Revision as of 22:14, 9 March 2016

This is a partial, work-in-progress examination of the bytecode created when Lingo code is compiled in Macromedia Director 4.0. It describes instructions for a stack-based virtual machine. This virtual machine is sometimes known as the IML, or Idealized Machine Layer.

Each instruction is one, two or three bytes.

If the first byte is in the range 0x00-0x3F, then the full instruction is one byte.
If the first byte is in the range 0x40-0x7F, then the full instruction is two bytes.
If the first byte is in the range 0x80-0xFF, then the full instruction is three bytes.

Constant blobs like string literals are stored after the bytecode, and referred to by records that are six bytes long regardless of the actual length of the data. This means the first constant will be referred to as 0x00, the second constant as 0x06, the third as 0x0C, and so on. Integer literals over 32767 and floating-point number literals are also stored as constants.

There is also a namelist for referring to external identifiers, stored separately from the bytecode. This is a simple array of strings.

One-Byte Instructions

File Format
Name	Lingo bytecode
Ontology	Electronic File Formats Development Lingo bytecode ; ; ;

01 exit Leave the current function immediately and return to its caller. Automatically added as the final step of a function.

02

03

0

FALSE

+1

Push zero onto the stack.

04 (a * b) -2 +1 Pop two values from the stack, multiply them together and push the result.

05 (a + b) -2 +1 Pop two values from the stack, add them together and push the result.

06 (a - b) -2 +1 Pop two values from the stack, subtract the second from the first and push the result.

07 (a / b) -2 +1 Pop two values from the stack, divide the first by the second and push the result.

08 (a mod b) -2 +1 Pop two values from the stack, perform a modulo operation and push the result.

09 (-a) -1 +1 Pop one value from the stack, negate it and push the result.

0A (a & b) -2 +1 Pop two values from the stack, concatenate them and push the resulting string.

0B (a && b) -2 +1 Pop two values from the stack, concatenate them with one space character added in between, and push the resulting string.

0C (a < b) -2 +1 Pop two values from the stack, push 1 if the first is less than the second and 0 if not.

0D (a <= b) -2 +1 Pop two values from the stack, push 1 if the first is less than or equal to the second and 0 if not.

0E (a <> b) -2 +1 Pop two values from the stack, push 0 if the two values are the same and 1 if they are not.

0F (a = b) -2 +1 Pop two values from the stack, push 1 if the two values are the same and 0 if they are not.

10 (a > b) -2 +1 Pop two values from the stack, push 1 if the first is greater than the second and 0 if not.

11 (a >= b) -2 +1 Pop two values from the stack, push 1 if the first is greater than or equal to the sceond and 0 if not.

12 (a and b) -2 +1 Pop two values from the stack, push 1 if both are logically true and 0 if not.

13 (a or b) -2 +1 Pop two values from the stack, push 1 if either are logically true and 0 if not.

14 (not a) -1 +1 Pop one value from the stack, push 0 if it is logically true and 1 if not.

15

(a contains b)

-2

+1

Pop two values from the stack, push 1 if the first is a string that contains the second and 0 if not.

The text comparison is case-insensitive and ignores diacritic marks, e.g. "a" and "Å" are treated the same.

16

(a starts b)

-2

+1

Pop two values from the stack, push 1 if the first is a string that begins with second string and 0 if not.

The text comparison is case-insensitive and ignores diacritic marks, e.g. "a" and "Å" are treated the same.

17

(char a of c)

(char a to b of c)

(item 1 to 3 of someItems)

-9

+1

String slice/split operation. It takes nine arguments from the stack:

-9	First char position
-8	Last char position
-7	First word position
-6	Last word position
-5	First item position (items separated by `the itemDelimiter`, which is a comma by default)
-4	Last item position
-3	First line position
-2	Last line position
-1	The string to slice

The positions used here are one-based, so zero is invalid as a position and is instead used to indicate unused parameters. Only one "first X position" can be set, the rest must be zero. The corresponding "last X position" may either be set too, or it can be zero, in which case the first position will also be used as the last.

18

hilite word 1 of field 10

-9

Highlight (select) some text. The nine arguments taken from the stack are:

-9	First char position
-8	Last char position
-7	First word position
-6	Last word position
-5	First item position
-4	Last item position
-3	First line position
-2	Last line position
-1	Field number (cast ID)

The positions used here are one-based, so zero is invalid as a position and is instead used to indicate unused parameters. Only one "first X position" can be set, the rest must be zero. The corresponding "last X position" may either be set too, or it can be zero, in which case the first position will also be used as the last.

19 (sprite 1 intersects 2) -2 +1 Pop two sprite IDs and push 1 if the bounding rectangles of the two sprites touch at all, or 0 if they do not.

1A (sprite 1 within 2) -2 +1 Pop two sprite IDs and push 1 if the bounding rectangle of the first is entirely inside the bounding rectangle of the second, or 0 if not.

1B (field 1) -1 +1 Pop a cast ID (name or number), push the value of that cast member's text property.

1C tell someObject to go to frame 1 -1 Pop an object from the stack and begin running subsequent bytecodes in the context of that object, until code 1D is encountered.

1D tell someObject to go to frame 1 Marker for the end of a sequence of bytecodes started by 1C. Similar to 01 except for nested bytecode chunks instead of the main one.

1E -1 +1 Some kind of list transformation or check, seen used just before setting the actorList to []. More research is needed to know exactly what is happening there.

1F [#key: value] -1 +1 Pops a list that must be in the form [#symbol1, val1, #symbol2, val2 ...] to transform into [#symbol1: val1, #symbol2: val2 ...]

Two-Byte Instructions

41 XX 1 .. 127 +1 Push integer of value XX, which must be between 1 and 127, inclusive. To push zero, use 03. To push larger integers, use 81 XX YY.

42 XX a, b, c -XX +1 Pop the specified number of values off the top of the stack, create an unparenthesized argument list containing them (i.e. for a call statement like myFunction 1, 2, 3), and push that to the stack.

43 XX [a, b, c] -XX +1 Pop the specified number of values off the top of the stack, create a list for them (which can also be used for a parenthesized call expression like set result = myFunction(1, 2, 3)), and push that to the stack.

44 XX

"literal"

0.5

32768

+1

Push a constant from local constant records onto the stack. These records seem to be six bytes long (regardless of the actual size of the constant value), so pushing the first one is 44 00, the second is 44 06, the third is 44 0C, etc.

45 XX #symbol +1 Push a symbol with a name from namelist[XX]. Note that the name will be stored as "name", not "#name".

46 XX

47 XX

48 XX

49 XX

(someGlobal)

where previously declared:

global someGlobal

+1

Push the value of a global variable with a name from namelist[XX].

4C XX (someLocal) +1 Push the value of a local variable. The local variable records seem to be 6 bytes long, so the first is pushed with 4C 00, the second with 4C 06, etc.

4D XX

4E XX

4F XX set someGlobal = 0 -1 Pop one value and use it to set the global variable with name from namelist[XX].

50 XX

51 XX

52 XX set someLocal = 0 -1 Pop one value and use it to set a local variable. See code 4C 00 for a note about local variable records.

53 XX

54 XX end repeat Unconditional backwards jump by XX bytes, relative to the first byte of this instruction.

55 XX

56 XX localFunction(1,2,3) -1 +1 or +0 Call a function defined in this script with the name at namelist[XX]. The top value on the stack must be an argument list. If the argument list was created with code 43 XX, one return value will be pushed to the stack. If the argument list was created with code 42 XX, no return value will be pushed.

57 XX

someFunction 1,2,3

(someFunction(1,2,3))

-1

+1 OR +0

Call the external function with name from namelist[XX]. The top value on the stack must be an argument list. If the argument list was created with code 43 XX, one return value will be pushed to the stack. If the argument list was created with code 42 XX, no return value will be pushed.

58 XX

59 16 put "extra" into textVar -1 (Not sure how the target value is specified, needs more research)

59 25 put "extra" after textVar -1 (See above)

59 35 put "extra" before textVar -1 (See above)

5A XX

5B 05 delete word 3 of textVar -1 (See above)

5C 00

(the abbr time)

(the short date)

(the last word in someText)

-1 OR -2

+1

If the top value is a time-formatting ID, pop it from the stack, and push the current time formatted using it:

06	`the short time`
07	`the abbreviated time`, `the abbrev time`, `the abbr time`
08	`the long time`

If the top value is a date-formatting ID, pop it from the stack, and push the current date formatted using it:

09	`the short date`
0A	`the abbreviated date`, `the abbrev date`, `the abbr date`
0B	`the long date`

If the top value is a slice type ID, pop both it and the previous value from the stack. The previous value will be a string, slice the last "bit" of it according to the slice type, and push the sliced value:

0C	`the last char`
0D	`the last word`
0E	`the last item`
0F	`the last line`

5C 01

(the number of chars in someText)

-2

+1

Pop [text, stat ID] and push the stat value for the given text, using these stat IDs:

01	chars
02	words
03	items (separated by `the itemDelimiter`, which is a comma by default)
04	lines

5C 02

(the name of menu 1)

-2

+1

Pop [menu ID, property ID] and push the value of the specified menu property, using these property IDs:

01	`name`
02	`number of menuItems`

5C 03

(the name of menuItem 3 of menu 1)

-3

+1

Pop [item ID, menu ID, property ID] and push the value of the specified menu item property, using these property IDs:

01	`name`
02	`checkMark`
03	`enabled`
04	`script`

5C 04

(the volume of sound 1)

-2

+1

Pop [sound ID, property ID] and push the value of the specified sound property, using these property IDs:

01	`volume` (0 to 255)

5C 06

(the cursor of sprite 3)

-2

+1

Pop [sprite ID, property ID] and push the value of the specified sprite property, using these property IDs:

01	`type`
02	`backColor`
03	`bottom`
04	`castNum`
05	`constraint`
06	`cursor`
07	`foreColor`
08	`height`
0A	`ink`
0B	`left`
0C	`lineSize`
0D	`locH`
0E	`locV`
0F	`movieRate`
10	`movieTime`
12	`puppet`
13	`right`
14	`startTime`
15	`stopTime`
16	`stretch`
17	`top`
18	`trails`
19	`visible`
1A	`volume` (-256 to 256, <= 0 is silent)
1B	`width`
1D	`scriptNum`
1E	`moveableSprite`
20	`scoreColor`

The values for type are:

0	inactive
1	bitmap
2	rectangle
3	rounded rectangle
4	oval
5	line top-left to bottom-right
6	line bottom-left to top-right
7	text
8	button
9	checkbox
10	radio button
16	undetermined (try the castType of the associated cast member)

5C 07

(the exitLock)

-1

+1

Pop a setting ID from the stack and push its value, using these setting IDs:

01	`the beepOn`
02	`the buttonStyle`
03	`the centerStage`
04	`the checkBoxAccess`
05	`the checkBoxType`
06	`the colorDepth`
08	`the exitLock`
09	`the fixStageSize`
13	`the timeoutLapsed`
17	`the selEnd`
18	`the selStart`
19	`the soundEnabled`
1A	`the soundLevel`
1B	`the stageColor`
1D	`the stillDown`
1E	`the timeoutKeyDown`
1F	`the timeoutLength`
20	`the timeoutMouse`
21	`the timeoutPlay`
22	`the timer`

5C 08

(the number of castMembers)

-1

+1

Pop a stat ID from the stack and push the stat, using these stat IDs:

02	`number of castMembers`
03	`number of menus`

5C 09

(the picture of cast "bob")

(the name of cast 3)

-2

+1

Pop [cast ID, property ID] from the stack and push the value of the cast property, using these property IDs:

01	`name`
02	`text`
08	`picture`
0A	`number`
0B	`size`
11	`foreColor`
12	`backColor`

5C 0C

(the textSize of field 1)

-2

+1

Pop [field ID, property ID] and push the value of the property for the given field according to these property IDs:

03	`textStyle`
04	`textFont`
05	`textHeight`
06	`textAlign`
07	`textSize`

5C 0D

(the sound of cast 5)

-2

+1

Pop [cast ID, property ID] and push the value of property for the given cast according to these property IDs:

10	`sound`

5D 00

when keyDown then beep

-2

Pop [statement, eventID] and set the statement (Lingo source code in a text string) to run on the given event:

01	`mouseDown`
02	`mouseUp`
03	`keyDown`
04	`keyUp`
05	`timeOut`

5D 03 set the enabled of menuItem 3 of menu 5 to FALSE -4 Pop [menuItem ID, menu ID, new value, property ID] and set the menu item property. See the table for code 5C 03 for menu item property IDs.

5D 04 set the volume of sound 3 to 255 -3 Pop [sound ID, new value, property ID] and set the menu item property. See the table for code 5C 04 for sound property IDs.

5D 06 set the constraint of sprite 3 to 0 -3 Pop [sprite ID, new value, property ID] and set the sprite property. See the table for code 5C 06 for sprite property IDs.

5D 07 set the exitLock to TRUE -2 Pop [new value, setting ID] and change the relevant setting. See the table for code 5C 07 for setting IDs.

5D 09 set the backColor of cast "bob" to 0 -3 Pop [cast ID, new value, property ID] and set the cast property. See the table for code 5C 09 for cast property IDs.

5D 0C set the textAlign of field 3 to "right" -3 Pop [field ID, new value, property ID] and set the field property. See the table for code 5C 0C for cast property IDs.

5D 0D set the sound of cast 3 to TRUE -3 Pop [cast ID, new value, property ID] and set the cast property. See the table for code 5C 0D for cast property IDs.

5E XX

5F XX (the someProperty) +1 Push the value of the contextual property with the name at namelist[XX].

60 XX set the someProperty to 0 -1 Pop a value and use it to set the contextual property with the name at namelist[XX].

61 XX (the someProperty of someVariable) -1 +1 Pop a property-owning object from the stack, and push the value of this object's property with the name at namelist[XX].

62 XX set the someProperty of someVariable to 1 -2 Pop [property-owning object, new value] from the stack and set the property of the object with the name at namelist[XX].

63 XX tell someObject to go to frame 1 -1 Remote call: Similar to 57 XX except runs in the context of a tell ... to block.

64 XX

+1

Push a copy of a value already on the stack, relative to the top where 00 is the top slot, 01 is one slot beneath the top, etc.

This is used by the compiler when generating bytecode for the repeat with i in list block, to keep state in the loop without allocating new local variables.

65 XX

-XX

Pop and discard XX values from the top of the stack.

This is used in the bytecode generated for a repeat with i in list block, to clean up at the end.

66 04

(the machineType)

-1

+1

Pop an empty list off the stack and push an ID representing the type of computer that we are running on:

1	Macintosh 512Ke
2	Macintosh Plus
3	Macintosh SE
4	Macintosh II
5	Macintosh IIx
6	Macintosh IIcx
7	Macintosh SE/30
8	Macintosh Portable
9	Macintosh IIci
11	Macintosh IIfx
15	Macintosh Classic
16	Macintosh IIsi
17	Macintosh LC
18	Macintosh Quadra 900
19	PowerBook 170
20	Macintosh Quadra 700
21	Classic II
22	PowerBook 100
23	PowerBook 140
24	Macintosh Quadra 950
25	Macintosh LCIII
27	PowerBook Duo 210
28	Macintosh Centris 650
30	PowerBook Duo 230
31	PowerBook 180
32	PowerBook 160
33	Macintosh Quadra 800
35	Macintosh LC II
42	Macintosh IIvi
46	Macintosh II vx
47	Macintosh Color Classic
48	PowerBook 165c
50	Macintosh Centris 610
52	PowerBook 145
76	Macintosh Quadra 840av
256	IBM PC-type machine

66 05 (the pathName) -1 +1 Pop an empty list and push a string containing the full OS path of the folder which contains the current movie file.

66 2E (the date) -1 +1 Pop an empty list off the stack and push the current date with default formatting (same as "the short date").

66 3C (the time) -1 +1 Pop an empty list off the stack and push the current time with default formatting (same as "the short time").

Three Byte Instructions

81 XX YY	`128` .. `32767`		+1	Push the integer ((XX * 0x100) + YY). Larger integers and floats are pushed using constants.
82 XX YY	`someFunc 1, 2, 3,` (...) `254, 255, 256, 257`	-((XX * 0x100) + YY)	+1	Pop ((XX * 0x100) + YY) values from the stack and push a no-return-value argument list object containing these values. Similar to code 42 XX, only necessary when there are more than 255 arguments in the list.
83 XX YY	`[1, 2, 3,` (...) `254, 255, 256, 257]`	-((XX * 0x100) + YY)	+1	Pop ((XX * 0x100) + YY) values from the stack and push a list object containing these values. Similar to code 43 XX, only necessary when there are more than 255 items in the list.
93 XX YY	`else` `exit repeat` `next repeat`			Unconditional jump: Advance by ((XX * 0x100) + YY) bytes, relative to the first byte of this instruction (i.e. it may be 3 more than you are expecting) (`next repeat` jumps forward to `end repeat` instead of jumping back itself)
95 XX YY	`if somethingIsTrue then` `repeat while somethingIsTrue`	-1		Conditional jump: Pop a value, and if it is logically FALSE, advance by ((XX * 0x100) + YY) bytes, relative to the first byte of this instruction

Syntactic Sugar

Some functions get special syntax when written out in source code, but under the hood, the compiler just transforms it into more regular syntax. Here is a mapping that shows the equivalent in plain, generalized Lingo that gets used for the bytecode.

Specialized Syntax	Generalized Syntax
`play frame 10 of movie "theMovie"`	`play 10, "theMovie"`
`play frame 10`	`play 10`
`play movie "theMovie"`	`play 1, "theMovie"`
`play done`	`play`
repeat with i = 15 to 20 ... end repeat	set i = 15 repeat while i <= 20 ... set i = i + 1 end repeat
repeat with i = 15 down to 10 ... end repeat	set i = 15 repeat while i >= 10 ... set i = i - 1 end repeat
`sound fadeIn 5`	`sound #fadeIn, 5`
`sound fadeIn 5, 10`	`sound #fadeIn, 5, 10`
`sound fadeOut 5`	`sound #fadeOut, 5`
`sound fadeOut 5, 10`	`sound #fadeOut, 5, 10`
`sound playFile 1, "Thunder"`	`sound #playFile, 1, "Thunder"`
`sound close 1`	`sound #close, 1`
`go to frame 10` `go frame 10` `go to 10`	`go 10`
`go to movie "theMovie"` `go movie "theMovie"`	`go 1, "theMovie"`
`go to frame 10 of movie "theMovie"` `go frame 10 of movie "theMovie"` `go to 10 of movie "theMovie"` `go 10 of movie "theMovie"`	`go 10, "theMovie"`
`go loop`	`go #loop`
`go next`	`go #next`
`go previous`	`go #previous`
`open "document" with "application"`	`open "document", "application"`

`Lscr` bytecode-container chunk layout

Header

...
$0040-$0041	uint16	Offset to the function records block
...
$0048-$0049	uint16	Number of function records
...

Function Record

Each function record is 42 bytes long.

$0000-$0001	uint16	Namelist index for the function's name, or 0xFFFF if there is no name(?)
$0002-$0003	uint16	Unknown
$0004-$0007	uint32	Length of the function bytecode in bytes
$0008-$000B	uint32	Offset to the function bytecode
$000C-$000D	uint16	Number of arguments
$000E-$0011	uint32	Unknown
$0012-$0013	uint16	Number of local variables
$0014-$0017	uint32	Unknown
$0018-$0019	uint16	Count (C)
$001A-$001D	uint32	Unknown
$001E-$0021	uint32	Unknown
$0022-$0023	uint16	Unknown
$0024-$0025	uint16	Count (D)
$0026-$0029	uint32	Unknown

Bytecode Trailer

After the bytecode section for a function (determined using the offset and length fields from the function record), and then after an additional padding byte if there are an odd number of bytes in the bytecode, are the following values:

For each argument: uint16 namelist index for the argument's name
For each local variable: uint16 namelist index for the variable's name
Count (C) * uint16
Count (D) * uint8
A padding byte if Count (D) is an odd number

@@ Line 686: / Line 686: @@
 Pop a setting ID from the stack and push its value, using these setting IDs:
 {| class="wikitable"
+|-
+! 01
+| <code>the beepOn</code>
+|-
+! 02
+| <code>the buttonStyle</code>
+|-
+! 03
+| <code>the centerStage</code>
+|-
+! 04
+| <code>the checkBoxAccess</code>
+|-
+! 05
+| <code>the checkBoxType</code>
+|-
+! 06
+| <code>the colorDepth</code>
 |-
 ! 08
 | <code>the exitLock</code>
+|-
+! 09
+| <code>the fixStageSize</code>
+|-
+! 13
+| <code>the timeoutLapsed</code>
+|-
+! 17
+| <code>the selEnd</code>
+|-
+! 18
+| <code>the selStart</code>
+|-
+! 19
+| <code>the soundEnabled</code>
+|-
+! 1A
+| <code>the soundLevel</code>
+|-
+! 1B
+| <code>the stageColor</code>
+|-
+! 1D
+| <code>the stillDown</code>
+|-
+! 1E
+| <code>the timeoutKeyDown</code>
+|-
+! 1F
+| <code>the timeoutLength</code>
+|-
+! 20
+| <code>the timeoutMouse</code>
+|-
+! 21
+| <code>the timeoutPlay</code>
+|-
+! 22
+| <code>the timer</code>
 |}
 |-

Lingo bytecode

Revision as of 22:14, 9 March 2016

Contents

One-Byte Instructions

Two-Byte Instructions

Three Byte Instructions

Syntactic Sugar

`Lscr` bytecode-container chunk layout

Header

Function Record

Bytecode Trailer

Personal tools

Namespaces

Variants

Views

Actions

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Lingo bytecode

Revision as of 22:14, 9 March 2016

Contents

One-Byte Instructions

Two-Byte Instructions

Three Byte Instructions

Syntactic Sugar

Lscr bytecode-container chunk layout

Header

Function Record

Bytecode Trailer

Personal tools

Namespaces

Variants

Views

Actions

Search

Navigation

Toolbox

`Lscr` bytecode-container chunk layout