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shipwren/PT/+P2
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Personal collection » Acorn hard disk » misc » misc3 |
| Filename: | shipwren/PT/+P2 |
| Read OK: | ✔ |
| File size: | 1043 bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
Duplicates
There are 5 duplicate copies of this file in the archive:
- Personal collection » Acorn ADFS disks » Archimedes » Unlabelled_disk_2.ADF » PT/+P2
- Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_35.ADF » P/+P2
- Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_36.ADF » F/+P2
- Personal collection » Acorn hard disk » misc » misc3 » shipwren/PT/+P2
- Personal collection » Acorn hard disk » zipped_disks » elk03 » eug35/P/+P2
- Personal collection » Acorn hard disk » zipped_disks » elk03 » eug36/F/+P2
File contents
After you have decided which mode to use, and so you know how many
colours are available, you must decide what colours these are going to
be. In MODE 2, where you have 16 colours, you have access to all of the
colours available, and so this choice does not affect you. In 4 colour
modes, on the other hand, you only initially have access to black, red,
yellow and white. These are a warm selection of colours, but you might
want a colder selection in your program, or just simply a set of colours
which go well with your screen design. To do this you use the command:
VDU 19,logical colour number,actual colour number,0,0,0
The logical colour number is the number that you use with the colour
command to select that particular colour. In a four colour mode this must
be between 0 and 3, and in a two colour mode this must be either 0 or 1.
The actual colour number is the number of the colour which you want to
assign to that logical colour. The actual colour numbers are given below:
0-Black 8-Flashing black/white
1-Red 9-Flashing red/cyan
2-Green 10-Flashing grenn/magenta
3-Yellow 11-Flashing yellow/blue
4-Blue 12-Flashing blue/yellow
5-Magenta (purple) 13-Flashing magenta/green
6-Cyan (light blue) 14-Flashing cyan/red
7-White 15-Flashing white/black
Looking at the table above, you might wonder what the difference is
between flashing black/white and flashing white/black. If you look at
them both seperately, there is little difference, but if you look at them
together, you see that when one is black the other is white, and vice
versa. So, for example, if you put a logo on the screen with the logo in
colour 8 and the background in colour 15, the screen flashes between
white on black and black on white. To demonstrate this, turn on your
Electron and type:
MODE 6:VDU 19,1,8,0,0,0:VDU 19,0,15,0,0,0
You can take this further. Four is the maximum number of colours
allowed on screen at any one time. Therefore for different screens you
can have different selections of colours. The main menu screen might be
in warm colours, and then subsequent menu screens in colder colours. The
changing of these logical colours is called "Palette Switching". You can
go even further and create simple animation using palette switching; an
effect which is called "Colour Cycling". For example, you put a row of
colour 3 above a row of colour 2, with a row of colour 1 below that, and
colour 0 at the base. Initially, you set all logical colours to black.
Then, if you set logical colour 0 to white, the base appears. Now set
logical colour 1 to white as well, the bar moves up the screen. Repeat
this with colours 2 and 3, and you have a simple animation. This is even
more powerful in MODE 2, where you can go through 16 rows up. This is
demonstrated at the end of the tutorial.
The swirly effect on the title screen of this issue's title screen
was achieved in this way. The colours black, blue, cyan and white are
cycled through a pattern on the screen in order.
Having decided which graphics mode you are going to use, and which
colours to have on the screen, you must decide how you are going to get
your graphics onto the screen. There are many methods for producing
graphics, and which you choose depends upon what you want the graphics
for, and what you want them to do (and, of course, your programming
ability). The most obvious is the PRINT command. This is a quick, easy
way of putting text onto the screen. When used with the COLOUR command
and the TAB(x,y) function, many interesting effects can be achieved.
These are, however, greatly limited by the fact that only letters can be
displayed on the screen. This limitation may be overcome using user
defined characters (see the Graphics chapter of the User Manual for
details). Even using these characters, however, there are serious
limitations. They can only use one colour per character, and so even if
you make different characters different colours, your screen will still
appear rather dull. Also, they are difficult to use when dealing with
large areas of the screen.
00000000 20 20 20 20 20 41 66 74 65 72 20 79 6f 75 20 68 | After you h| 00000010 61 76 65 20 64 65 63 69 64 65 64 20 77 68 69 63 |ave decided whic| 00000020 68 20 6d 6f 64 65 20 74 6f 20 75 73 65 2c 20 61 |h mode to use, a| 00000030 6e 64 20 73 6f 20 79 6f 75 20 6b 6e 6f 77 20 68 |nd so you know h| 00000040 6f 77 20 6d 61 6e 79 0d 63 6f 6c 6f 75 72 73 20 |ow many.colours | 00000050 61 72 65 20 61 76 61 69 6c 61 62 6c 65 2c 20 79 |are available, y| 00000060 6f 75 20 6d 75 73 74 20 64 65 63 69 64 65 20 77 |ou must decide w| 00000070 68 61 74 20 63 6f 6c 6f 75 72 73 20 74 68 65 73 |hat colours thes| 00000080 65 20 61 72 65 20 67 6f 69 6e 67 20 74 6f 0d 62 |e are going to.b| 00000090 65 2e 20 49 6e 20 4d 4f 44 45 20 32 2c 20 77 68 |e. In MODE 2, wh| 000000a0 65 72 65 20 79 6f 75 20 68 61 76 65 20 31 36 20 |ere you have 16 | 000000b0 63 6f 6c 6f 75 72 73 2c 20 79 6f 75 20 68 61 76 |colours, you hav| 000000c0 65 20 61 63 63 65 73 73 20 74 6f 20 61 6c 6c 20 |e access to all | 000000d0 6f 66 20 74 68 65 0d 63 6f 6c 6f 75 72 73 20 61 |of the.colours a| 000000e0 76 61 69 6c 61 62 6c 65 2c 20 61 6e 64 20 73 6f |vailable, and so| 000000f0 20 74 68 69 73 20 63 68 6f 69 63 65 20 64 6f 65 | this choice doe| 00000100 73 20 6e 6f 74 20 61 66 66 65 63 74 20 79 6f 75 |s not affect you| 00000110 2e 20 49 6e 20 34 20 63 6f 6c 6f 75 72 0d 6d 6f |. In 4 colour.mo| 00000120 64 65 73 2c 20 6f 6e 20 74 68 65 20 6f 74 68 65 |des, on the othe| 00000130 72 20 68 61 6e 64 2c 20 79 6f 75 20 6f 6e 6c 79 |r hand, you only| 00000140 20 69 6e 69 74 69 61 6c 6c 79 20 68 61 76 65 20 | initially have | 00000150 61 63 63 65 73 73 20 74 6f 20 62 6c 61 63 6b 2c |access to black,| 00000160 20 72 65 64 2c 0d 79 65 6c 6c 6f 77 20 61 6e 64 | red,.yellow and| 00000170 20 77 68 69 74 65 2e 20 54 68 65 73 65 20 61 72 | white. These ar| 00000180 65 20 61 20 77 61 72 6d 20 73 65 6c 65 63 74 69 |e a warm selecti| 00000190 6f 6e 20 6f 66 20 63 6f 6c 6f 75 72 73 2c 20 62 |on of colours, b| 000001a0 75 74 20 79 6f 75 20 6d 69 67 68 74 0d 77 61 6e |ut you might.wan| 000001b0 74 20 61 20 63 6f 6c 64 65 72 20 73 65 6c 65 63 |t a colder selec| 000001c0 74 69 6f 6e 20 69 6e 20 79 6f 75 72 20 70 72 6f |tion in your pro| 000001d0 67 72 61 6d 2c 20 6f 72 20 6a 75 73 74 20 73 69 |gram, or just si| 000001e0 6d 70 6c 79 20 61 20 73 65 74 20 6f 66 20 63 6f |mply a set of co| 000001f0 6c 6f 75 72 73 0d 77 68 69 63 68 20 67 6f 20 77 |lours.which go w| 00000200 65 6c 6c 20 77 69 74 68 20 79 6f 75 72 20 73 63 |ell with your sc| 00000210 72 65 65 6e 20 64 65 73 69 67 6e 2e 20 54 6f 20 |reen design. To | 00000220 64 6f 20 74 68 69 73 20 79 6f 75 20 75 73 65 20 |do this you use | 00000230 74 68 65 20 63 6f 6d 6d 61 6e 64 3a 0d 0d 56 44 |the command:..VD| 00000240 55 20 31 39 2c 6c 6f 67 69 63 61 6c 20 63 6f 6c |U 19,logical col| 00000250 6f 75 72 20 6e 75 6d 62 65 72 2c 61 63 74 75 61 |our number,actua| 00000260 6c 20 63 6f 6c 6f 75 72 20 6e 75 6d 62 65 72 2c |l colour number,| 00000270 30 2c 30 2c 30 0d 0d 20 20 20 20 20 54 68 65 20 |0,0,0.. The | 00000280 6c 6f 67 69 63 61 6c 20 63 6f 6c 6f 75 72 20 6e |logical colour n| 00000290 75 6d 62 65 72 20 69 73 20 74 68 65 20 6e 75 6d |umber is the num| 000002a0 62 65 72 20 74 68 61 74 20 79 6f 75 20 75 73 65 |ber that you use| 000002b0 20 77 69 74 68 20 74 68 65 20 63 6f 6c 6f 75 72 | with the colour| 000002c0 0d 63 6f 6d 6d 61 6e 64 20 74 6f 20 73 65 6c 65 |.command to sele| 000002d0 63 74 20 74 68 61 74 20 70 61 72 74 69 63 75 6c |ct that particul| 000002e0 61 72 20 63 6f 6c 6f 75 72 2e 20 49 6e 20 61 20 |ar colour. In a | 000002f0 66 6f 75 72 20 63 6f 6c 6f 75 72 20 6d 6f 64 65 |four colour mode| 00000300 20 74 68 69 73 20 6d 75 73 74 0d 62 65 20 62 65 | this must.be be| 00000310 74 77 65 65 6e 20 30 20 61 6e 64 20 33 2c 20 61 |tween 0 and 3, a| 00000320 6e 64 20 69 6e 20 61 20 74 77 6f 20 63 6f 6c 6f |nd in a two colo| 00000330 75 72 20 6d 6f 64 65 20 74 68 69 73 20 6d 75 73 |ur mode this mus| 00000340 74 20 62 65 20 65 69 74 68 65 72 20 30 20 6f 72 |t be either 0 or| 00000350 20 31 2e 0d 54 68 65 20 61 63 74 75 61 6c 20 63 | 1..The actual c| 00000360 6f 6c 6f 75 72 20 6e 75 6d 62 65 72 20 69 73 20 |olour number is | 00000370 74 68 65 20 6e 75 6d 62 65 72 20 6f 66 20 74 68 |the number of th| 00000380 65 20 63 6f 6c 6f 75 72 20 77 68 69 63 68 20 79 |e colour which y| 00000390 6f 75 20 77 61 6e 74 20 74 6f 0d 61 73 73 69 67 |ou want to.assig| 000003a0 6e 20 74 6f 20 74 68 61 74 20 6c 6f 67 69 63 61 |n to that logica| 000003b0 6c 20 63 6f 6c 6f 75 72 2e 20 54 68 65 20 61 63 |l colour. The ac| 000003c0 74 75 61 6c 20 63 6f 6c 6f 75 72 20 6e 75 6d 62 |tual colour numb| 000003d0 65 72 73 20 61 72 65 20 67 69 76 65 6e 20 62 65 |ers are given be| 000003e0 6c 6f 77 3a 0d 0d 30 2d 42 6c 61 63 6b 20 20 20 |low:..0-Black | 000003f0 20 20 20 20 20 20 20 20 20 20 20 20 38 2d 46 6c | 8-Fl| 00000400 61 73 68 69 6e 67 20 62 6c 61 63 6b 2f 77 68 69 |ashing black/whi| 00000410 74 65 0d 31 2d 52 65 64 20 20 20 20 20 20 20 20 |te.1-Red | 00000420 20 20 20 20 20 20 20 20 20 39 2d 46 6c 61 73 68 | 9-Flash| 00000430 69 6e 67 20 72 65 64 2f 63 79 61 6e 0d 32 2d 47 |ing red/cyan.2-G| 00000440 72 65 65 6e 20 20 20 20 20 20 20 20 20 20 20 20 |reen | 00000450 20 20 31 30 2d 46 6c 61 73 68 69 6e 67 20 67 72 | 10-Flashing gr| 00000460 65 6e 6e 2f 6d 61 67 65 6e 74 61 0d 33 2d 59 65 |enn/magenta.3-Ye| 00000470 6c 6c 6f 77 20 20 20 20 20 20 20 20 20 20 20 20 |llow | 00000480 20 31 31 2d 46 6c 61 73 68 69 6e 67 20 79 65 6c | 11-Flashing yel| 00000490 6c 6f 77 2f 62 6c 75 65 0d 34 2d 42 6c 75 65 20 |low/blue.4-Blue | 000004a0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 31 32 | 12| 000004b0 2d 46 6c 61 73 68 69 6e 67 20 62 6c 75 65 2f 79 |-Flashing blue/y| 000004c0 65 6c 6c 6f 77 0d 35 2d 4d 61 67 65 6e 74 61 20 |ellow.5-Magenta | 000004d0 28 70 75 72 70 6c 65 29 20 20 20 31 33 2d 46 6c |(purple) 13-Fl| 000004e0 61 73 68 69 6e 67 20 6d 61 67 65 6e 74 61 2f 67 |ashing magenta/g| 000004f0 72 65 65 6e 0d 36 2d 43 79 61 6e 20 28 6c 69 67 |reen.6-Cyan (lig| 00000500 68 74 20 62 6c 75 65 29 20 20 31 34 2d 46 6c 61 |ht blue) 14-Fla| 00000510 73 68 69 6e 67 20 63 79 61 6e 2f 72 65 64 0d 37 |shing cyan/red.7| 00000520 2d 57 68 69 74 65 20 20 20 20 20 20 20 20 20 20 |-White | 00000530 20 20 20 20 31 35 2d 46 6c 61 73 68 69 6e 67 20 | 15-Flashing | 00000540 77 68 69 74 65 2f 62 6c 61 63 6b 0d 0d 20 20 20 |white/black.. | 00000550 20 20 4c 6f 6f 6b 69 6e 67 20 61 74 20 74 68 65 | Looking at the| 00000560 20 74 61 62 6c 65 20 61 62 6f 76 65 2c 20 79 6f | table above, yo| 00000570 75 20 6d 69 67 68 74 20 77 6f 6e 64 65 72 20 77 |u might wonder w| 00000580 68 61 74 20 74 68 65 20 64 69 66 66 65 72 65 6e |hat the differen| 00000590 63 65 20 69 73 0d 62 65 74 77 65 65 6e 20 66 6c |ce is.between fl| 000005a0 61 73 68 69 6e 67 20 62 6c 61 63 6b 2f 77 68 69 |ashing black/whi| 000005b0 74 65 20 61 6e 64 20 66 6c 61 73 68 69 6e 67 20 |te and flashing | 000005c0 77 68 69 74 65 2f 62 6c 61 63 6b 2e 20 49 66 20 |white/black. If | 000005d0 79 6f 75 20 6c 6f 6f 6b 20 61 74 0d 74 68 65 6d |you look at.them| 000005e0 20 62 6f 74 68 20 73 65 70 65 72 61 74 65 6c 79 | both seperately| 000005f0 2c 20 74 68 65 72 65 20 69 73 20 6c 69 74 74 6c |, there is littl| 00000600 65 20 64 69 66 66 65 72 65 6e 63 65 2c 20 62 75 |e difference, bu| 00000610 74 20 69 66 20 79 6f 75 20 6c 6f 6f 6b 20 61 74 |t if you look at| 00000620 20 74 68 65 6d 0d 74 6f 67 65 74 68 65 72 2c 20 | them.together, | 00000630 79 6f 75 20 73 65 65 20 74 68 61 74 20 77 68 65 |you see that whe| 00000640 6e 20 6f 6e 65 20 69 73 20 62 6c 61 63 6b 20 74 |n one is black t| 00000650 68 65 20 6f 74 68 65 72 20 69 73 20 77 68 69 74 |he other is whit| 00000660 65 2c 20 61 6e 64 20 76 69 63 65 0d 76 65 72 73 |e, and vice.vers| 00000670 61 2e 20 53 6f 2c 20 66 6f 72 20 65 78 61 6d 70 |a. So, for examp| 00000680 6c 65 2c 20 69 66 20 79 6f 75 20 70 75 74 20 61 |le, if you put a| 00000690 20 6c 6f 67 6f 20 6f 6e 20 74 68 65 20 73 63 72 | logo on the scr| 000006a0 65 65 6e 20 77 69 74 68 20 74 68 65 20 6c 6f 67 |een with the log| 000006b0 6f 20 69 6e 0d 63 6f 6c 6f 75 72 20 38 20 61 6e |o in.colour 8 an| 000006c0 64 20 74 68 65 20 62 61 63 6b 67 72 6f 75 6e 64 |d the background| 000006d0 20 69 6e 20 63 6f 6c 6f 75 72 20 31 35 2c 20 74 | in colour 15, t| 000006e0 68 65 20 73 63 72 65 65 6e 20 66 6c 61 73 68 65 |he screen flashe| 000006f0 73 20 62 65 74 77 65 65 6e 0d 77 68 69 74 65 20 |s between.white | 00000700 6f 6e 20 62 6c 61 63 6b 20 61 6e 64 20 62 6c 61 |on black and bla| 00000710 63 6b 20 6f 6e 20 77 68 69 74 65 2e 20 54 6f 20 |ck on white. To | 00000720 64 65 6d 6f 6e 73 74 72 61 74 65 20 74 68 69 73 |demonstrate this| 00000730 2c 20 74 75 72 6e 20 6f 6e 20 79 6f 75 72 0d 45 |, turn on your.E| 00000740 6c 65 63 74 72 6f 6e 20 61 6e 64 20 74 79 70 65 |lectron and type| 00000750 3a 0d 0d 4d 4f 44 45 20 36 3a 56 44 55 20 31 39 |:..MODE 6:VDU 19| 00000760 2c 31 2c 38 2c 30 2c 30 2c 30 3a 56 44 55 20 31 |,1,8,0,0,0:VDU 1| 00000770 39 2c 30 2c 31 35 2c 30 2c 30 2c 30 0d 0d 20 20 |9,0,15,0,0,0.. | 00000780 20 20 20 59 6f 75 20 63 61 6e 20 74 61 6b 65 20 | You can take | 00000790 74 68 69 73 20 66 75 72 74 68 65 72 2e 20 46 6f |this further. Fo| 000007a0 75 72 20 69 73 20 74 68 65 20 6d 61 78 69 6d 75 |ur is the maximu| 000007b0 6d 20 6e 75 6d 62 65 72 20 6f 66 20 63 6f 6c 6f |m number of colo| 000007c0 75 72 73 20 0d 61 6c 6c 6f 77 65 64 20 6f 6e 20 |urs .allowed on | 000007d0 73 63 72 65 65 6e 20 61 74 20 61 6e 79 20 6f 6e |screen at any on| 000007e0 65 20 74 69 6d 65 2e 20 54 68 65 72 65 66 6f 72 |e time. Therefor| 000007f0 65 20 66 6f 72 20 64 69 66 66 65 72 65 6e 74 20 |e for different | 00000800 73 63 72 65 65 6e 73 20 79 6f 75 0d 63 61 6e 20 |screens you.can | 00000810 68 61 76 65 20 64 69 66 66 65 72 65 6e 74 20 73 |have different s| 00000820 65 6c 65 63 74 69 6f 6e 73 20 6f 66 20 63 6f 6c |elections of col| 00000830 6f 75 72 73 2e 20 54 68 65 20 6d 61 69 6e 20 6d |ours. The main m| 00000840 65 6e 75 20 73 63 72 65 65 6e 20 6d 69 67 68 74 |enu screen might| 00000850 20 62 65 0d 69 6e 20 77 61 72 6d 20 63 6f 6c 6f | be.in warm colo| 00000860 75 72 73 2c 20 61 6e 64 20 74 68 65 6e 20 73 75 |urs, and then su| 00000870 62 73 65 71 75 65 6e 74 20 6d 65 6e 75 20 73 63 |bsequent menu sc| 00000880 72 65 65 6e 73 20 69 6e 20 63 6f 6c 64 65 72 20 |reens in colder | 00000890 63 6f 6c 6f 75 72 73 2e 20 54 68 65 0d 63 68 61 |colours. The.cha| 000008a0 6e 67 69 6e 67 20 6f 66 20 74 68 65 73 65 20 6c |nging of these l| 000008b0 6f 67 69 63 61 6c 20 63 6f 6c 6f 75 72 73 20 69 |ogical colours i| 000008c0 73 20 63 61 6c 6c 65 64 20 22 50 61 6c 65 74 74 |s called "Palett| 000008d0 65 20 53 77 69 74 63 68 69 6e 67 22 2e 20 59 6f |e Switching". Yo| 000008e0 75 20 63 61 6e 0d 67 6f 20 65 76 65 6e 20 66 75 |u can.go even fu| 000008f0 72 74 68 65 72 20 61 6e 64 20 63 72 65 61 74 65 |rther and create| 00000900 20 73 69 6d 70 6c 65 20 61 6e 69 6d 61 74 69 6f | simple animatio| 00000910 6e 20 75 73 69 6e 67 20 70 61 6c 65 74 74 65 20 |n using palette | 00000920 73 77 69 74 63 68 69 6e 67 3b 20 61 6e 0d 65 66 |switching; an.ef| 00000930 66 65 63 74 20 77 68 69 63 68 20 69 73 20 63 61 |fect which is ca| 00000940 6c 6c 65 64 20 22 43 6f 6c 6f 75 72 20 43 79 63 |lled "Colour Cyc| 00000950 6c 69 6e 67 22 2e 20 46 6f 72 20 65 78 61 6d 70 |ling". For examp| 00000960 6c 65 2c 20 79 6f 75 20 70 75 74 20 61 20 72 6f |le, you put a ro| 00000970 77 20 6f 66 0d 63 6f 6c 6f 75 72 20 33 20 61 62 |w of.colour 3 ab| 00000980 6f 76 65 20 61 20 72 6f 77 20 6f 66 20 63 6f 6c |ove a row of col| 00000990 6f 75 72 20 32 2c 20 77 69 74 68 20 61 20 72 6f |our 2, with a ro| 000009a0 77 20 6f 66 20 63 6f 6c 6f 75 72 20 31 20 62 65 |w of colour 1 be| 000009b0 6c 6f 77 20 74 68 61 74 2c 20 61 6e 64 0d 63 6f |low that, and.co| 000009c0 6c 6f 75 72 20 30 20 61 74 20 74 68 65 20 62 61 |lour 0 at the ba| 000009d0 73 65 2e 20 49 6e 69 74 69 61 6c 6c 79 2c 20 79 |se. Initially, y| 000009e0 6f 75 20 73 65 74 20 61 6c 6c 20 6c 6f 67 69 63 |ou set all logic| 000009f0 61 6c 20 63 6f 6c 6f 75 72 73 20 74 6f 20 62 6c |al colours to bl| 00000a00 61 63 6b 2e 0d 54 68 65 6e 2c 20 69 66 20 79 6f |ack..Then, if yo| 00000a10 75 20 73 65 74 20 6c 6f 67 69 63 61 6c 20 63 6f |u set logical co| 00000a20 6c 6f 75 72 20 30 20 74 6f 20 77 68 69 74 65 2c |lour 0 to white,| 00000a30 20 74 68 65 20 62 61 73 65 20 61 70 70 65 61 72 | the base appear| 00000a40 73 2e 20 4e 6f 77 20 73 65 74 0d 6c 6f 67 69 63 |s. Now set.logic| 00000a50 61 6c 20 63 6f 6c 6f 75 72 20 31 20 74 6f 20 77 |al colour 1 to w| 00000a60 68 69 74 65 20 61 73 20 77 65 6c 6c 2c 20 74 68 |hite as well, th| 00000a70 65 20 62 61 72 20 6d 6f 76 65 73 20 75 70 20 74 |e bar moves up t| 00000a80 68 65 20 73 63 72 65 65 6e 2e 20 52 65 70 65 61 |he screen. Repea| 00000a90 74 20 0d 74 68 69 73 20 77 69 74 68 20 63 6f 6c |t .this with col| 00000aa0 6f 75 72 73 20 32 20 61 6e 64 20 33 2c 20 61 6e |ours 2 and 3, an| 00000ab0 64 20 79 6f 75 20 68 61 76 65 20 61 20 73 69 6d |d you have a sim| 00000ac0 70 6c 65 20 61 6e 69 6d 61 74 69 6f 6e 2e 20 54 |ple animation. T| 00000ad0 68 69 73 20 69 73 20 65 76 65 6e 0d 6d 6f 72 65 |his is even.more| 00000ae0 20 70 6f 77 65 72 66 75 6c 20 69 6e 20 4d 4f 44 | powerful in MOD| 00000af0 45 20 32 2c 20 77 68 65 72 65 20 79 6f 75 20 63 |E 2, where you c| 00000b00 61 6e 20 67 6f 20 74 68 72 6f 75 67 68 20 31 36 |an go through 16| 00000b10 20 72 6f 77 73 20 75 70 2e 20 54 68 69 73 20 69 | rows up. This i| 00000b20 73 0d 64 65 6d 6f 6e 73 74 72 61 74 65 64 20 61 |s.demonstrated a| 00000b30 74 20 74 68 65 20 65 6e 64 20 6f 66 20 74 68 65 |t the end of the| 00000b40 20 74 75 74 6f 72 69 61 6c 2e 0d 20 20 20 20 20 | tutorial.. | 00000b50 54 68 65 20 73 77 69 72 6c 79 20 65 66 66 65 63 |The swirly effec| 00000b60 74 20 6f 6e 20 74 68 65 20 74 69 74 6c 65 20 73 |t on the title s| 00000b70 63 72 65 65 6e 20 6f 66 20 74 68 69 73 20 69 73 |creen of this is| 00000b80 73 75 65 27 73 20 74 69 74 6c 65 20 73 63 72 65 |sue's title scre| 00000b90 65 6e 0d 77 61 73 20 61 63 68 69 65 76 65 64 20 |en.was achieved | 00000ba0 69 6e 20 74 68 69 73 20 77 61 79 2e 20 54 68 65 |in this way. The| 00000bb0 20 63 6f 6c 6f 75 72 73 20 62 6c 61 63 6b 2c 20 | colours black, | 00000bc0 62 6c 75 65 2c 20 63 79 61 6e 20 61 6e 64 20 77 |blue, cyan and w| 00000bd0 68 69 74 65 20 61 72 65 0d 63 79 63 6c 65 64 20 |hite are.cycled | 00000be0 74 68 72 6f 75 67 68 20 61 20 70 61 74 74 65 72 |through a patter| 00000bf0 6e 20 6f 6e 20 74 68 65 20 73 63 72 65 65 6e 20 |n on the screen | 00000c00 69 6e 20 6f 72 64 65 72 2e 0d 20 20 20 20 20 48 |in order.. H| 00000c10 61 76 69 6e 67 20 64 65 63 69 64 65 64 20 77 68 |aving decided wh| 00000c20 69 63 68 20 67 72 61 70 68 69 63 73 20 6d 6f 64 |ich graphics mod| 00000c30 65 20 79 6f 75 20 61 72 65 20 67 6f 69 6e 67 20 |e you are going | 00000c40 74 6f 20 75 73 65 2c 20 61 6e 64 20 77 68 69 63 |to use, and whic| 00000c50 68 0d 63 6f 6c 6f 75 72 73 20 74 6f 20 68 61 76 |h.colours to hav| 00000c60 65 20 6f 6e 20 74 68 65 20 73 63 72 65 65 6e 2c |e on the screen,| 00000c70 20 79 6f 75 20 6d 75 73 74 20 64 65 63 69 64 65 | you must decide| 00000c80 20 68 6f 77 20 79 6f 75 20 61 72 65 20 67 6f 69 | how you are goi| 00000c90 6e 67 20 74 6f 20 67 65 74 0d 79 6f 75 72 20 67 |ng to get.your g| 00000ca0 72 61 70 68 69 63 73 20 6f 6e 74 6f 20 74 68 65 |raphics onto the| 00000cb0 20 73 63 72 65 65 6e 2e 20 54 68 65 72 65 20 61 | screen. There a| 00000cc0 72 65 20 6d 61 6e 79 20 6d 65 74 68 6f 64 73 20 |re many methods | 00000cd0 66 6f 72 20 70 72 6f 64 75 63 69 6e 67 0d 67 72 |for producing.gr| 00000ce0 61 70 68 69 63 73 2c 20 61 6e 64 20 77 68 69 63 |aphics, and whic| 00000cf0 68 20 79 6f 75 20 63 68 6f 6f 73 65 20 64 65 70 |h you choose dep| 00000d00 65 6e 64 73 20 75 70 6f 6e 20 77 68 61 74 20 79 |ends upon what y| 00000d10 6f 75 20 77 61 6e 74 20 74 68 65 20 67 72 61 70 |ou want the grap| 00000d20 68 69 63 73 0d 66 6f 72 2c 20 61 6e 64 20 77 68 |hics.for, and wh| 00000d30 61 74 20 79 6f 75 20 77 61 6e 74 20 74 68 65 6d |at you want them| 00000d40 20 74 6f 20 64 6f 20 28 61 6e 64 2c 20 6f 66 20 | to do (and, of | 00000d50 63 6f 75 72 73 65 2c 20 79 6f 75 72 20 70 72 6f |course, your pro| 00000d60 67 72 61 6d 6d 69 6e 67 0d 61 62 69 6c 69 74 79 |gramming.ability| 00000d70 29 2e 20 54 68 65 20 6d 6f 73 74 20 6f 62 76 69 |). The most obvi| 00000d80 6f 75 73 20 69 73 20 74 68 65 20 50 52 49 4e 54 |ous is the PRINT| 00000d90 20 63 6f 6d 6d 61 6e 64 2e 20 54 68 69 73 20 69 | command. This i| 00000da0 73 20 61 20 71 75 69 63 6b 2c 20 65 61 73 79 0d |s a quick, easy.| 00000db0 77 61 79 20 6f 66 20 70 75 74 74 69 6e 67 20 74 |way of putting t| 00000dc0 65 78 74 20 6f 6e 74 6f 20 74 68 65 20 73 63 72 |ext onto the scr| 00000dd0 65 65 6e 2e 20 57 68 65 6e 20 75 73 65 64 20 77 |een. When used w| 00000de0 69 74 68 20 74 68 65 20 43 4f 4c 4f 55 52 20 63 |ith the COLOUR c| 00000df0 6f 6d 6d 61 6e 64 20 0d 61 6e 64 20 74 68 65 20 |ommand .and the | 00000e00 54 41 42 28 78 2c 79 29 20 66 75 6e 63 74 69 6f |TAB(x,y) functio| 00000e10 6e 2c 20 6d 61 6e 79 20 69 6e 74 65 72 65 73 74 |n, many interest| 00000e20 69 6e 67 20 65 66 66 65 63 74 73 20 63 61 6e 20 |ing effects can | 00000e30 62 65 20 61 63 68 69 65 76 65 64 2e 20 0d 54 68 |be achieved. .Th| 00000e40 65 73 65 20 61 72 65 2c 20 68 6f 77 65 76 65 72 |ese are, however| 00000e50 2c 20 67 72 65 61 74 6c 79 20 6c 69 6d 69 74 65 |, greatly limite| 00000e60 64 20 62 79 20 74 68 65 20 66 61 63 74 20 74 68 |d by the fact th| 00000e70 61 74 20 6f 6e 6c 79 20 6c 65 74 74 65 72 73 20 |at only letters | 00000e80 63 61 6e 20 62 65 0d 64 69 73 70 6c 61 79 65 64 |can be.displayed| 00000e90 20 6f 6e 20 74 68 65 20 73 63 72 65 65 6e 2e 20 | on the screen. | 00000ea0 54 68 69 73 20 6c 69 6d 69 74 61 74 69 6f 6e 20 |This limitation | 00000eb0 6d 61 79 20 62 65 20 6f 76 65 72 63 6f 6d 65 20 |may be overcome | 00000ec0 75 73 69 6e 67 20 75 73 65 72 0d 64 65 66 69 6e |using user.defin| 00000ed0 65 64 20 63 68 61 72 61 63 74 65 72 73 20 28 73 |ed characters (s| 00000ee0 65 65 20 74 68 65 20 47 72 61 70 68 69 63 73 20 |ee the Graphics | 00000ef0 63 68 61 70 74 65 72 20 6f 66 20 74 68 65 20 55 |chapter of the U| 00000f00 73 65 72 20 4d 61 6e 75 61 6c 20 66 6f 72 0d 64 |ser Manual for.d| 00000f10 65 74 61 69 6c 73 29 2e 20 45 76 65 6e 20 75 73 |etails). Even us| 00000f20 69 6e 67 20 74 68 65 73 65 20 63 68 61 72 61 63 |ing these charac| 00000f30 74 65 72 73 2c 20 68 6f 77 65 76 65 72 2c 20 74 |ters, however, t| 00000f40 68 65 72 65 20 61 72 65 20 73 65 72 69 6f 75 73 |here are serious| 00000f50 20 0d 6c 69 6d 69 74 61 74 69 6f 6e 73 2e 20 54 | .limitations. T| 00000f60 68 65 79 20 63 61 6e 20 6f 6e 6c 79 20 75 73 65 |hey can only use| 00000f70 20 6f 6e 65 20 63 6f 6c 6f 75 72 20 70 65 72 20 | one colour per | 00000f80 63 68 61 72 61 63 74 65 72 2c 20 61 6e 64 20 73 |character, and s| 00000f90 6f 20 65 76 65 6e 20 69 66 0d 79 6f 75 20 6d 61 |o even if.you ma| 00000fa0 6b 65 20 64 69 66 66 65 72 65 6e 74 20 63 68 61 |ke different cha| 00000fb0 72 61 63 74 65 72 73 20 64 69 66 66 65 72 65 6e |racters differen| 00000fc0 74 20 63 6f 6c 6f 75 72 73 2c 20 79 6f 75 72 20 |t colours, your | 00000fd0 73 63 72 65 65 6e 20 77 69 6c 6c 20 73 74 69 6c |screen will stil| 00000fe0 6c 0d 61 70 70 65 61 72 20 72 61 74 68 65 72 20 |l.appear rather | 00000ff0 64 75 6c 6c 2e 20 41 6c 73 6f 2c 20 74 68 65 79 |dull. Also, they| 00001000 20 61 72 65 20 64 69 66 66 69 63 75 6c 74 20 74 | are difficult t| 00001010 6f 20 75 73 65 20 77 68 65 6e 20 64 65 61 6c 69 |o use when deali| 00001020 6e 67 20 77 69 74 68 0d 6c 61 72 67 65 20 61 72 |ng with.large ar| 00001030 65 61 73 20 6f 66 20 74 68 65 20 73 63 72 65 65 |eas of the scree| 00001040 6e 2e 0d |n..| 00001043
.