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F/+HINT9
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 ADFS disks » Electron_User_Group » EUG_30.ADF |
| Filename: | F/+HINT9 |
| Read OK: | ✔ |
| File size: | 0720 bytes |
| Load address: | 2B204556 |
| Exec address: | 544E4948 |
File contents
Electron Television Display
When using a television set with an Acorn Electron computer you may find
that the top lines of the screen image are not displayed. The commands
shown below can be used as a "one off" or incorporated into a procedure
and called up when a complete picture is displayed on the screen. This
problem can then be easily overcome.
Using VDU 11 (CTRL K) will move the screen down one line if the text
cursor is positioned somewhere on the top line of the screen. If the
cursor is not already positioned there, this can be achieved by using the
command VDU 30 (CTRL . immediately prior to the VDU 11 command. this has
the effect of homing the text cursor to the top left hand corner of the
screen, therefore ensuring that the VDU 11 command has the desired effect.
Having carried out this operation the text cursor is now left at the top
of the screen and all text will be printed at that position. This problem
can be overcome by using the following statement instead:
A=POS : B=VPOS-1 : VDU 30,11 : P.TAB (A,B)
The variables POS and VPOS contain the X,Y co-ordinates of the text
cursor's present screen position. Having "remembered" your current screen
position you can then use the VDU 30,11 command to move the screen display
down one line. Having moved the image down the screen it is then
possible, with the P.TAB (A,B) command, to return to your original
position. You do in fact return to the same point on the X axis but one
line up on the Y axis "B=VPOS-1". this enables you to return "physically"
to the same point you left, rather than the point in the text. This is
only really necessary if your original position was on the bottom line of
the screen, as returning to that position in the text would require moving
to a position off the bottom of the screen.
00000000 0d 45 6c 65 63 74 72 6f 6e 20 54 65 6c 65 76 69 |.Electron Televi| 00000010 73 69 6f 6e 20 44 69 73 70 6c 61 79 0d 0d 57 68 |sion Display..Wh| 00000020 65 6e 20 75 73 69 6e 67 20 61 20 74 65 6c 65 76 |en using a telev| 00000030 69 73 69 6f 6e 20 73 65 74 20 77 69 74 68 20 61 |ision set with a| 00000040 6e 20 41 63 6f 72 6e 20 45 6c 65 63 74 72 6f 6e |n Acorn Electron| 00000050 20 63 6f 6d 70 75 74 65 72 20 79 6f 75 20 6d 61 | computer you ma| 00000060 79 20 66 69 6e 64 0d 74 68 61 74 20 74 68 65 20 |y find.that the | 00000070 74 6f 70 20 6c 69 6e 65 73 20 6f 66 20 74 68 65 |top lines of the| 00000080 20 73 63 72 65 65 6e 20 69 6d 61 67 65 20 61 72 | screen image ar| 00000090 65 20 6e 6f 74 20 64 69 73 70 6c 61 79 65 64 2e |e not displayed.| 000000a0 20 20 54 68 65 20 63 6f 6d 6d 61 6e 64 73 0d 73 | The commands.s| 000000b0 68 6f 77 6e 20 62 65 6c 6f 77 20 63 61 6e 20 62 |hown below can b| 000000c0 65 20 75 73 65 64 20 61 73 20 61 20 22 6f 6e 65 |e used as a "one| 000000d0 20 6f 66 66 22 20 6f 72 20 69 6e 63 6f 72 70 6f | off" or incorpo| 000000e0 72 61 74 65 64 20 69 6e 74 6f 20 61 20 70 72 6f |rated into a pro| 000000f0 63 65 64 75 72 65 0d 61 6e 64 20 63 61 6c 6c 65 |cedure.and calle| 00000100 64 20 75 70 20 77 68 65 6e 20 61 20 63 6f 6d 70 |d up when a comp| 00000110 6c 65 74 65 20 70 69 63 74 75 72 65 20 69 73 20 |lete picture is | 00000120 64 69 73 70 6c 61 79 65 64 20 6f 6e 20 74 68 65 |displayed on the| 00000130 20 73 63 72 65 65 6e 2e 20 20 54 68 69 73 0d 70 | screen. This.p| 00000140 72 6f 62 6c 65 6d 20 63 61 6e 20 74 68 65 6e 20 |roblem can then | 00000150 62 65 20 65 61 73 69 6c 79 20 6f 76 65 72 63 6f |be easily overco| 00000160 6d 65 2e 0d 0d 55 73 69 6e 67 20 56 44 55 20 31 |me...Using VDU 1| 00000170 31 20 28 43 54 52 4c 20 4b 29 20 77 69 6c 6c 20 |1 (CTRL K) will | 00000180 6d 6f 76 65 20 74 68 65 20 73 63 72 65 65 6e 20 |move the screen | 00000190 64 6f 77 6e 20 6f 6e 65 20 6c 69 6e 65 20 69 66 |down one line if| 000001a0 20 74 68 65 20 74 65 78 74 0d 63 75 72 73 6f 72 | the text.cursor| 000001b0 20 69 73 20 70 6f 73 69 74 69 6f 6e 65 64 20 73 | is positioned s| 000001c0 6f 6d 65 77 68 65 72 65 20 6f 6e 20 74 68 65 20 |omewhere on the | 000001d0 74 6f 70 20 6c 69 6e 65 20 6f 66 20 74 68 65 20 |top line of the | 000001e0 73 63 72 65 65 6e 2e 20 20 49 66 20 74 68 65 0d |screen. If the.| 000001f0 63 75 72 73 6f 72 20 69 73 20 6e 6f 74 20 61 6c |cursor is not al| 00000200 72 65 61 64 79 20 70 6f 73 69 74 69 6f 6e 65 64 |ready positioned| 00000210 20 74 68 65 72 65 2c 20 74 68 69 73 20 63 61 6e | there, this can| 00000220 20 62 65 20 61 63 68 69 65 76 65 64 20 62 79 20 | be achieved by | 00000230 75 73 69 6e 67 20 74 68 65 0d 63 6f 6d 6d 61 6e |using the.comman| 00000240 64 20 56 44 55 20 33 30 20 28 43 54 52 4c 20 2e |d VDU 30 (CTRL .| 00000250 20 69 6d 6d 65 64 69 61 74 65 6c 79 20 70 72 69 | immediately pri| 00000260 6f 72 20 74 6f 20 74 68 65 20 56 44 55 20 31 31 |or to the VDU 11| 00000270 20 63 6f 6d 6d 61 6e 64 2e 20 20 74 68 69 73 20 | command. this | 00000280 68 61 73 0d 74 68 65 20 65 66 66 65 63 74 20 6f |has.the effect o| 00000290 66 20 68 6f 6d 69 6e 67 20 74 68 65 20 74 65 78 |f homing the tex| 000002a0 74 20 63 75 72 73 6f 72 20 74 6f 20 74 68 65 20 |t cursor to the | 000002b0 74 6f 70 20 6c 65 66 74 20 68 61 6e 64 20 63 6f |top left hand co| 000002c0 72 6e 65 72 20 6f 66 20 74 68 65 0d 73 63 72 65 |rner of the.scre| 000002d0 65 6e 2c 20 74 68 65 72 65 66 6f 72 65 20 65 6e |en, therefore en| 000002e0 73 75 72 69 6e 67 20 74 68 61 74 20 74 68 65 20 |suring that the | 000002f0 56 44 55 20 31 31 20 63 6f 6d 6d 61 6e 64 20 68 |VDU 11 command h| 00000300 61 73 20 74 68 65 20 64 65 73 69 72 65 64 20 65 |as the desired e| 00000310 66 66 65 63 74 2e 0d 0d 48 61 76 69 6e 67 20 63 |ffect...Having c| 00000320 61 72 72 69 65 64 20 6f 75 74 20 74 68 69 73 20 |arried out this | 00000330 6f 70 65 72 61 74 69 6f 6e 20 74 68 65 20 74 65 |operation the te| 00000340 78 74 20 63 75 72 73 6f 72 20 69 73 20 6e 6f 77 |xt cursor is now| 00000350 20 6c 65 66 74 20 61 74 20 74 68 65 20 74 6f 70 | left at the top| 00000360 0d 6f 66 20 74 68 65 20 73 63 72 65 65 6e 20 61 |.of the screen a| 00000370 6e 64 20 61 6c 6c 20 74 65 78 74 20 77 69 6c 6c |nd all text will| 00000380 20 62 65 20 70 72 69 6e 74 65 64 20 61 74 20 74 | be printed at t| 00000390 68 61 74 20 70 6f 73 69 74 69 6f 6e 2e 20 20 54 |hat position. T| 000003a0 68 69 73 20 70 72 6f 62 6c 65 6d 0d 63 61 6e 20 |his problem.can | 000003b0 62 65 20 6f 76 65 72 63 6f 6d 65 20 62 79 20 75 |be overcome by u| 000003c0 73 69 6e 67 20 74 68 65 20 66 6f 6c 6c 6f 77 69 |sing the followi| 000003d0 6e 67 20 73 74 61 74 65 6d 65 6e 74 20 69 6e 73 |ng statement ins| 000003e0 74 65 61 64 3a 0d 0d 20 20 20 20 20 20 20 20 41 |tead:.. A| 000003f0 3d 50 4f 53 20 3a 20 42 3d 56 50 4f 53 2d 31 20 |=POS : B=VPOS-1 | 00000400 3a 20 56 44 55 20 33 30 2c 31 31 20 3a 20 50 2e |: VDU 30,11 : P.| 00000410 54 41 42 20 28 41 2c 42 29 0d 0d 54 68 65 20 76 |TAB (A,B)..The v| 00000420 61 72 69 61 62 6c 65 73 20 50 4f 53 20 61 6e 64 |ariables POS and| 00000430 20 56 50 4f 53 20 63 6f 6e 74 61 69 6e 20 74 68 | VPOS contain th| 00000440 65 20 58 2c 59 20 63 6f 2d 6f 72 64 69 6e 61 74 |e X,Y co-ordinat| 00000450 65 73 20 6f 66 20 74 68 65 20 74 65 78 74 0d 63 |es of the text.c| 00000460 75 72 73 6f 72 27 73 20 70 72 65 73 65 6e 74 20 |ursor's present | 00000470 73 63 72 65 65 6e 20 70 6f 73 69 74 69 6f 6e 2e |screen position.| 00000480 20 20 48 61 76 69 6e 67 20 22 72 65 6d 65 6d 62 | Having "rememb| 00000490 65 72 65 64 22 20 79 6f 75 72 20 63 75 72 72 65 |ered" your curre| 000004a0 6e 74 20 73 63 72 65 65 6e 0d 70 6f 73 69 74 69 |nt screen.positi| 000004b0 6f 6e 20 79 6f 75 20 63 61 6e 20 74 68 65 6e 20 |on you can then | 000004c0 75 73 65 20 74 68 65 20 56 44 55 20 33 30 2c 31 |use the VDU 30,1| 000004d0 31 20 63 6f 6d 6d 61 6e 64 20 74 6f 20 6d 6f 76 |1 command to mov| 000004e0 65 20 74 68 65 20 73 63 72 65 65 6e 20 64 69 73 |e the screen dis| 000004f0 70 6c 61 79 0d 64 6f 77 6e 20 6f 6e 65 20 6c 69 |play.down one li| 00000500 6e 65 2e 20 20 48 61 76 69 6e 67 20 6d 6f 76 65 |ne. Having move| 00000510 64 20 74 68 65 20 69 6d 61 67 65 20 64 6f 77 6e |d the image down| 00000520 20 74 68 65 20 73 63 72 65 65 6e 20 69 74 20 69 | the screen it i| 00000530 73 20 74 68 65 6e 0d 70 6f 73 73 69 62 6c 65 2c |s then.possible,| 00000540 20 77 69 74 68 20 74 68 65 20 50 2e 54 41 42 20 | with the P.TAB | 00000550 28 41 2c 42 29 20 63 6f 6d 6d 61 6e 64 2c 20 74 |(A,B) command, t| 00000560 6f 20 72 65 74 75 72 6e 20 74 6f 20 79 6f 75 72 |o return to your| 00000570 20 6f 72 69 67 69 6e 61 6c 0d 70 6f 73 69 74 69 | original.positi| 00000580 6f 6e 2e 20 20 59 6f 75 20 64 6f 20 69 6e 20 66 |on. You do in f| 00000590 61 63 74 20 72 65 74 75 72 6e 20 74 6f 20 74 68 |act return to th| 000005a0 65 20 73 61 6d 65 20 70 6f 69 6e 74 20 6f 6e 20 |e same point on | 000005b0 74 68 65 20 58 20 61 78 69 73 20 62 75 74 20 6f |the X axis but o| 000005c0 6e 65 0d 6c 69 6e 65 20 75 70 20 6f 6e 20 74 68 |ne.line up on th| 000005d0 65 20 59 20 61 78 69 73 20 22 42 3d 56 50 4f 53 |e Y axis "B=VPOS| 000005e0 2d 31 22 2e 20 20 74 68 69 73 20 65 6e 61 62 6c |-1". this enabl| 000005f0 65 73 20 79 6f 75 20 74 6f 20 72 65 74 75 72 6e |es you to return| 00000600 20 22 70 68 79 73 69 63 61 6c 6c 79 22 0d 74 6f | "physically".to| 00000610 20 74 68 65 20 73 61 6d 65 20 70 6f 69 6e 74 20 | the same point | 00000620 79 6f 75 20 6c 65 66 74 2c 20 72 61 74 68 65 72 |you left, rather| 00000630 20 74 68 61 6e 20 74 68 65 20 70 6f 69 6e 74 20 | than the point | 00000640 69 6e 20 74 68 65 20 74 65 78 74 2e 20 20 54 68 |in the text. Th| 00000650 69 73 20 69 73 0d 6f 6e 6c 79 20 72 65 61 6c 6c |is is.only reall| 00000660 79 20 6e 65 63 65 73 73 61 72 79 20 69 66 20 79 |y necessary if y| 00000670 6f 75 72 20 6f 72 69 67 69 6e 61 6c 20 70 6f 73 |our original pos| 00000680 69 74 69 6f 6e 20 77 61 73 20 6f 6e 20 74 68 65 |ition was on the| 00000690 20 62 6f 74 74 6f 6d 20 6c 69 6e 65 20 6f 66 0d | bottom line of.| 000006a0 74 68 65 20 73 63 72 65 65 6e 2c 20 61 73 20 72 |the screen, as r| 000006b0 65 74 75 72 6e 69 6e 67 20 74 6f 20 74 68 61 74 |eturning to that| 000006c0 20 70 6f 73 69 74 69 6f 6e 20 69 6e 20 74 68 65 | position in the| 000006d0 20 74 65 78 74 20 77 6f 75 6c 64 20 72 65 71 75 | text would requ| 000006e0 69 72 65 20 6d 6f 76 69 6e 67 0d 74 6f 20 61 20 |ire moving.to a | 000006f0 70 6f 73 69 74 69 6f 6e 20 6f 66 66 20 74 68 65 |position off the| 00000700 20 62 6f 74 74 6f 6d 20 6f 66 20 74 68 65 20 73 | bottom of the s| 00000710 63 72 65 65 6e 2e 0d 20 20 20 20 20 20 20 20 0d |creen.. .| 00000720
F/+HINT9.m0
F/+HINT9.m1
F/+HINT9.m2
F/+HINT9.m4
F/+HINT9.m5
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