PETSCII control codes¶

BPP+ supports PETSCII control codes using curly-brace notation {code} for screen control, colors, and special characters. These codes are automatically converted during preprocessing.

Colors¶

Text colors¶

Code	Description	Example
`{wht}` or `{white}`	White	`print "{wht}white text"`
`{red}`	Red	`print "{red}red text"`
`{grn}` or `{green}`	Green	`print "{grn}green text"`
`{blu}` or `{blue}`	Blue	`print "{blu}blue text"`
`{blk}` or `{black}`	Black	`print "{blk}black text"`
`{orng}` or `{orange}`	Orange	`print "{orng}orange text"`
`{brn}` or `{brown}`	Brown	`print "{brn}brown text"`
`{lred}` or `{pink}`	Light Red / Pink	`print "{lred}pink text"`
`{gry1}` or `{dark gray}`	Dark Gray	`print "{gry1}dark gray"`
`{gry2}` or `{gray}`	Gray	`print "{gry2}gray text"`
`{lgrn}` or `{light green}`	Light Green	`print "{lgrn}light green"`
`{lblu}` or `{light blue}`	Light Blue	`print "{lblu}light blue"`
`{gry3}` or `{light gray}`	Light Gray	`print "{gry3}light gray"`
`{pur}` or `{purple}`	Purple	`print "{pur}purple text"`
`{yel}` or `{yellow}`	Yellow	`print "{yel}yellow text"`
`{cyn}` or `{cyan}`	Cyan	`print "{cyn}cyan text"`

Screen control¶

Cursor movement¶

Code	Description	Example
`{home}`	Move cursor to home position (top-left)	`print "{home}"`
`{clr}` or `{clear}`	Clear screen	`print "{clr}"`
`{up}`	Cursor up	`print "{up}"`
`{down}`	Cursor down	`print "{down}"`
`{left}`	Cursor left	`print "{left}"`
`{rght}` or `{right}`	Cursor right	`print "{rght}"`

Repetition syntax¶

Certain PETSCII control codes can be repeated using a numeric prefix or suffix:

print "{3 right}"       rem Same as {right}{right}{right}
print "{right*3}"       rem Same as above (alternative syntax)
print "{5 down}"        rem Same as {down}{down}{down}{down}{down}
print "{10 space}"      rem 10 spaces
print "{space*10}"      rem Same as above

Patterns: {number code} or {code*number}

Both formats produce identical output. Use whichever format you find more readable.

Important limitation¶

The repetition syntax ONLY works with predefined PETSCII control codes listed in this document. It does NOT work with regular keyboard characters like letters, numbers, or basic punctuation.

rem WORKS: Repeating control codes (both syntaxes)
print "{40 space}"      rem 40 spaces
print "{space*40}"      rem Same as above
print "{20 down}"       rem Move down 20 lines
print "{down*20}"       rem Same as above
print "{home}{25 down}" rem Position cursor at line 25

rem WORKS: PETSCII graphic characters (CBM + key combinations)
print "{40 cbm-t}"      rem 40 horizontal line characters
print "{cbm-t*40}"      rem Same as above
print "{20 cbm-q}"      rem 20 vertical line characters
print "{10 shift-*}"    rem 10 filled circle characters

rem DOES NOT WORK: Regular keyboard characters
print "{20 *}"          rem ERROR: Plain * is not a control code
print "{10 a}"          rem ERROR: Plain letters don't work
print "{40 -}"          rem ERROR: Plain hyphen doesn't work

Display control¶

Code	Description	Example
`{rvson}` or `{reverse on}`	Reverse video on	`print "{rvson}reversed"`
`{rvof}` or `{rvsoff}` or `{reverse off}`	Reverse video off	`print "{rvof}normal"`
`{inst}` or `{insert}`	Insert character	`print "{inst}"`
`{del}` or `{delete}`	Delete character	`print "{del}"`

Character set control¶

Code	Description	Example
`{swlc}` or `{lower case}`	Switch to lowercase character set	`print "{swlc}"`
`{swuc}` or `{upper case}`	Switch to uppercase character set	`print "{swuc}"`
`{dish}`	Disable SHIFT+Commodore	`print "{dish}"`
`{ensh}`	Enable SHIFT+Commodore	`print "{ensh}"`

Function keys¶

Code	Description	Example
`{f1}`	Function key F1	`print "{f1}"`
`{f2}`	Function key F2	`print "{f2}"`
`{f3}`	Function key F3	`print "{f3}"`
`{f4}`	Function key F4	`print "{f4}"`
`{f5}`	Function key F5	`print "{f5}"`
`{f6}`	Function key F6	`print "{f6}"`
`{f7}`	Function key F7	`print "{f7}"`
`{f8}`	Function key F8	`print "{f8}"`

Special characters¶

Code	Description	Example
`{space}`	Space character	`print "word{space}word"`
`{return}`	Return character	`print "line1{return}line2"`
`{sret}` or `{shift return}`	Shift+Return	`print "{sret}"`
`{stop}`	STOP key	`print "{stop}"`
`{esc}`	ESC key	`print "{esc}"`

Control characters (Low-level)¶

CTRL sequences¶

BPP+ supports direct CTRL key combinations:

Code	Description
`{ctrl-a}` through `{ctrl-z}`	Control + letter combinations
`{ctrl-3}`, `{ctrl-6}`, `{ctrl-7}`	Control + number combinations

CBM (Commodore) key sequences¶

Code Pattern	Description
`{cbm-letter}`	Commodore key + letter (e.g., `{cbm-a}`, `{cbm-z}`)
`{cbm-symbol}`	Commodore key + symbol (e.g., `{cbm-*}`, `{cbm-+}`)

SHIFT sequences¶

Code Pattern	Description
`{shift-letter}`	Shift + letter (e.g., `{shift-a}`, `{shift-z}`)
`{shift-symbol}`	Shift + symbol (e.g., `{shift-*}`, `{shift-@}`)
`{shift-space}`	Shifted space

Raw hex values¶

For direct character codes, use hex notation:

print "{$00}"    rem Character code 0
print "{$1f}"    rem Character code 31
print "{$ff}"    rem Character code 255

Usage examples¶

Clear screen and set colors¶

init:
    print "{clr}{blu}"              rem Clear screen, blue text
    print "{home}WELCOME{return}"   rem Title at top
    return

menu:
    print "{clr}"
    print "{yel}MAIN MENU{wht}"
    print
    print "{grn}1.{wht} START GAME"
    print "{grn}2.{wht} OPTIONS"
    print "{grn}3.{wht} QUIT"
    return

Reverse video highlight¶

highlight:
    print "{rvson}>>> SELECTED <<<{rvof}"
    return

Cursor positioning with repetition¶

status:
    print "{home}{3 down}"           rem Move to line 4
    print "{5 right}"                rem Move 5 columns right
    print "SCORE: ";$sc
    return

Character set switching¶

init_screen:
    print "{clr}{swlc}"              rem Clear and switch to lowercase
    print "Mixed CASE text"
    print "{swuc}"                   rem Back to uppercase
    return

Drawing patterns with PETSCII graphics¶

border:
    print "{home}{40 cbm-t}"             rem Top border with repetition
    print "{home}{23 down}{40 cbm-t}"    rem Bottom border
    return

box:
    print "{home}{cbm-@}";               rem Top-left corner
    for i=1 to 38: print "{cbm-t}";: next i
    print "{cbm-i}"                      rem Top-right corner
    return

Common line drawing characters: {cbm-t} (horizontal), {cbm-q} (vertical), {cbm-@}, {cbm-i}, {cbm-k}, {cbm-j} (corners)

Case insensitivity¶

Control codes are case-insensitive. These are equivalent:

print "{clr}"     rem lowercase
print "{CLR}"     rem uppercase
print "{Clr}"     rem mixed case

Alternative names¶

Many control codes have multiple aliases:

{clr} = {clear}
{rvson} = {reverse on}
{wht} = {white}
{rght} = {right}
{del} = {delete}

Use whichever form is most readable in your code.

Technical notes¶

Internal processing¶

Control codes are processed during the preprocessing stage:

Codes are temporarily escaped to ~code~ format during parsing
Label resolution and line generation occurs
Codes are unescaped back to {code} format in output
Petcat converts them to actual PETSCII bytes during tokenization

Conflicting with BASIC code¶

Control codes in string literals are safe:

rem CORRECT: In strings
print "{clr}HELLO"

rem WRONG: Not in strings - will cause parse errors
a={clr}

Control codes should only appear in string literals, not in BASIC expressions.