Programmers Aid (VIC-20)
The Programmers Aid cartridge was a cartridge that helped you write programs a little quicker.
With the cartridge inserted, on first boot, you see nothing different. You will be presented with the CBM BASIC V2 screen.
Type SYS 28681 and press Return. This will load the cartridge program and display Programmers' Aid.
Now you have some really useful shortcuts.
Keys | Function |
F1 | LIST |
F3 | RUN |
F5 | GOTO |
F7 | INPUT |
Shift + F1 (F2) | MID$( |
Shift + F3 (F4) | LEFT$( |
Shift + F5 (F6) | RIGHT$( |
Shift + F7 (F8) | CHR$( |
Say we want F1 to be PRINT instead of LIST, we can do this easily by typing the following command:
And hitting enter. Now when we press F1 it would type PRINT.
The Programmers Aid also has many commands you can type into BASIC to perform tasks faster.
Command | Description |
AUTO [NUM] | Generate line numbers automatically, incrementing by [NUM] |
CHANGE "OLD", "NEW" | Replace all occurrences of a given string "OLD", with "NEW" |
DELETE [NUM] | Delete line [NUM] from a program |
DUMP | Display the values of all variables |
EDIT | Use the EDIT set of function keys |
FIND "TEXT" | Locate all occurrences of a given string "TEXT" |
HELP | Indicate the location of an error |
KEY | Display or assign a string to a function key |
KILL | Disable all additional commands |
MERGE | Load a program, combining it with the current one |
OFF | Disable STEP or TRACE mode |
PROG | Use the PROG set of function keys |
RENUMBER [NUM] | Renumbers all line numbers to go up by 10, starting at [NUM] |
STEP | Eanbles stepping, so when RUN happens, program will pause every line until Shiftis pressed to move one line at a time. |
TRACE | Display the line number as a program is executed at top right. |
For example, DELETE 20 will delete the line 20.
Typing AUTO 10 will start entering program lines and every time you press Return it automatically adds 10 to the next line, so it would start at 10, then the next line would be 20, 30 and so on. Pressing enter on a blank line will exit.
As well as BASIC commands, there are useful screen commands using the Control key.
Keys | Description |
Ctrl + A | Scroll up a program list |
Ctrl + E | Cancel quote and insert modes |
Ctrl + L | Erase characters after cursor on same line |
Ctrl + N | Erase all characters in program after cursor |
Ctrl + Q | Scroll down a program list |
Ctrl + U | Erase all characters on cursor line |
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