VGA Mode-X ÕÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͸ ³ W E L C O M E ³ ³ To the VGA Trainer Program ³ ³ ³ By ³ ³ ³ DENTHOR of ASPHYXIA ³ ³ ³ ÔÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ; ³ ³ ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ ³ ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÙ --==[ PART 10 ]==-- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ Introduction Wow! The trainer has finally reached part 10! This will also be the first part introduced simultaneously to local BBS's and the INTERNET at the same time! Yes folks, I put up a copy of previous tutorials onto various ftp sites, and awaited the flames saying that the net.gurus already knew this stuff, and why was I wasting disk space! The flames did not appear (well, except for one), and I got some messages saying keep it up, so from now on I will upload all future trainers to ftp sites too (wasp.eng.ufl.edu , cs.uwp.edu etc.). I will also leave a notice in the USENET groups comp.lang.pascal and comp.sys.ibm.pc.demos when a new part is finished (Until enough people say stop ;-)) I can also be reached at my new E-Mail address, smith9@batis.bis.und.ac.za Well, this tutorial is on Chain-4. When asked to do a trainer on Chain-4, I felt that I would be walking on much travelled ground (I have seen numerous trainers on the subject), but the people who asked me said that they hadn't seen any, so could I do one anyway? Who am I to say no? The sample program attached isn't that great, but I am sure that all you people out there can immediately see the potential that Chain-4 holds. If you would like to contact me, or the team, there are many ways you can do it : 1) Write a message to Grant Smith/Denthor/Asphyxia in private mail on the ASPHYXIA BBS. 2) Write to Denthor, EzE or Goth on Connectix. 3) Write to : Grant Smith P.O.Box 270 Kloof 3640 Natal South Africa 4) Call me (Grant Smith) at (031) 73 2129 (leave a message if you call during varsity). Call +27-31-73-2129 if you call from outside South Africa. (It's YOUR phone bill ;-)) 5) Write to smith9@batis.bis.und.ac.za in E-Mail. NB : If you are a representative of a company or BBS, and want ASPHYXIA to do you a demo, leave mail to me; we can discuss it. NNB : If you have done/attempted a demo, SEND IT TO ME! We are feeling quite lonely and want to meet/help out/exchange code with other demo groups. What do you have to lose? Leave a message here and we can work out how to transfer it. We really want to hear from you! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ What is Chain-4? You people out there all have at least 256k vga cards. Most of you have 512k vga cards, and some have 1MB vga cards. But what you see on your screen, as discussed in previous trainers, is 64k of data! What happened to the other 192k??? Chain-4 is a method of using all 256k at one time. The way this is done is simple. 1 screen = 64k. 64k * 4 = 256k. Therefore, chain-4 allows you to write to four screens, while displaying one of them. You can then move around these four screens to see the data on them. Think of the Chain-4 screen as a big canvas. The viewport, the bit you see out of, is a smaller rectangle which can be anywhere over the bigger canvas. +----------------------------+ Chain-4 screen | +--+ | | | | <- Viewport | | +--+ | | | +----------------------------+ =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ The size of the chain-4 screen The Chain-4 screen, can be any size that adds up to 4 screens. For example, it can be 4 screens across and one screen down, or one screen across and 4 screens down, or two screens across and two screens down, and any size in between. In the sample program, the size is a constant. The size * 8 is how many pixels across there are on the chain-4 screen, ie Size = 40 = 320 pixels across = 1 screen across, 4 screens down Size = 80 = 640 pixels across = 2 screens across, 2 screens down etc. We need to know the size of the screen for almost all dealings with the Chain-4 screen, for obvious reasons. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ Layout of the chain-4 screen, and accessing it If you will remember all the way back to Part 1 of this series, I explained that the memory layout of the MCGA screen is linear. Ie, the top left hand pixel was pixel zero, the one to the right of it was number one, the next one was number two etc. With Chain-4, things are very different. Chain-4 gets the 4 screens and chains them together (hence the name :)). Each screen has a different plane value, and must be accessed differently. The reason for this is that a segment of memory is only 64k big, so that we could not fit the entire Chain-4 screen into one segment. All Chain-4 screens are accessed from $a000, just like in MCGA mode. What we do is, before we write to the screen, find out what plane we are writing to, set that plane, then plot the pixel. Here is how we find out how far in to plot the pixel and what plane it is on : Instead of the linear model of MCGA mode, ie : ÚÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄ¿ ³00³01³02³03³04³05³06³07³08³09³10³11³ ... Each plane of the Chain-4 screen accesses the memory in this way : Plane 0 : ÚÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄ¿ ³00³ ³ ³ ³01³ ³ ³ ³02³ ³ ³ ³ ... Plane 1 : ÚÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄ¿ ³ ³00³ ³ ³ ³01³ ³ ³ ³02³ ³ ³ ... Plane 2 : ÚÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄ¿ ³ ³ ³00³ ³ ³ ³01³ ³ ³ ³02³ ³ ... Plane 3 : ÚÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄÂÄÄ¿ ³ ³ ³ ³00³ ³ ³ ³01³ ³ ³ ³02³ ... In this way, by choosing the right plane to write to, we can access all of the 256k of memory available to us. The plane that we write to can easily be found by the simple calculation of x mod 4, and the x coordinate is also found by x div 4. We work out our y by multiplying it by the size of our chain-4 screen. NOTE : It is possible to write to all four planes at once by setting the correct port values. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ Uses of Chain-4 The uses of Chain-4 are many. One could write data to one screen, then flip to it (the move_to command is almost instantaneous). This means that 64k of memory does not need to be set aside for a virtual screen, you are using the vga cards memory instead! Scrolling is much easier to code for in Chain-4 mode. It is possible to "tweak" the mode into other resolutions. In our demo, our vectors were in 320x240 mode, and our dot vectors were in 320x400 mode. The main disadvantage of chain-4 as I see it is the plane swapping, which can be slow. With a bit of clever coding however, these can be kept down to a minimum. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ The sample programs The first sample program is GFX.PAS. This is a until in which I have placed most of our routines from previous tuts. All the procedures and variables you can see under the INTERFACE section can be used in any program with GFX in the USES clause. In other words, I could do this : USES GFX,crt; BEGIN Setupvirtual; cls (vaddr,0); Shutdown; END. This program would compile perfectly. What I suggest you do is this : Rename the file to a name that suites you (eg your group name), change the first line of the unit to that name, then add all useful procedures etc. to the unit. Make it grow :-). The second file is the sample program (note the USES GFX,crt; up near the top!). The program is easy to understand and is documented. The bit that I want to draw your attention to is the constant, BIT. Because I am distributing this file to many places in text form, not binary form, I could not just add a .CEL file with the program. So what I did was write some text in one color then saved it as a .CEL . I then wrote a ten line program that did the following : Moving from left to right, it counted how many pixels were of color zero, then saved the byte value to an array. When it came across color one, is counted for how long that went on then saved the byte value and saved it to an array and so on. When it was finished, I converted the array into a text file in the CONST format. Not too cunning, but I thought I had better explain it ;-) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= þ In closing There are other documents and sample programs available on Chain-4 and it's like : Try XLIB for one... Finally! Some BBS's have joined my BBS list! (Okay, only two new ones, but it's a start ;-)) All you international BBS's! If you will regularly download the tuts from an FTP site, give me your names! I own a car. The car's name is Bob. A few days ago, Bob was in an accident, and now has major damage to his front. Knowing insurance, I probably won't get much, probably nothing (the other guy wasn't insured, and I am only 18 :( ). I will probably have to find work in order to pay for my repairs. The point to this meandering is this : I am upset, so if you think you are getting a quote, you can just forget it. Oh, well. Life goes on! See you next time, - Denthor These fine BBS's carry the ASPHYXIA DEMO TRAINER SERIES : (alphabetical) ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍËÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍËÍÍÍÍÍËÍÍÍËÍÍÍÍËÍÍÍÍ» ºBBS Name ºTelephone No. ºOpen ºMsgºFileºPastº ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÎÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÎÍÍÍÍÍÎÍÍÍÎÍÍÍÍÎÍÍÍ͹ ºASPHYXIA BBS #1 º(031) 765-5312 ºALL º * º * º * º ºASPHYXIA BBS #2 º(031) 765-6293 ºALL º * º * º * º ºConnectix BBS º(031) 266-9992 ºALL º º * º * º ºPOP! º(012) 661-1257 ºALL º º * º * º ºPure Surf BBS º(031) 561-5943 ºA/H º º * º * º ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÊÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÊÍÍÍÍÍÊÍÍÍÊÍÍÍÍÊÍÍÍͼ For international users : If you live outside the Republic of South Africa, do the following : Dial +27, dont dial the first 0, but dial the rest of the number. Eg, for the ASPHYXIA BBS : +27-31-765-5312 Open = Open at all times or only A/H Msg = Available in message base File = Available in file base Past = Previous Parts available Unit GFX; INTERFACE USES crt; CONST VGA = $A000; TYPE Virtual = Array [1..64000] of byte; { The size of our Virtual Screen } VirtPtr = ^Virtual; { Pointer to the virtual screen } VAR Virscr : VirtPtr; { Our first Virtual screen } Vaddr : word; { The segment of our virtual screen} Procedure SetMCGA; { This procedure gets you into 320x200x256 mode. } Procedure SetText; { This procedure returns you to text mode. } Procedure Cls (Where:word;Col : Byte); { This clears the screen to the specified color } Procedure SetUpVirtual; { This sets up the memory needed for the virtual screen } Procedure ShutDown; { This frees the memory used by the virtual screen } procedure flip(source,dest:Word); { This copies the entire screen at "source" to destination } Procedure Pal(Col,R,G,B : Byte); { This sets the Red, Green and Blue values of a certain color } Procedure GetPal(Col : Byte; Var R,G,B : Byte); { This gets the Red, Green and Blue values of a certain color } procedure WaitRetrace; { This waits for a vertical retrace to reduce snow on the screen } Procedure Hline (x1,x2,y:word;col:byte;where:word); { This draws a horizontal line from x1 to x2 on line y in color col } Procedure Line(a,b,c,d:integer;col:byte;where:word); { This draws a solid line from a,b to c,d in colour col } Procedure DrawPoly(x1,y1,x2,y2,x3,y3,x4,y4:integer;color:byte;where:word); { This draw a polygon with 4 points at x1,y1 , x2,y2 , x3,y3 , x4,y4 in color col } Function rad (theta : real) : real; { This calculates the degrees of an angle } Procedure Putpixel (X,Y : Integer; Col : Byte; where:word); { This puts a pixel on the screen by writing directly to memory. } Function Getpixel (X,Y : Integer; where:word) :Byte; { This gets the pixel on the screen by reading directly to memory. } IMPLEMENTATION {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure SetMCGA; { This procedure gets you into 320x200x256 mode. } BEGIN asm mov ax,0013h int 10h end; END; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure SetText; { This procedure returns you to text mode. } BEGIN asm mov ax,0003h int 10h end; END; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Cls (Where:word;Col : Byte); assembler; { This clears the screen to the specified color } asm push es mov cx, 32000; mov es,[where] xor di,di mov al,[col] mov ah,al rep stosw pop es End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure SetUpVirtual; { This sets up the memory needed for the virtual screen } BEGIN GetMem (VirScr,64000); vaddr := seg (virscr^); END; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure ShutDown; { This frees the memory used by the virtual screen } BEGIN FreeMem (VirScr,64000); END; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} procedure flip(source,dest:Word); assembler; { This copies the entire screen at "source" to destination } asm push ds mov ax, [Dest] mov es, ax mov ax, [Source] mov ds, ax xor si, si xor di, di mov cx, 32000 rep movsw pop ds end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Pal(Col,R,G,B : Byte); assembler; { This sets the Red, Green and Blue values of a certain color } asm mov dx,3c8h mov al,[col] out dx,al inc dx mov al,[r] out dx,al mov al,[g] out dx,al mov al,[b] out dx,al end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure GetPal(Col : Byte; Var R,G,B : Byte); { This gets the Red, Green and Blue values of a certain color } Var rr,gg,bb : Byte; Begin asm mov dx,3c7h mov al,col out dx,al add dx,2 in al,dx mov [rr],al in al,dx mov [gg],al in al,dx mov [bb],al end; r := rr; g := gg; b := bb; end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} procedure WaitRetrace; assembler; { This waits for a vertical retrace to reduce snow on the screen } label l1, l2; asm mov dx,3DAh l1: in al,dx and al,08h jnz l1 l2: in al,dx and al,08h jz l2 end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Hline (x1,x2,y:word;col:byte;where:word); assembler; { This draws a horizontal line from x1 to x2 on line y in color col } asm mov ax,where mov es,ax mov ax,y mov di,ax shl ax,8 shl di,6 add di,ax add di,x1 mov al,col mov ah,al mov cx,x2 sub cx,x1 shr cx,1 jnc @start stosb @Start : rep stosw end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Line(a,b,c,d:integer;col:byte;where:word); { This draws a solid line from a,b to c,d in colour col } function sgn(a:real):integer; begin if a>0 then sgn:=+1; if a<0 then sgn:=-1; if a=0 then sgn:=0; end; var i,s,d1x,d1y,d2x,d2y,u,v,m,n:integer; begin u:= c - a; v:= d - b; d1x:= SGN(u); d1y:= SGN(v); d2x:= SGN(u); d2y:= 0; m:= ABS(u); n := ABS(v); IF NOT (M>N) then BEGIN d2x := 0 ; d2y := SGN(v); m := ABS(v); n := ABS(u); END; s := m shr 1; FOR i := 0 TO m DO BEGIN putpixel(a,b,col,where); s := s + n; IF not (smxy then mxy:=y2; if y3mxy then mxy:=y3; { Choose the min y mny and max y mxy } if y4mxy then mxy:=y4; if mny<0 then mny:=0; if mxy>199 then mxy:=199; if mny>199 then exit; if mxy<0 then exit; { Verticle range checking } mul1:=x1-x4; div1:=y1-y4; mul2:=x2-x1; div2:=y2-y1; mul3:=x3-x2; div3:=y3-y2; mul4:=x4-x3; div4:=y4-y3; { Constansts needed for intersection calc } for yc:=mny to mxy do begin mnx:=320; mxx:=-1; if (y4>=yc) or (y1>=yc) then if (y4<=yc) or (y1<=yc) then { Check that yc is between y1 and y4 } if not(y4=y1) then begin x:=(yc-y4)*mul1 div div1+x4; { Point of intersection on x axis } if xmxx then mxx:=x; { Set point as start or end of horiz line } end; if (y1>=yc) or (y2>=yc) then if (y1<=yc) or (y2<=yc) then { Check that yc is between y1 and y2 } if not(y1=y2) then begin x:=(yc-y1)*mul2 div div2+x1; { Point of intersection on x axis } if xmxx then mxx:=x; { Set point as start or end of horiz line } end; if (y2>=yc) or (y3>=yc) then if (y2<=yc) or (y3<=yc) then { Check that yc is between y2 and y3 } if not(y2=y3) then begin x:=(yc-y2)*mul3 div div3+x2; { Point of intersection on x axis } if xmxx then mxx:=x; { Set point as start or end of horiz line } end; if (y3>=yc) or (y4>=yc) then if (y3<=yc) or (y4<=yc) then { Check that yc is between y3 and y4 } if not(y3=y4) then begin x:=(yc-y3)*mul4 div div4+x3; { Point of intersection on x axis } if xmxx then mxx:=x; { Set point as start or end of horiz line } end; if mnx<0 then mnx:=0; if mxx>319 then mxx:=319; { Range checking on horizontal line } if mnx<=mxx then hline (mnx,mxx,yc,color,where); { Draw the horizontal line } end; end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Function rad (theta : real) : real; { This calculates the degrees of an angle } BEGIN rad := theta * pi / 180 END; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Putpixel (X,Y : Integer; Col : Byte; where:word); assembler; { This puts a pixel on the screen by writing directly to memory. } Asm mov ax,[where] mov es,ax mov bx,[X] mov dx,[Y] mov di,bx mov bx, dx {; bx = dx} shl dx, 8 shl bx, 6 add dx, bx {; dx = dx + bx (ie y*320)} add di, dx {; finalise location} mov al, [Col] stosb End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Function Getpixel (X,Y : Integer; where:word):byte; assembler; { This puts a pixel on the screen by writing directly to memory. } Asm mov ax,[where] mov es,ax mov bx,[X] mov dx,[Y] mov di,bx mov bx, dx {; bx = dx} shl dx, 8 shl bx, 6 add dx, bx {; dx = dx + bx (ie y*320)} add di, dx {; finalise location} lodsb End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure LoadCEL (FileName : string; ScrPtr : pointer); { This loads the cel 'filename' into the pointer scrptr } var Fil : file; Buf : array [1..1024] of byte; BlocksRead, Count : word; begin assign (Fil, FileName); reset (Fil, 1); BlockRead (Fil, Buf, 800); { Read and ignore the 800 byte header } Count := 0; BlocksRead := $FFFF; while (not eof (Fil)) and (BlocksRead <> 0) do begin BlockRead (Fil, mem [seg (ScrPtr^): ofs (ScrPtr^) + Count], 1024, BlocksRead); Count := Count + 1024; end; close (Fil); end; BEGIN END.Uses Crt,GFX; Const Size : Byte = 80; { Size = 40 = 1 across, 4 down } { Size = 80 = 2 across, 2 down } { Size = 160 = 4 across, 1 down } bit : Array [1..897] of byte = ( 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,33,2,151,5,149,6,148,7,147,8,49,2,95,8,49, 4,93,9,49,3,93,4,2,3,49,4,92,4,3,3,48,4,92,4,3,4,48,4,91,4,4,3,48,4,92,4,3,4, 48,3,58,2,32,4,4,4,47,4,57,3,31,4,5,3,48,3,57,4,30,4,5,4,47,3,57,5,29,4,6,4,46, 4,57,4,29,4,7,3,47,3,58,2,30,4,7,4,46,4,90,4,7,4,46,3,90,4,8,4,27,2,16,3,90,4, 8,9,22,3,16,3,89,4,5,13,8,6,8,3,15,3,90,4,2,15,6,10,6,3,16,3,6,1,21,1,9,2,7,1, 21,6,14,18,9,5,2,4,5,4,1,4,10,3,4,5,10,2,7,3,8,2,5,3,9,3,7,8,13,13,1,4,9,4,5,3, 5,3,1,6,9,3,3,6,9,4,5,4,8,3,3,4,9,3,6,9,11,10,6,4,8,4,6,3,4,11,8,3,2,7,9,5,4,4, 9,3,2,4,9,3,6,4,4,2,8,10,9,4,7,4,6,3,5,5,3,3,8,3,1,8,8,5,4,5,8,3,3,3,9,4,5,4,5, 2,5,10,12,4,7,3,5,5,4,5,4,3,7,3,1,4,1,3,9,4,5,4,9,3,2,3,10,3,6,3,5,3,4,10,13,3, 8,3,2,7,5,4,5,3,7,7,1,3,9,4,5,5,9,3,1,3,10,3,6,3,5,4,4,5,1,4,12,4,8,3,2,5,6,4, 5,4,6,6,2,4,8,4,5,5,10,6,10,4,5,4,5,3,5,2,3,4,13,4,8,3,3,1,9,3,6,3,7,5,3,3,5,1, 3,3,5,5,4,2,5,5,11,3,6,3,5,4,10,3,14,4,8,3,12,3,6,4,6,5,3,3,5,2,2,4,4,6,4,2,5, 5,6,1,3,4,5,3,6,3,10,4,14,4,5,1,2,4,11,3,6,3,7,5,3,3,4,3,1,4,4,6,4,3,5,4,6,2,3, 3,6,3,5,4,9,4,15,3,5,2,3,4,9,3,6,4,7,4,3,3,5,2,2,3,4,7,3,3,6,3,6,3,2,4,5,4,5,3, 10,3,15,4,4,3,4,3,9,3,6,3,7,4,4,3,4,3,1,4,3,3,1,3,3,3,6,4,6,2,3,3,6,3,5,4,9,4, 15,4,4,3,4,4,7,3,6,4,7,4,3,3,4,3,2,3,3,3,2,3,2,4,5,5,5,3,2,4,6,3,5,4,8,4,16,4, 4,2,6,3,7,3,5,4,7,4,4,3,3,3,3,8,2,3,2,4,5,6,4,3,3,3,7,3,4,5,8,4,16,4,4,2,6,3,6, 3,5,4,8,3,5,8,3,9,2,3,1,4,6,6,3,3,4,3,7,3,3,6,7,4,17,4,4,3,5,3,6,3,4,4,9,3,5,8, 3,7,3,8,6,3,1,4,1,4,3,4,7,3,2,3,1,3,7,4,17,4,4,3,5,3,5,11,9,3,6,7,4,6,4,7,6,3, 2,8,4,3,8,7,2,3,6,4,18,3,5,4,3,4,5,10,10,3,6,6,6,4,4,6,7,3,4,6,5,3,8,7,2,4,4,4, 19,3,5,10,5,3,1,6,11,3,7,3,16,5,7,4,4,5,6,3,8,6,3,5,3,4,19,3,6,9,5,3,18,2,25,5, 9,3,6,3,7,2,10,3,6,4,3,3,20,3,8,5,6,3,44,6,10,2,39,3,3,2,22,2,19,3,43,7,101,3, 42,8,102,3,41,4,1,4,101,4,39,5,2,3,102,3,39,4,4,3,102,3,38,4,4,4,101,3,38,4,5, 3,102,3,37,4,5,4,101,4,36,4,6,3,102,3,37,3,6,4,102,3,36,4,6,3,102,3,37,3,6,3, 103,3,37,3,5,4,102,4,37,3,4,4,103,3,38,10,104,3,38,9,105,2,40,7,106,2,41,4,0); {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure InitChain4; ASSEMBLER; { This procedure gets you into Chain 4 mode } Asm mov ax, 13h int 10h { Get into MCGA Mode } mov dx, 3c4h { Port 3c4h = Sequencer Address Register } mov al, 4 { Index 4 = memory mode } out dx, al inc dx { Port 3c5h ... here we set the mem mode } in al, dx and al, not 08h or al, 04h out dx, al mov dx, 3ceh mov al, 5 out dx, al inc dx in al, dx and al, not 10h out dx, al dec dx mov al, 6 out dx, al inc dx in al, dx and al, not 02h out dx, al mov dx, 3c4h mov ax, (0fh shl 8) + 2 out dx, ax mov ax, 0a000h mov es, ax sub di, di mov ax, 0000h {8080h} mov cx, 32768 cld rep stosw { Clear garbage off the screen ... } mov dx, 3d4h mov al, 14h out dx, al inc dx in al, dx and al, not 40h out dx, al dec dx mov al, 17h out dx, al inc dx in al, dx or al, 40h out dx, al mov dx, 3d4h mov al, 13h out dx, al inc dx mov al, [Size] { Size * 8 = Pixels across. Only 320 are visible} out dx, al End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure C4PutPixel(X,Y : Word; Col : Byte); ASSEMBLER; { This puts a pixel on the chain 4 screen } Asm mov ax,[y] xor bx,bx mov bl,[size] imul bx shl ax,1 mov bx,ax mov ax, [X] mov cx, ax shr ax, 2 add bx, ax and cx, 00000011b mov ah, 1 shl ah, cl mov dx, 3c4h { Sequencer Register } mov al, 2 { Map Mask Index } out dx, ax mov ax, 0a000h mov es, ax mov al, [col] mov es: [bx], al End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Plane(Which : Byte); ASSEMBLER; { This sets the plane to write to in Chain 4} Asm mov al, 2h mov ah, 1 mov cl, [Which] shl ah, cl mov dx, 3c4h { Sequencer Register } out dx, ax End; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} procedure moveto(x, y : word); { This moves to position x*4,y on a chain 4 screen } var o : word; begin o := y*size*2+x; asm mov bx, [o] mov ah, bh mov al, 0ch mov dx, 3d4h out dx, ax mov ah, bl mov al, 0dh mov dx, 3d4h out dx, ax end; end; {ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ} Procedure Putpic (x,y:integer); { This put's the picture at coordinates x,y on the chain-4 screen } Var loop1,loop2:integer; depth,cur:integer; BEGIN depth:=1; cur:=0; For loop1:=1 to 897 do BEGIN for loop2:=1 to bit [loop1] do BEGIN if cur<>0 then c4putpixel ((depth mod 155)+x,(depth div 155)+y,depth div 155); inc (depth); END; cur:=(cur+1) mod 2; END; END; Procedure Play; Var loop1,loop2:integer; xpos,ypos,xdir,ydir:integer; ch:char; Begin for loop1:=1 to 62 do pal (loop1,loop1,0,62-loop1); { This sets up the pallette for the pic } MoveTo(0,0); { This moves the view to the top left hand corner } for loop1:=0 to 3 do for loop2:=0 to 5 do putpic (loop1*160,loop2*66); { This places the picture all over the chain-4 screen } readkey; ch:=#0; xpos:=random (78)+1; ypos:=random (198)+1; { Random start positions for the view } xdir:=1; ydir:=1; repeat moveto (xpos,ypos); waitretrace; { Take this out and watch the screen go crazy! } xpos:=xpos+xdir; ypos:=ypos+ydir; if (xpos>79) or (xpos<1) then xdir:=-xdir; if (ypos>199) or (ypos<1) then ydir:=-ydir; { Hit a boundry, change direction! } if keypressed then ch:=readkey; until ch=#27; { Quit when escape is pressed } End; BEGIN clrscr; writeln ('Hello there! Here is the tenth tutorial, on Chain-4! You will notice'); writeln ('that there are two pascal files here : one is a unit containing all'); writeln ('our base graphics routines, and one is the demo program.'); writeln; writeln ('In the demo program, we will do the necessary port stuff to get into'); writeln ('Chain-4. Once in Chain-4 mode, I will put down text saying ASPHYXIA'); writeln ('over the entire screen. After a key is pressed, the viewport will'); writeln ('bounce around, displaying the entire Chain-4 screen. The program will'); writeln ('end when [ESC] is pressed. The code here is really basic (except for'); writeln ('those port values), and should be very easy to understand.'); writeln; writeln; Write (' Hit any key to contine ...'); Readkey; initChain4; play; SetText; Writeln ('All done. This concludes the tenth sample program in the ASPHYXIA'); Writeln ('Training series. You may reach DENTHOR under the names of GRANT'); Writeln ('SMITH/DENTHOR/ASPHYXIA on the ASPHYXIA BBS. I am also an avid'); Writeln ('Connectix BBS user, and occasionally read RSAProg. E-mail me at :'); Writeln (' smith9@batis.bis.und.ac.za'); Writeln ('The numbers are available in the main text. You may also write to me at:'); Writeln (' Grant Smith'); Writeln (' P.O. Box 270'); Writeln (' Kloof'); Writeln (' 3640'); Writeln (' Natal'); Writeln (' South Africa'); Writeln ('I hope to hear from you soon!'); Writeln; Writeln; Write ('Hit any key to exit ...'); Readkey; END. [BACK] Back Discuss this article in the forums
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