     1                                  ; ****************************************************************************
     2                                  ; dropz.s (for TRDOS 386)
     3                                  ; ----------------------------------------------------------------------------
     4                                  ; DROPZ.PRG ! VGA DEMO program by Erdogan TAN
     5                                  ;
     6                                  ; 30/10/2017
     7                                  ;
     8                                  ; [ Last Modification: 05/12/2023 ] 
     9                                  ;
    10                                  ; Derived from source code of 'DROPZ.COM' ('dropz.asm') by baze/3SC
    11                                  ;				      (17/04/2000) 
    12                                  ; Assembler: NASM 2.15 (2.11)
    13                                  ; ----------------------------------------------------------------------------
    14                                  ;	   nasm  dropz.s -l dropz.txt -o DROPZ.PRG	
    15                                  ; ****************************************************************************
    16                                  
    17                                  ;-------------------------------------------------------------------------------
    18                                  ; dr()pz [refined], 256B intro, 1st place at Demobit 98 demoparty
    19                                  ; coded by -baze-> of 3SC [with help of bEETLE and loveC (many refinements)]
    20                                  ; e-mail: baze@decef.elf.stuba.sk
    21                                  ;-------------------------------------------------------------------------------
    22                                  ; This source code is written to be compiled by cool Netwide Assembler (NASM).
    23                                  ; Visit it's web site at www.web-sites.co.uk/nasm.
    24                                  ;-------------------------------------------------------------------------------
    25                                  ; And now few comments in worldwide used Slovak language :)
    26                                  
    27                                  ;------------------------------------------------------------------------------
    28                                  ; TRDOS 386, TRDOS v2.0
    29                                  ;------------------------------------------------------------------------------
    30                                  
    31                                  ; 14/07/2020
    32                                  ; 31/12/2017
    33                                  ; TRDOS 386 (v2.0) system calls
    34                                  _ver 	equ 0
    35                                  _exit 	equ 1
    36                                  _fork 	equ 2
    37                                  _read 	equ 3
    38                                  _write	equ 4
    39                                  _open	equ 5
    40                                  _close 	equ 6
    41                                  _wait 	equ 7
    42                                  _create	equ 8
    43                                  _rename	equ 9
    44                                  _delete	equ 10
    45                                  _exec	equ 11
    46                                  _chdir	equ 12
    47                                  _time 	equ 13
    48                                  _mkdir 	equ 14
    49                                  _chmod	equ 15
    50                                  _rmdir	equ 16
    51                                  _break	equ 17
    52                                  _drive	equ 18
    53                                  _seek	equ 19
    54                                  _tell 	equ 20
    55                                  _memory	equ 21
    56                                  _prompt	equ 22
    57                                  _path	equ 23
    58                                  _env	equ 24
    59                                  _stime	equ 25
    60                                  _quit	equ 26
    61                                  _intr	equ 27
    62                                  _dir	equ 28
    63                                  _emt 	equ 29
    64                                  _ldrvt 	equ 30
    65                                  _video 	equ 31
    66                                  _audio	equ 32
    67                                  _timer	equ 33
    68                                  _sleep	equ 34
    69                                  _msg    equ 35
    70                                  _geterr	equ 36
    71                                  _fpstat	equ 37
    72                                  _pri	equ 38
    73                                  _rele	equ 39
    74                                  _fff	equ 40
    75                                  _fnf	equ 41
    76                                  _alloc	equ 42
    77                                  _dalloc equ 43
    78                                  _calbac equ 44
    79                                  _dma	equ 45		
    80                                  
    81                                  %macro sys 1-4
    82                                      ; 29/04/2016 - TRDOS 386 (TRDOS v2.0)	
    83                                      ; 03/09/2015	
    84                                      ; 13/04/2015
    85                                      ; Retro UNIX 386 v1 system call.	
    86                                      %if %0 >= 2   
    87                                          mov ebx, %2
    88                                          %if %0 >= 3    
    89                                              mov ecx, %3
    90                                              %if %0 = 4
    91                                                 mov edx, %4   
    92                                              %endif
    93                                          %endif
    94                                      %endif
    95                                      mov eax, %1
    96                                      ;int 30h
    97                                      int 40h ; TRDOS 386 (TRDOS v2.0)	   
    98                                  %endmacro
    99                                  
   100                                  ; TRDOS 386 (and Retro UNIX 386 v1) system call format:
   101                                  ; sys systemcall (eax) <arg1 (ebx)>, <arg2 (ecx)>, <arg3 (edx)>
   102                                  
   103                                  ;------------------------------------------------------------------------------
   104                                  ; CODE
   105                                  ;------------------------------------------------------------------------------
   106                                  
   107                                  [BITS 32]
   108                                  [org 0]
   109                                  
   110                                  Start:
   111                                  	; clear bss
   112 00000000 B9[00100200]            	mov	ecx, EOF
   113 00000005 BF[9A010000]            	mov	edi, bss_start
   114 0000000A 29F9                    	sub	ecx, edi
   115 0000000C C1E902                  	shr	ecx, 2
   116 0000000F 31C0                    	xor	eax, eax
   117 00000011 F3AB                    	rep	stosd
   118                                  
   119 00000013 56                      	push	esi		; naplnime niecim zasobnik pre nahodne cisla
   120 00000014 56                      	push	esi
   121                                  
   122 00000015 B013                    	mov	al, 13h
   123                                  	;int	10h		; inicializacia grafickeho modu 320x200x256
   124 00000017 CD31                    	int	31h
   125                                  
   126                                  	; DIRECT VGA MEMORY ACCESS
   127                                  	; bl = 0, bh = 5
   128                                  	; Direct access/map to VGA memory (0A0000h)
   129                                  
   130                                  	sys	_video, 0500h
    82                              <1> 
    83                              <1> 
    84                              <1> 
    85                              <1> 
    86                              <1>  %if %0 >= 2
    87 00000019 BB00050000          <1>  mov ebx, %2
    88                              <1>  %if %0 >= 3
    89                              <1>  mov ecx, %3
    90                              <1>  %if %0 = 4
    91                              <1>  mov edx, %4
    92                              <1>  %endif
    93                              <1>  %endif
    94                              <1>  %endif
    95 0000001E B81F000000          <1>  mov eax, %1
    96                              <1> 
    97 00000023 CD40                <1>  int 40h
   131 00000025 3D00000A00              	cmp	eax, 0A0000h
   132                                  	;jne	ENDPROG
   133 0000002A 7405                    	je	short _x
   134 0000002C E9FA000000              	jmp	ENDPROG
   135                                  _x:
   136                                  
   137                                  ; VYPOCET PALETY FARIEB
   138                                  
   139 00000031 B100                    	mov	cl, 0		; do CL hodnota "256" (CH = ?, minus 1 byte)
   140                                  PALETTE:
   141 00000033 66BAC803                	mov	dx, 3C8h	; do DX port PEL ADDRESS registra
   142 00000037 88C8                    	mov	al, cl
   143                                  	;out	dx, al		; odoslanie indexu farby
   144 00000039 B401                    	mov	ah, 1	
   145 0000003B CD34                    	int	34h
   146 0000003D 42                      	inc	edx		; do DX port PEL DATA registra
   147 0000003E B000                    	mov	al, 0
   148                                  	;out	dx, al		; odoslanie zlozky R
   149 00000040 CD34                    	int	34h
   150 00000042 88C8                    	mov	al, cl
   151 00000044 D0E8                    	shr	al, 1                                             
   152                                  	;out	dx, al		; odoslanie zlozky G
   153 00000046 CD34                    	int	34h
   154 00000048 88C8                    	mov	al, cl
   155 0000004A 3C40                    	cmp	al, 64
   156 0000004C 7202                    	jb	short OKPAL
   157                                  	;mov	ax, 4A3Fh	; do AH cislo DOS sluzby na realokaciu pamate
   158 0000004E B03F                    	mov	al, 3Fh
   159                                  OKPAL:
   160                                  	;out	dx, al		; odoslanie zlozky B
   161                                  	;mov	ah, 1
   162 00000050 CD34                    	int	34h
   163                                  	;loop	PALETTE		; opakujeme pre vsetky farby
   164 00000052 FEC9                    	dec	cl
   165 00000054 75DD                    	jnz	short PALETTE
   166                                  
   167                                  ; ALOKACIA PAMATE POTREBNEJ PRE DVE 256 x 256 PIXELOVE MAPY
   168                                  
   169                                  ;	;mov	ah, 4Ah
   170                                  ;	mov	bh, 3*16	; do BX aspon 3*16*256 paragrafov (BL = ?, -1B)
   171                                  ;	int	21h		; alokujeme 3 segmenty (program + 2 mapy)
   172                                  ;	jc	near ENDPROG	; ak je malo pamate, ukoncime program
   173                                  
   174                                  ;	mov	ax, cs
   175                                  ;	add	ah, 16
   176                                  ;	mov	ds, ax		; do DS segmentova adresa prvej mapy
   177                                  ;	add	ah, 16
   178                                  ;	mov	es, ax		; do ES segmentova adresa druhej mapy
   179                                  
   180 00000056 BA[00100000]            	mov	edx, DrawSegment ; *
   181 0000005B BD[00100100]            	mov	ebp, EffectSegment ; *	
   182                                  
   183                                  ; VYPIS BITMAPOVEHO TEXTU
   184                                  
   185                                  WATER:
   186                                  	;push	ebp ; ***
   187 00000060 52                      	push	edx ; ***
   188                                  	
   189                                  	;push	es		; ulozime ES (budeme potrebovat pointer na mapu)
   190                                  	;mov	ax, 1130h	; sluzba VGA BIOS - informacie o fonte
   191 00000061 B830110000              	mov	eax, 1130h
   192                                  	;mov	bh, 3		; budeme pouzivat font 8 x 8 pixelov
   193                                  	;int	10h		; v ES:BP je adresa fontu
   194 00000066 BB01000000              	mov	ebx, 1	; VGA Font 8x8
   195                                  	;xor	ecx, ecx 
   196 0000006B BA[9A010000]            	mov	edx, VgaFont8Buffer
   197 00000070 CD31                    	int	31h
   198                                  
   199 00000072 5A                      	pop	edx ; ***
   200                                  	;pop	ebp ; ***
   201                                  
   202 00000073 BB[70010000]            	mov	ebx, TEXT	; ideme "virit hladinu" textom
   203 00000078 BE26400000              	mov	esi, 64*256+38	; do SI umiestnenie textu v mape
   204 0000007D E8B8000000              	call	DRAWTEX		; zavolame vypis znakoveho retazca
   205 00000082 BE64640000              	mov	esi, 100*256+100
   206 00000087 E8AE000000              	call	DRAWTEX		; a to celkovo 3 krat
   207 0000008C BE24880000              	mov	esi, 136*256+36
   208 00000091 E8A4000000              	call	DRAWTEX
   209                                  
   210                                  	;pop	es		; obnovime pointer na pixelovu mapu
   211                                  
   212                                  ; "KVAPNUTIE" NA HLADINU
   213                                  
   214                                  RANDOM:
   215 00000096 5E                      	pop	esi		; nahodne cisla x[n] = (5 * x[n-1] + 7) % 65536
   216 00000097 668D74B607              	lea	si, [esi+4*esi+7]; takto pocita uvedeny vyraz loveC :)
   217 0000009C C60432FF                	mov	byte [edx+esi], 255 ; umiestnime na nahodne miesto mapy kvapku
   218 000000A0 56                      	push	esi		; ulozime nahodne cislo do buducej iteracie
   219                                  
   220                                  ; VYPOCET SIRENIA VLNENIA V MAPE (nemam miesto na odvodenie vztahov z fyziky)
   221                                  	
   222                                  WATLINE:
   223 000000A1 8A443A01                	mov	al, [edx+edi+1]
   224 000000A5 02443AFF                	add	al, [edx+edi-1]	; spocitame okolite pixely
   225 000000A9 02843A00010000          	add	al, [edx+edi+256]
   226 000000B0 02843A00FFFFFF          	add	al, [edx+edi-256]
   227 000000B7 D0E8                    	shr	al, 1		; vydelime sucet dvoma
   228 000000B9 2A443D00                	sub	al, [ebp+edi]	; odcitame predchadzajucu fazu
   229 000000BD 7302                    	jnc	short OK	; pripadne orezeme zaporne vlny ...
   230 000000BF B000                    	mov	al, 0		; ... ziskame tak vacsiu amplitudu (0 - 255)
   231                                  OK:
   232                                  	;stosb			; ulozime pixel
   233 000000C1 88443D00                	mov	[ebp+edi], al
   234 000000C5 6647                    	inc	di
   235 000000C7 6609FF                  	or	di, di
   236 000000CA 75D5                    	jnz	short WATLINE	; opakujeme pre vsetky pixely v mape
   237                                  
   238                                  	;push	ds		; ulozime DS (neskor POPneme do ES)
   239 000000CC 52                      	push	edx ; *(*)
   240                                  	;push	es
   241                                  	;pop	ds		; do DS hodnota ES (vymena pointrov na mapy)
   242                                  	;mov	edx, ebp ; **
   243                                  	;push	word 0A000h
   244                                  	;pop	es		; do ES segmentova adresa zaciatku videoram
   245                                  
   246                                  ; CAKANIE NA NOVY SNIMOK
   247                                  
   248                                  FRAME:
   249 000000CD 66BADA03                	mov	dx, 3DAh	; do DX port INPUT STATUS registra (DH = 3, -1B)
   250 000000D1 B400                    	mov	ah, 0
   251                                  	;in	al, dx
   252 000000D3 CD34                    	int	34h
   253 000000D5 2408                    	and	al, 8
   254 000000D7 74F4                    	jz	short FRAME	; pockame na novy snimok
   255                                  
   256                                  ; VYKRESLENIE MAPY NA OBRAZOVKU
   257 000000D9 89EA                    	mov	edx, ebp ; **
   258                                  
   259 000000DB BF20000000              	mov	edi, 32		; budeme vykreslovat od 32. stlpca (centrovanie)
   260 000000E0 31F6                    	xor	esi, esi	; do SI zaciatok vykreslovanej mapy
   261 000000E2 BDC8000000              	mov	ebp, 200	; kreslime 200 riadkov
   262                                  DRAW:
   263 000000E7 B180                    	mov	cl, 128		; prenasame 256 bajtov, cize 128 slov (word)
   264                                  	;rep	movsw		; prenos slov z mapy do videoram (rychlejsie)
   265                                  draw_loop:
   266 000000E9 668B0432                	mov	ax, [edx+esi]
   267 000000ED 66898700000A00          	mov	[edi+0A0000h], ax
   268 000000F4 6683C602                	add	si, 2
   269 000000F8 6683C702                	add	di, 2
   270 000000FC E2EB                    	loop	draw_loop	
   271 000000FE 0FB61C32                	movzx	ebx, byte [edx+esi] ; vyberieme hodnotu z mapy kvoli "osciloskopu"
   272 00000102 08DB                    	or	bl, bl		; je vyska hladiny v mape nulova? ...
   273 00000104 7412                    	jz	short NOOSCIL	; ... ak ano, nevykreslujeme pixel (estetika)
   274 00000106 C6843B80FF090050        	mov	byte [ebx+edi+0A0000h-128], 80	; inak vykreslime symetricky dva pixely
   275 0000010E F7DB                    	neg	ebx		; s danou intenzitou
   276 00000110 C6843B80FF090050        	mov	byte [ebx+edi+0A0000h-128], 80
   277                                  NOOSCIL:
   278 00000118 6683C740                	add	di, 64		; posunieme sa na dalsi riadok obrazovky
   279 0000011C 4D                      	dec	ebp
   280 0000011D 75C8                    	jnz	short DRAW	; a opakujeme pre vsetky riadky
   281                                  
   282                                  	;pop	es		; dokoncenie vymeny ES <-> DS
   283 0000011F 5D                      	pop	ebp ; *(*)
   284                                  
   285                                  	;push	edx ; ****
   286                                  	;;in	al, 60h		; test klavesy ESC
   287                                  	;mov	dx, 60h
   288                                  	;;mov	ah, 0
   289                                  	;int	34h
   290                                  	;pop	edx ; ****
   291                                  	;dec	al
   292                                  	;jnz	WATER		; ak nebola stlacena, skok na dalsi snimok
   293                                  
   294 00000120 B401                    	mov	ah, 1
   295 00000122 CD32                    	int	32h
   296                                  	;jz	WATER
   297 00000124 7505                    	jnz	short ENDPROG
   298 00000126 E935FFFFFF              	jmp	WATER
   299                                  
   300                                  ENDPROG:
   301 0000012B 66B80300                	mov	ax, 03h
   302                                  	;mov	al, 3
   303                                  	;int	10h		; nastavenie textoveho rezimu
   304 0000012F CD31                    	int	31h
   305                                  
   306 00000131 5E                      	pop	esi
   307 00000132 5E                      	pop	esi		; oprava zasobnika po nahodnych cislach
   308                                  
   309                                  	sys	_exit		; navrat do operacneho systemu
    82                              <1> 
    83                              <1> 
    84                              <1> 
    85                              <1> 
    86                              <1>  %if %0 >= 2
    87                              <1>  mov ebx, %2
    88                              <1>  %if %0 >= 3
    89                              <1>  mov ecx, %3
    90                              <1>  %if %0 = 4
    91                              <1>  mov edx, %4
    92                              <1>  %endif
    93                              <1>  %endif
    94                              <1>  %endif
    95 00000133 B801000000          <1>  mov eax, %1
    96                              <1> 
    97 00000138 CD40                <1>  int 40h
   310                                  
   311                                  ; RUTINA NA VYPIS TEXTOVEHO RETAZCA
   312                                  
   313                                  DRAWTEX:
   314 0000013A 0FB63B                  	movzx	edi, byte [ebx]	; do DI ASCII hodnota znaku
   315 0000013D 43                      	inc	ebx		; zvysime ukazovatel na text
   316 0000013E C1E703                  	shl	edi, 3		; DI = DI * 8, mame offset znaku vo fonte
   317 00000141 742C                    	jz	short RETURN	; ak bol znak nulovy, koniec vypisu
   318 00000143 B108                    	mov	cl, 8		; budeme vypisovat 8 riadkov
   319                                  CHARLIN:
   320 00000145 8A87[9A010000]          	mov	al, [VgaFont8Buffer+edi] ; vyberieme bajt z predlohy znaku
   321 0000014B 47                      	inc	edi		; zvysime ukazovatel na dalsi bajt predlohy
   322 0000014C B508                    	mov	ch, 8		; znak ma 8 stlpcov
   323                                  ROTATE:
   324 0000014E D0E0                    	shl	al, 1		; do CARRY pixel z predlohy
   325 00000150 7307                    	jnc	short NOPIXEL	; ak pixel nebol nastaveny, nic nekreslime
   326 00000152 81043204030402          	add	dword [edx+esi], 02040304h ; inak pripocitame "stvorpixel"
   327                                  NOPIXEL:
   328 00000159 6683C604                	add	si, 4		; posunieme sa na dalsi pixel v mape
   329 0000015D FECD                    	dec	ch
   330 0000015F 75ED                    	jnz	short ROTATE	; opakujeme 8-krat
   331 00000161 6681C6E003              	add	si, 1024-32	; posunieme sa na dalsi riadok
   332 00000166 E2DD                    	loop	CHARLIN		; opakujeme 8-krat (LOOP trik, CH = 0, setrime)
   333 00000168 6681C620E0              	add	si, 32-8192	; posunieme sa na dalsi znak
   334 0000016D EBCB                    	jmp	short DRAWTEX	; skok na vypis dalsieho znaku
   335                                  RETURN:
   336 0000016F C3                      	retn
   337                                  
   338                                  ;------------------------------------------------------------------------------
   339                                  ; DATA
   340                                  ;------------------------------------------------------------------------------
   341                                  
   342                                  TEXT:
   343 00000170 64722829707A00          	db	"dr()pz", 0	; hadajte co :)
   344 00000177 627900                  	db	"by",0
   345 0000017A 2D62617A653E00          	db	"-baze>", 0
   346                                  
   347                                  ;-------------------------------------------------------------------------------
   348                                  ; Initially, this intro was hacked up during sleepless night before party.
   349                                  ; Few days after Demobit 98 we made this refined version. Although it is not
   350                                  ; as carefully optimized as it can be [loveC was able to make it in less than
   351                                  ; 230 bytes], I decided to spread this [almost original] code. It is easier
   352                                  ; to understand and it actually shows our poor mental state at given time :)
   353                                  ;-------------------------------------------------------------------------------
   354                                  
   355                                  ;db	"Erdogan Tan [01/11/2017]"
   356 00000181 4572646F67616E2054-     db	"Erdogan Tan [05/12/2023]", 0
   356 0000018A 616E205B30352F3132-
   356 00000193 2F323032335D00     
   357                                  
   358                                  ;------------------------------------------------------------------------------
   359                                  ; UNINITIALIZED DATA
   360                                  ;------------------------------------------------------------------------------
   361                                  
   362                                  bss_start:
   363                                  
   364                                  ABSOLUTE bss_start
   365                                  
   366                                  alignb 2 
   367                                  
   368                                  VgaFont8Buffer:
   369 0000019A <res 800h>              	resb	8*256
   370                                  
   371                                  ;alignb	65536
   372 0000099A <res 666h>              alignb 4096
   373                                  
   374                                  DrawSegment:
   375 00001000 <res 10000h>            	resb	65536
   376                                  
   377                                  EffectSegment:
   378 00011000 <res 10000h>            	resb  	65536
   379                                  
   380                                  EOF:
