Put current color, at memory address $0286, into color RAM, pointed at by memory addresses $00F3-$00F4.
Input: Y = Column number.
Output: –
Used registers: A.

Fetch number of screen rows and columns.
Input: –
Output: X = Number of columns (40); Y = Number of rows (25).
Used registers: X, Y.

Save or restore cursor position.
Input: Carry: 0 = Restore from input, 1 = Save to output; X = Cursor row (if Carry = 0); Y = Cursor column (if Carry = 0).
Output: X = Cursor row (if Carry = 1); Y = Cursor column (if Carry = 1).
Used registers: X, Y.

Initialize VIC; restore default input/output to keyboard/screen; clear screen.
Input: –
Output: –
Used registers: A, X, Y.

Clear screen.
Input: –
Output: –
Used registers: A, X, Y.

Move cursor home, to upper left corner of screen.
Input: –
Output: –
Used registers: A, X, Y.

Set pointer at memory addresses $00D1-$00D2 to current line in screen memory and pointer at memory addresses $00F3-$00F4 to current line in Color RAM, according to current cursor row, at memory address $00D6, and column, at memory address $00D3.
Input: –
Output: –
Used registers: A, X, Y.

Initialize VIC; restore default input/output to keyboard/screen; move cursor home.
Input: –
Output: –
Used registers: A, X, Y.

Initialize VIC; restore default input/output to keyboard/screen.
Input: –
Output: –
Used registers: A, X.

Initialize VIC.
Input: –
Output: –
Used registers: A, X.

Read byte from screen; if input line is empty, the cursor appears and a line of data is input.
Input: –
Output: A = Byte read.
Used registers: A.

Check PETSCII code; if $22, quotation mark, then toggle quotation mode switch, at memory address $00D4.
Input: –
Output: –
Used registers: –

Recompute the high bytes of pointers to lines in screen memory, at memory addresses $00D9-$00F1.
Input: –
Output: –
Used registers: A, X, Y.

Write byte to screen.
Input: A = Byte to write.
Output: –
Used registers: –

Check PETSCII code; if belongs to a color, set current color, at memory address $0286.
Input: –
Output: –
Used registers: A, X.

Scroll complete screen upwards.
Input: –
Output: –
Used registers: A, X, Y.

Insert line before current line and scroll lower part of screen downwards.
Input: –
Output: –
Used registers: A, X, Y.

Set pointer at memory addresses $00D1-$00D2 to current line in screen memory, fetching high byte from table at memory addresses $00D9-$00F1.
Input: X = Row number.
Output: –
Used registers: A.

Clear screen line.
Input: X = Row number.
Output: –
Used registers: A, Y.

Write character and color onto screen; set cursor phase delay to 2.
Input: A = Character to write; X = Color to write.
Output: –
Used registers: A, Y.

Set pointer at memory addresses $00F3-$00F4 to current line in Color RAM, according to pointer at memory addresses $00D1-$00D2 to current line in screen memory.
Input: –
Output: –
Used registers: –

SCREEN. Fetch number of screen rows and columns.
Input: –
Output: X = Number of columns (40); Y = Number of rows (25).
Used registers: X, Y.
Real address: $E505.

PLOT. Save or restore cursor position.
Input: Carry: 0 = Restore from input, 1 = Save to output; X = Cursor column (if Carry = 0); Y = Cursor row (if Carry = 0).
Output: X = Cursor column (if Carry = 1); Y = Cursor row (if Carry = 1).
Used registers: X, Y.
Real address: $E50A.