Fifth - virtual machine, operating system, programming language
- This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
- Program author:
- Other software projects hosted at svjatoslav.eu
Current implementation does not support object oriented programming. While working on Fifth I got lots of cool new ideas that require reimplementation of everything.
Currently I try to implement those new ideas in the project called Sixth
System is built many years ago when I was still using DOS as a primary operating system and not updated since.
Fifth is programming lanquage & operating system, running on virtual CPU, with custom instruction set. It is much like Charles Chunk Moore's Forth, it also uses stack architecture, and many commands are similar. Basically I got familiar with concepts of Forth, and being inspired created my own system.
- Startup screen diplaying Fifth logo and full file list.
- Sample words defined. Most of the words are commands that can be executed interactively from command line or from file. When executed they can be selectively compiled or interpreted.
- Built in text editor.
Just unpack all files, witout altering original directory structure, somewhere in your hard disk. For example:
To run fifth you need minimally just 2 files. emulator itself ( EMULATOR.EXE or EMULATOR.COM ), and virtual disk file ( DISK.RAW ).
Read more about distribution directory layout
5 Fifth distribution directory tree description
After downloading and unpacking the ZIP file you shoud get directory tree similar to this:
[DOC] - Fifth documentation
[commands] - documentation on Fifth built-in commands
[modules] - documentation on additional commands, realized as loadable modules
[shots] - Fifth screenshots
[imageFile] - files contained within 'disk.raw', just an extracted form.
[source] - source files
[emulator] - emulator source
[util] - utilites
disk.raw - Virtual disk file, has filesystem inside.
emulator.com - main executable.
6 Software/Hardware/Human requirements
- MS-DOS 6.22, with HIMEM.SYS loaded.
- Mouse driver if you have a mouse.
- Does work only when CPU is in real mode.
- To recompile ASM sources I used FASM (Flat Assembler).
- I ran QBasic utilities on QB 4.5 .
- VESA support by BIOS, or external driver (UNIVBE).
- Minimum CPU 386.
- 64 KB free RAM below 640KB,
- 2 MB of free XMS.
- VESA compatible video card.
- Beginner level Forth knowledge is recommended.
- Lots of enthusiasm.
7 Numbers representation within Fifth
Because I can define everything, starting from CPU, why not try also alternative and unique number representation ?
Fifth uses its hexdecimal number representation as primary. Numbers shape is formed by dividing a square into four parts. And manipulating their color (black or white).
8 Disk file map, and it's data structures
Core and high-level boot code is stored outside of the filesystem to allow easy access to it, at early booting time, when filesystem is not yet initialized.
8.1 disk allocation
|0||~4 Kb||Fifth core|
|4 Kb||~32Kb||high-level boot code|
|101Kb||~16MB||filesystem data area|
8.2 FAT entry format:
|0 --||.. pointer to next block|
8.3 file entry format
|28||4||last modification time|
9 Core architecture
Fifth core is simply some amount of already compiled into machine code and linked together modules (entries in other words). In compilation process modules is compiled one by one and simply stored on top of already existing and growing core. Separately from core is kept dictionary, this is special list that contain names of compiled modules, variables etc. and they locations in core. Constants use dictionary space only. Random word can be removed from dictionary at any time. Currently dictionary can contain at most 1000 entries.
9.1 Dictionary entry format
|0||4||0 < previous entry|
|0 = last|
|-1 = empty|
|4||15||module name string|
Core headers as linked list of module names make up something like dictionary. When some entry address is needed compiler can quickly run through headers backwards and find needed entry.
9.2 Possible module types
|0||data||compile "num" instruction|
|with address to module|
|1||submodule||compile "call" instruction|
|with address to module|
|2||imm. submodule||immediately call to module|
9.3 Memory map (average)
|1500000||~32000||highlevel Fifth boot code|
|200000h||core startup messages area|
|5200000||end of dynamic memory space|
10 Virtual machine
Using CPU emulator slows it down but I shouldn't now think too mutch about, and waste my time on batteling with problems whitch results on complex design of PC hardware. Also it allows me to use existing DOS and resident drivers services in real mode. So I don't need to deal with hardware too mutch. It also allows me to use all free XMS for flat code & data storage.
Current emulator emulates 1 CPU. It has 2 stacks, ~50 instructions, and 4GB flat address space (theoretically). I'm not sure that DOS 6.22 that I currently prefer can handle more than 64 MB of RAM. While I tried to keep instructionset simple, I was forced to put in lot of complex instructions to make it's performance acceptable on emulator. On actual silicon ~20 instructions is enaugh (I think).
Maybe one day similar system will run directly on custom silicon chip :)
CPU has following registers:
|DSP||data stack pointer|
|RSP||return stack pointer|
Virtual CPU, commands (most of them are avaiable as ordinary commands in programming lanquage):
code mnemonic description
0 nop does notheing
1 halt halt CPU ( return to DOS on emulator )
2 kbd@ ( – c ) read scancode of pressed or released key.
Returns 0, if no data avaiable.
3 num <dword> ( – n ) put immidiate number into datastack
4 jmp <dword> jump to specified code
5 call <dword>jump to specified code, save return address to
6 1+ ( n – n+1 )
7 1- ( n – n-1 )
8 dup ( n – n n ) duplicate top of data stack
9 drop ( n – ) drop last element in data stack
10 if <dword> ( n – ) jump to addr if top element was 0
11 ret jump to code, specified in return stack.
12 c@ ( addr – n ) read byte from memory at specified address
13 c! ( n addr – ) store byte to specified memory
14 push ( DSTK -> RSTK ) move top of datastack to returnstack
15 pop ( RSTK -> DSTK ) move top of returnstack to datastack
17 rot ( n1 n2 n3 – n2 n3 n1) rotate stack elements
18 disk@ ( FromDiskSect ToMem – ) read 1KB from disk into RAM
19 disk! ( FromMem ToDiskSect – ) write 1KB to disk
20 @ ( addr – n ) read 32 bit number from memory
21 ! ( n addr – ) store 32 bit number to memory
22 over ( n1 n2 – n1 n2 n1 ) self explaining …
23 swap ( n1 n2 – n2 n1 ) -,,-
24 + ( n1 n2 – n1+n2 ) -,,-
25 - ( n1 n2 – n1-n2 ) -,,-
26 * ( n1 n2 – n1*n2 ) -,,-
27 / ( n1 n2 – n1/n2 ) -,,-
28 > ( n1 n2 – result ) is true when n1 > n2
29 < ( n1 n2 – result ) is true when n1 < n2
30 not ( n1 – not_n1 ) logical not
31 i ( – n ) copies top of return stack into datastack
32 cprt@ ( addr – n ) read one byte from hardware port
33 cprt! ( n addr – ) store one byte to hardware port
34 i2 ( – n ) like "i" but takes socond top stack element.
35 i3 ( – n ) like "i" but takes third top stack element.
36 shl ( n amount – n ) left bit shift
37 shr ( n amount – n ) right bit shift
38 or ( n1 n2 – n ) logical or
39 xor ( n1 n2 – n ) exclusive logical or
40 vidmap ( addr – ) copy memory from "addr" to video memory.
41 mouse@ ( – x y button ) read mouse coordinates & buttons
42 vidput ( addr1 addr2 x y – ) put image1 into image2, at
location x, y. Does clipping, so part of a big image
can be mapped into smaller one.
43 cmove ( addr1 addr2 amount ) move memory from addr1 to addr2
if addr1 is greater than addr2 then count address
foward while moving, elseway starts from end and
counts backwards, so no data loss will occure on
44 cfill ( c addr amount – ) fill memory starting at "addr"
with "c" bytes.
45 tvidput ( addr1 addr2 x y – ) same as "vidput" but treats
color 255 in source image as transparent.
46 depth ( – depth ) returns current depth of data stack.
47 charput ( colorfg colorbg addrsrc addrdest x y )
draw character to image buffer located at "addrdest"
to specified x & y location. Decodes 8 bytes from
source to bits, used to draw character.
11 Fifth source format
Fifth uses a different character table and codes than ASCII (still almost similar). I call it FSCII (Fifth Standard Code for Information Interchange) for example space character is not 32 but 255 instead. I plan to use mainly HEX numbers, and create new characters to represent numeric values. So typical nemric characters "0123…" is treated like ordinary letters.
|0 - 15||0 - F||HEX numbers|
|254||FE||carriage return (CR)|
|else||ordinary characters, same as in ASCII.|
12 Fifth commands
12.1 Compilation & miscellaneous
init module ( – )
First module, control is passed to on startup. Contains
initialization routines. Also it is the last core module.
All new modules on top of it comes as result of executing
external source files.
head <name> ( – ) compiles new dictionary entry without specifying
new module type.
ex: head myentry
: <name> ( – ) creates new code module
; ( – ) ends module (immideate)
ex: : hello ." hi there" ;
const <name> ( n – ) defines new constant.
ex: 2147483647 const max
:i <name> ( – ) same as ":" but this module will be executed
immideately even in compile mode.
ex: :i ( 41 scan ;
create <name> ( – ) same as "head" , but specify module type as data.
ex: create LotoResults 5 , 13 , 52 , 12 , 11 , 3 ,
allot ( n – ) allocate n bytes in dictionary.
ex: create MyArray 100 allot
" <string>" ( – ) compile string and its size into core.
ex: create Mystring " This is it's contects"
str <name> <string>" ( – ) just shorter way for defining strings.
ex: str Mystring This is it's contenc"
var <name> ( – ) define new 32 bit variable.
ex: var result
' <module> ( – n ) return memory address of given entry.
ex: ' init
forget <name> ( – ) erases from RAM given entry and all entries what was
defined after it.
ex: forget myprog
[ ( – ) set interpret mode (immideate)
] ( n – ) set compile mode and compile top stack element
in as literal. Together [ …. ] cobination provides good
way to compute some values only once, at compile time,
rather than every time while program is running.
ex: : calculate - [ 4 MyConst1 + MyConst2 * ] ;
defer <name> ( – ) creates new module, with jump instruction.
Later address where to jump can be modified by "is" command.
This provides method of foward referencing. So you can use
modules what not jet exist.
is ( address1 address2 – ) address1 - where to jump, address2 -
address of module created by defer command.
ex: defer dispver
: run dispver ." running …" ;
… whatever …
: (dispver ." Version 9.99 " ;
' (dispver ' dispver is
Now if I type "run" on the screen appears:
Version 9.99 running …
asc <char> ( – ) reads char ascii code and treats it as literal.
ex: : BreakLine 30 do asc - emit loop ;
: BreakLine 30 do 45 emit loop ;
dyninc ( handle – ) execute code in dynamic memory handle.
automatically deallocates it when done.
include ( filenumber – ) execute code in specified file.
words ( – ) display existing blocks in core.
bye ( – ) exit from Fifth
fkey ( – c )
Read one byte from input stream.
sadd ( c addr – )
Add one byte "c" to string located at "addr" and updates
scan ( c – )
Read input stream and store it to pad until it finds c .
It ignores all "c" bytes until it finds any non "c" byte.
in other words:
c is: "
input stream: """"This is test !"aoeu idh
result: This is test !
Is useful for breaking text lines into words.
skey ( – c )
So called safe "fkey". Reads data from input stream
but converts characters with ASCII codes: 9 13 10
str=str? ( adr1 adr2 – result )
Compares string at "adr1" with string at "adr2", returns
true flag if they are equal or false if they are not.
true = -1
false = 0
find ( – addr )
Searches whole dictionary for word in "pad". If found,
returns it address, if not, returns 0.
execute ( – )
Execute word located in "pad". Depending on "mode".
dta ( addr – DataAddr )
Calculates address of dictionary entry data area, from
2num ( – num result )
Attempt to convert string located in "pad" into numeric
value. If succeed returns number and true as result.
If not, returns whatever and false as result.
dadd ( addr length – )
Add to dictionary data located at "addr", with specified
lit ( n – )
Act with number depending on "mode". When interpreting,
leaves it in stack.
incmod ( addr – )
Add to dictionary data located at "addr"+1 , length is taken
here ( – n )
return "h" contents.
mode var 8 bit
Holds input stream parser operation mode.
0 = interpreting
1 = compiling
pad var 128 bytes
Holds temprorary strings.
h var 32 bit
Pointer to free byte in memory, always at the end of the
dictionary. Each time when something is stored
by "c," command, pointer is incareased.
lp var 32 bit
Pointer to last dictionary word. Each time when new word is
compiled or erased by "forget", this pointer is updated.
modulechk ( Dstr<filename> – ) check if module is loaded, if not
immideately load it.
ne ( entrydata entrytype – ) Compile new dictionary entry.
It's name must be in "pad".
12.2 Conditionals & control flow
if ( flag – ) (immideate)
"if 1.. else 2.. then" or
"if 1.. then" construction. Conditional execution.
Performs "1.." if "flag" was true,
elseway performs "2.." if exist. Execution continues after
ex: 1 if ." nonzero" else ." zero" then
>= ( n1 n2 – result ) true if (n1 = n2) or (n1 > n2)
ex: 5 3 >= if ." first number is greater or equal" then
<= ( n1 n2 – result ) true if (n1 = n2) or (n1 < n2)
= ( n1 n2 – result ) true if n1 = n2
do ( count – ) (immideate)
"do .. loop" construction. Performs ".." "count" times.
In every step "count" is decareased until it is 0.
ex: : test 5 do i .d loop ;
result: 4 3 2 1 0
doexit ( – ) exit from "do .. loop"
for ( count top – ) (immideate)
"for .. loop" construction. Performs ".." (top - count) times.
In every step "count" is incareased until it reaches "top" .
ex: : test 4 10 for i .d loop ;
result: 4 5 6 7 8 9
forexit ( – ) exit from "for .. loop"
until ( – ) (immideate)
"until .. loop" construction. Performs ".." until flag become
true. False by default. Top of return stack holds flag.
done ( – ) exit from "until .. loop"
12.3 Disk & file access
diskload ( FromDisk ToMem amount – )
Load specified abount of bytes from disk into memory.
disksave ( FromMem ToDisk amount – )
save specified abount of bytes from memory into disk.
format ( – ) Erase all files.
fsDfilesize@ ( handle – size )
Return size of opened file.
fsDcurloc@ ( handle – location )
Return current location in file.
fsDupdated@ ( handle – updated? )
Return true if file was updated,
ie. write operations occured.
fssave ( FromMem DestFileHandle amount – )
Save data to file.
fsload ( SrcFileHandle ToMem amount – )
Load data from file.
fseof ( handle – bytesLeft )
Return amount of bytes left till end of file.
Useful before read operation.
fsls ( – ) List all files and lists (directories,folders)
in current path.
fslsr ( – ) Same as "fsls" but recursively scans also sub lists.
fscl ( DynStrHand – )
Change list (path)
fscreate ( DynStrHand – DescPnt )
Create new file or list. Can create multiple lists at once.
ex: when creating:
and only "\listGAMES\" already exist, then
"listSTRATEGY" and "listSIMWORLD" lists will be created,
and empty file "5th-runme" placed in there.
fsDsave ( DynHand<data> DynStrHand<filename> – )
Create new file and save all data from dynamic memory
block to it.
fsDload ( DynStr<SrcFileName> DynHand<DataDest> – )
Load whole file into dynamic memory block.
fsDloadnew ( DynStr<SrcFileName> – DynHand<DataDest> )
Load whole file into new dynamic memory block.
12.4 Dynamic memory
dynal ( size – handle )
Allocate dynamic memory block and return it's handle.
dynde ( handle – )
Deallocate dynamic memory block.
dynp ( handle – addr )
Returns pointer to memory where dynamic block
dyns ( handle – size )
Returns size of dynamic block.
dynresize ( NewSize handle – )
Nondestructively resize dynamic block.
dync@ ( addr handle )
Read one byte from dynamic block.
dync! ( byte addr dynhandle )
Write one byte to dynamic block.
dyn@ ( addr handle )
Read 32 bit number from dynamic block.
Address will spacify, whitch number, not byte.
dyn! ( 32BitNum addr dynhandle )
Write 32 bit number to dynamic block.
Address will spacify, whitch number, not byte.
dyncon ( size "name" – )
Allocate dynamic block with specified size, and
create constant honding its handle.
ex: 100 dyncon MyNewBlock
dyn. ( handle – )
Write contenc of dynamic memory block to screen.
12.5 Graphics and text
. ( n – ) print number on screen
d. ( n – ) print number on screen in decimal
? ( addr – ) print 32 bit value located at addr.
." <string>" ( – ) print string into screen. Immideately
ex: : greeting ." Hello, World" ;
tab. ( – ) print tabulator
calccol ( b g r – c ) calculate color what best matches given
Blue Green & Red values. Values must be in range 0 - 255.
imgalloc ( xsize ysize – imgbuf ) allocate image buffer for
imgsize ( imgbuf – ) print on the screen X & Y size of image
point ( x y imgbuf – addr ) returns memory address for specified
pset ( color x y imgbuf – ) set graphic point
boxf ( x1 x2 y1 y2 imgbuf color – ) draw filled box
cls ( imgbuf – ) clear image buffer
setpal ( b g r color – ) set palette value for specified color.
values bust be in size 0 - 63.
putchar ( char color x y imgbuf – ) put graphic character in
imagebuffer to specified (x & y) location.
scroll ( x y imgbuf – ) scroll in imgbuf.
scrollf ( color x y screen – ) scroll and fill empty space with
at! ( x y – ) set cursor location
curc! ( color – ) set text color
curb! ( solor – ) set backround color
colnorm ( – ) set text color to normal
colneg ( – ) set text color to negative (selected)
dyntype ( dynhandle – ) display contenc of dynamic memory on screen
fsdisp ( file – ) clear screen, display file, and wait for key
type ( addr length – )
Types on the screen string, from memory at addr and
write ( addr – )
Types on the screen string, from memory at "addr"+1
length is taken from "addr" .
screen const 32 bit
Holds handle of screen buffer.
copyscreen ( SrcImgHandle DestImgHandle – ) copy contenc of source
image to destination image. Source and destination images
must have same size.
12.6 Math, memory & stack manipulation
off ( n – ) writes 0 to given address, good for zeroing variable.
ex: MyVariable off
on ( n – ) writes -1 (true flag) to given address.
ex: MyVariable on
2dup ( n1 n2 – n1 n2 n1 n2 )
2drop ( n1 n2 – )
nip ( n1 n2 – n2 )
neg ( n1 – -n1 ) negotiate
bit@ ( n bit – result ) return specified bit from n.
ex: 38 2 bit@ (result will be 1)
to32bit ( n1 n2 n3 n4 – n32 ) treat 4 last stack elements as bytes
and unite them into 32 bit dword. Most significant byte
ex: 12 76 23 11 to32bit result: 186076172
to8bit ( n32 – n1 n2 n3 n4 ) break 32 bit number into 4 bytes.
Useful if you need to send 32 bit numbers thru 8 bit COM
ex: 186076172 to8bit result: 12 76 23 11
mod ( n1 n2 – reminder ) divide n1 by n2 and returns reminder.
ex: 12 5 mod result: 2
bound ( low n high – n ) check if n is in given bounds,
if not then incarease/decarease it to match bounds.
ex: 5 80 15 bound result: 15
5 10 15 bound result: 10
5 -10 15 bound result: 5
bound? ( low n high – result ) returns true if n is in the
tab ( col – spaces) calculate amount of spaces to add
ta reach next tabulation from given column.
count ( addr – addr+1 n )
Useful for returning bytes from constantly incareasing
address. Module "type" is nice example.
c, ( n – )
store one byte at memory specified by "h". And incarease
"h" by 1.
, ( n – )
store 32 bit number at memory specified by "h". And
incarease "h" by 4.
cmove ( addr1 addr2 n – )
copy "n" amount of bytes from memory at "addr1" to memory
rnd ( limit – result )
generates random number in range 0 to "limit"-1.
abs ( n – |n| )
returns absolute value of "n"
12.7 Dynamic & static strings
Fifth supports both static and dynamic strings. Static strings must have predefined space reserved, and string mustn't exceed this length. They manipulation is faster. But they use more memory. Static string memory address is used to refer to the string.
Dynamic strings can have at any time length form 0 to 0FFh, They take up only memory they currently need. They are held in dynamic memory blocks, so dynamic block handle is used to refer to this string.
Both types of strings are stored in the way, where first (0th) byte holds current string length, following bytes are string itself.
Dstral ( – handle )
Allocate new string.
Dstrlen ( handle – length )
Return string length.
c+Dstr ( chr handle – )
Add one byte to end of the string.
c+lDstr ( chr handle – )
Add one byte to left side (beginning) of the string.
Dstr. ( handle – )
Write contec of string into screen.
Dstrsure ( size Dstr – )
Makes sure that at least rquested
"size" (amount of characters) is allocated for given
Dstr2str ( handle address – )
Copy dyamic string into static memory space.
str2Dstr ( address handle – )
Copy static string into dyamic string.
Dstr+str ( Dstr addr – )
Add contenc of dynamic string to static string.
D" any string" ( – Dstr )
Moves specified string into dynamic string called "defDstr".
D> any_string ( – Dstr )
Moves specified string into dynamic string called "defDstr".
Space marks end of string!
D>2 any_string ( – Dstr )
Moves specified string into dynamic string called "defDstr2".
Space marks end of string!
Dstr+Dstr ( Dstr1 Dstr2 – )
Adds "Dstr1" to "Dstr2" and places result into "Dstr2".
Dstrclear ( Dstr – )
Clears contenc of dynamic string.
Dstr2Dstr ( Dstr1 Dstr2 – )
Moves "Dstr1" to "Dstr2".
Dstr ( data" name – )
Creates new dynamic string and moves specified data into it.
Then creates new constant with given "name" holding created
dynamic string handle.
ex: Dstr Hello, my name is Sven!" message \ creates it
message Dstr. \ tests it
Dstrlscan ( char Dstr – loc )
Searches dynamic string for "char", from left to right,
returns first found "char" location in string, or 0,
if not found.
Dstrrscan ( char Dstr – loc )
Searches dynamic string for "char", from right to left,
returns first found "char" location in string, or 0,
if not found.
Dstrlscane ( char Dstr – loc )
Same as "Dstrlscan" buf returns string length+1 as location.
Dstrleft ( amo Dstr – )
Only specified amount of characters from left remains
in dynamic string. ie. cut right part out.
Dstrright ( amo Dstr – )
Only specified amount of characters from right remains
in dynamic string. ie. cut left part out.
Dstrcutl ( amo Dstr – )
Cut specified amount of characters from left of dynamic
Dstrsp ( char Dstr1 Dstr2 – )
Separate dynamic string in Dstr1 into two parts,
using "char" as separator. First part will be stored in
"Dstr2", second part in "Dstr1".
ex: asc \ \ ..separator
D> listF\listLIB\5TH_DRVMOUSE \ ..separate from
defDstr2 \ ..place result in
Dstrsp \ separation command
defDstr Dstr. \ will be: listLIB\5TH_DRVMOUSE
defDstr2 Dstr. \ will be: listF
Dv ( addr – )
Allocates empty dynamic string, and places it's handle
into given address.
Df ( addr – )
Reads dynamic string handle from given address and
deallocates (frees) it.
ex: var mystring1
mystring1 Dv \ allocates string
mystring1 Df ; \ deallocates it again when no longer needed.
13 Dynamically loadable modules
13.1 Keyboard driver
KBD_@ ( – code ) get scancodes for pressed keys from keyboard.
KBD_down? ( key – result ) check is key with specified scancode
currently pressed down.
KBD_SC2FSCII ( code – FSCII ) convert key scancode into FSCII code,
or in FSK (Fifth standard keycode).
KBD_F@ ( – FSCII ) read pressed key FSCII or FSK, returns -1 if no
keys are pressed.
KBD_FW@ ( – FSCII ) read pressed key FSCII or FSK, if no keys is
are pressed then waits until there is.
401 … F1 …
13.2 Mouse driver
mousex var Mouse x coordinate.
mousey var Mouse y coordinate.
mousekeyl var Mouse left key.
mousekeym var Mouse middle key.
mousekeyr var Mouse right key.
mousec var Display current mouse coordinates in top left part of screen,
if true. (good for debugging)
mousepointer var Image buffer, holding current mouse pointer.
mouseadd ( ModuleAddr x1 x2 y1 y2 – ) Add specified area on screen,
into mause click buffer. If any mouse button is clicked on
that area, module at "ModuleAddr" will be executed.
mousebe var Amount of buffer elements.
mousedo ( – ) Updates mouse coordinates and keys. Parse mouse
click buffer, and draw mouse cursor to "screen".
13.3 2D graphic library
lineh ( color len x y imgbuf – ) draws horisontal line
from X,Y coordinates to right, with specified length.
linev ( color len x y imgbuf – ) draws vertical line
down, from coordinates X,Y, with specified length.
box ( color x2 x1 y2 y1 imgbuf – ) draws rectangular
box. x2 bust be >= x1, y2 must be >= y1.
flipv ( imgbuf – ) flip image vertically.
imgcoltrans ( ImgBuf Color ToColor – ) Translate all pixels in
specified image with "Color" into "ToColor".
imgfill ( color x y imgbuf – ) Fill image region starting at location
X & Y with specified color.
13.4 Trigonometry functions
sin ( a – result ) return sinus from given angle "a",
360ø is 2000. So 1000 represents 180ø angle.
Result will be in range -10'000 to 10'000, instead of ñ1.
cos ( a – result ) return cosinus from given angle.
Parameters are like in "sin" function.