicking in the Memory panel. No choices. Not what I expected. Consider making a right-click start the edit operation.

Then I tried double-click. Not what I expected. In the Disassembly panel clicking twice highlights and then takes away the highlight. I expected the same in the Memory panel, not starting the edit operation.

Then I read about F2, and I probably won't use that, but others might expect it.

I like the auto-advance to the next address and ESC to quit. I often want to change 16-bit values and it is nice to just type the 4 digits without interruption.

I like having the feature and the details of how to operate it are secondary. So feel free to close this issue or make more changes.