Fifth - virtual machine, operating system, programming language
+Table of Contents
+-
+
- 1. General + + +
- 2. !Project deprecated! +
- 3. Introduction + + +
- 4. Installation +
- 5. Fifth distribution directory tree description +
- 6. Requirements + + +
- 7. Numbers representation within Fifth +
- 8. Disk file map, and it's data structures + + +
- 9. Core architecture + + +
- 10. Dynamically loadable modules + + +
1. General
+-
+
- This program is free software: released under Creative Commons Zero +(CC0) license + +
- Program author:
+
-
+
- Svjatoslav Agejenko +
- Homepage: https://svjatoslav.eu +
- Email: mailto://svjatoslav@svjatoslav.eu +
+
+ - Other software projects hosted at svjatoslav.eu +
1.1. Source code
+-
+
- Download latest snapshot in TAR GZ format + +
- Browse Git repository online + +
+Clone Git repository using command: +
++git clone https://www2.svjatoslav.eu/git/fifth.git +
+
2. !Project deprecated!
++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.
-
-
-Screenshots
-
-Read more about:
-
Virtual CPU
-
Built-in commands
-
Additional commands, realized as loadable modules
-
Example Fifth source file - text editor
-
-
-
Installation
- +Sixth. + + ++System is built many years ago when I was still using DOS as a primary +operating system. +
+3. Introduction
++Fifth is a combination of: +
+-
+
- Programming language (inspired by Forth). +
- Operating system. +
- Virtual machine with custom instruction set. +
3.1. Screenshots
+
+
+Startup screen diplaying Fifth logo and full file list. +
+ + +
+
+Sample words defined. Most of the words are commands that can be +executed interactively from the command line or from a file. When +executed, they can be selectively compiled or interpreted. +
+ + + +
+
+Built in text editor. +
+4. Installation
+Just unpack all files, witout altering original directory structure, -somewhere in your hard disk. For example: C:\MISC\FIFTH\.... -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. - - - -
Software/Hardware/Human requirements
- - -Software: - 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). - -Hardware: - Minimum CPU 386. - 64 KB free RAM below 640KB, - 2 MB of free XMS. - VESA compatible video card. - -Human: - Beginner level Forth knowledge is recommended. - Enthusiasm. - - - -Numbers representation
- -
-
-Fifth uses hexdecimal number representation as primary.
-Numbers shape is formed by dividing a square into four parts.
-And manipulating their color (black or white).
-
-
-
- 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. - - disk allocation: - -offset length description - -0 ~4 Kb Fifth core -4 Kb ~32Kb high-level boot code -37 Kb ~65Kb FAT -101Kb ~16MB filesystem data area - - FAT entry format: - --2 last sector --1 empty sector -0 -- .. pointer to next block - - file entry format - -offset length description - -0 4 extension -4 16 name -20 4 entry point -24 4 size -28 4 last modification time - - - -Core architecture
- - +somewhere in your hard disk. For example: + + ++C:\MISC\FIFTH\ ++ + +
+To run fifth you need minimally just 2 files: +
+-
+
- EMULATOR.COM
- Virtual CPU emulator +
- DISK.RAW
- Virtual disk file +
+For more information, please refer to Fifth distribution directory +tree description. +
+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. Requirements
+6.1. Software
+-
+
- MS-DOS 6.22 with HIMEM.SYS loaded. +
- Mouse driver (optional, if you have a mouse). +
- CPU is initialized into Unreal Mode during operation. +
- To recompile ASM sources, you can use FASM (Flat Assembler). +
- To run Quick Basic utilities, use Microsoft Quick Basic 4.5. +
- VESA support through BIOS or external driver (UNIVBE). +
6.2. Hardware
+-
+
- A minimum of a i386 CPU. +
- 64 KB of free RAM below 640KB. +
- 2 MB of free extended memory. +
- A VESA-compatible video card. +
7. Numbers representation within Fifth
++Because we are in full experimentation mode here (no regard for +compatibility whatsoever), why not to try also alternative number +representation ? +
+ ++Here alternative hexadecimal number representation format is devised: +
+ + +
+
+Essentially square is split into 4 triangles. Each triangle represents +one bit. +
+ ++Fifth uses this hexadecimal format as primary throughout entire +system. +
+ ++See also: Bibi-binary. +
+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
+| offset | +length | +description | +
|---|---|---|
| 0 | +~4 Kb | +Fifth core | +
| 4 Kb | +~32 Kb | +high-level boot code | +
| 37 Kb | +~65 Kb | +FAT | +
| 101 Kb | +~16 MB | +filesystem data area | +
8.2. FAT entry format:
+| code | +meaning | +
|---|---|
| -2 | +last sector | +
| -1 | +empty sector | +
| 0 -- | +.. pointer to next block | +
8.3. File entry format
+| offset | +length | +description | +
|---|---|---|
| 0 | +4 | +extension | +
| 4 | +16 | +name | +
| 20 | +4 | +entry point | +
| 24 | +4 | +size | +
| 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.
-
-
- dictionary entry format
-
-offset length description
-
-0 4 0 < previous entry
- 0 = last
- -1 = empty
-4 15 module name string
-19 1 entry type
-20 4 entry data
-
-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.
-
- Possible module types
-
-type description "execute" action
-
-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
-
-
- Memory map: (average)
-
-Fifth source format
-
-
-Fifth uses a different character table and codes than ASCII.
-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.
-
- FSCII:
-
-DEC HEX function
-
-0 - 15 0 - F HEX numbers
-252 FC backspace
-253 FD tabulator (TAB)
-254 FE carriage return (CR)
-255 FF space
-
-else ordinary characters, like in ASCII.
-
-
-
-
-
-
+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
+| offset | +length | +description | +
|---|---|---|
| 0 | +4 | +0 < previous entry | +
| + | + | 0 = last | +
| + | + | -1 = empty | +
| 4 | +15 | +module name string | +
| 19 | +1 | +entry type | +
| 20 | +4 | +entry data | +
+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
+| type | +description | +"execute" action | +
|---|---|---|
| 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
+| location | +size | +description | +
|---|---|---|
| 0 | +~4096 | +core | +
| 1500000 | +~32000 | +highlevel Fifth boot code | +
| 200000h | ++ | core startup messages area | +
| 5200000 | ++ | end of dynamic memory space | +
10. Dynamically loadable modules
+10.1. 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.
+
+ FSK
+ —
+In HEX.
+
+FC backspace
+FD TAB
+FE enter
+FF space
+
+400 ESC
+401 … F1 …
+410 up
+411 right
+412 down
+413 left
+414 INS
+415 DEL
+416 home
+417 end
+418 PG/UP
+419 PG/DN
+
10.2. 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".
+
10.3. 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. +
+ ++x1,y1-----------+ + | | + | | + +-----------x2,y2 +
+
+- 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. +
10.4. Trigonometry functions
+10.4.1. 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. +
+10.4.2. cos ( a – result )
++Return cosinus from given angle. Parameters are like in sin function. +
+