Home » Archimedes archive » Micro User » MU 1991-06.adf » PD-Stuff » Utilities/!ScrollTxt/Scroll
Utilities/!ScrollTxt/Scroll
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 » Archimedes archive » Micro User » MU 1991-06.adf » PD-Stuff |
| Filename: | Utilities/!ScrollTxt/Scroll |
| Read OK: | ✔ |
| File size: | 07FA bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
b BATMAN d PRESENTS : SCROLLTEXT MODULE 1.22 cTHIS IS A SOFTWARE MODULE TO ALLOW YOU TO INCORPORATE A SCROLLTEXT IN YOUR BASIC PROGRAMS. THE MODULE RUNS OFF EVENTS AND DOES NOT AFFECT YOUR BASIC PROGRAMS. ALL OF THE SHAPE DRAWING IS BEING DONE BY A BASIC PROGRAM. SCROLLTEXT CAN COMMUNICATE WITH BASIC PROGRAMS ON A LIMITED LEVEL. SHALL I DEMONSTRATE? O.K. I WILL CHANGE THE SHAPE BEING DISPLAYED ABOVE....x HOW'S THAT? THE BASIC PROGRAM HAS TO REPEATEDLY ISSUE A * COMMAND AND TRAP A CERTAIN TYPE OF ERROR TO ALLOW THE SCROLLTEXT TO COMMUNICATE WITH IT. THE ERROR IS ONLY GENERATED IF THE BASIC PROGRAM CHECKS FOR IT. TIME TO CHANGE THE SHAPES BACK....x AND SO IT CONTINUES. THIS IS ONLY A BRIEF DEMO OF THE SCROLLTEXT. READ THE !HELP FILE IN THE !SCROLLTXT DIRECTORY FOR MORE INFORMATION..... xeNOW FOR A FEW TECHNICAL DETAILS (THOSE OF YOU WHO ARE ALREADY BORED CAN USE ESCAPE NOW!) cTHE MODULEx USES THE 50HZ VSYNC EVENT TO UPDATE THE SCROLLBAR - THIS PREVENTS FLICKER AND GIVES A SMOOTH SCROLL. EVERYx VSYNC, THE EVENT HANDLERx RELOCTES THE BOTTOM 32 LINES OF THE SCREEN 4 BYTES TO THE LEFT AND DISPLAYS A SLICE OF THE NEW CHARACTER. THE RELOCATION IS DONE BY LOADING 40 BYTES OF SCREEN MEMORY INTO REGISTERS 0 TO 9 USING LDMFA, THEN WRITING THEM BACK 4 BYTES TO THE LEFxT USING STMFA. R10 IS USED AS A STACK POINTER WHICH I ADD TO AND SUBTRACT FROM IN ORDER TO COVER THE WHOLE OF THE BOTTOM 32 LINES. R11 IS USED AS A COUNTER FOR THE 32 LINES. EVERYx TIME THE SCROLLBAR IS MOVED, THE PLOT ROUTINE IS CALLED. TO GIVE SPEED CONTROL, THE NUMBER OF TIMES THE SCROLL-PLOT ROUTINE IS CALLED IS CHANGED FROM ONCE TO TWICE TO THREE TIMES EVERY VSYNC. AT THE TOP SCROLLING SPEED, 1.5 MEGABYTES IS RELOCTED EVERY SECOND OFF THE VSYNC EVENT - THIS IS A TESTAMENT TO THE SPEED OF THE +RCHIMEDES AS MOST OF THE SYSTEM TIME IS xSTILL AVAILABLE FOR FORGROUND TASKS. THAT REMINDS ME, IN THIS FONT, THE PLUS SYMBOL COMES OUT AS A + SYMBOL. x bWELL, TIME TO WRAP...... a
00000000 20 20 20 20 20 62 20 20 42 41 54 4d 41 4e 20 20 | b BATMAN | 00000010 64 20 50 52 45 53 45 4e 54 53 20 3a 20 20 20 20 |d PRESENTS : | 00000020 53 43 52 4f 4c 4c 54 45 58 54 20 4d 4f 44 55 4c |SCROLLTEXT MODUL| 00000030 45 20 31 2e 32 32 20 20 20 20 20 20 20 20 20 20 |E 1.22 | 00000040 20 20 63 54 48 49 53 20 49 53 20 41 20 53 4f 46 | cTHIS IS A SOF| 00000050 54 57 41 52 45 20 4d 4f 44 55 4c 45 20 54 4f 20 |TWARE MODULE TO | 00000060 41 4c 4c 4f 57 20 59 4f 55 20 54 4f 20 49 4e 43 |ALLOW YOU TO INC| 00000070 4f 52 50 4f 52 41 54 45 20 41 20 53 43 52 4f 4c |ORPORATE A SCROL| 00000080 4c 54 45 58 54 20 49 4e 20 59 4f 55 52 20 42 41 |LTEXT IN YOUR BA| 00000090 53 49 43 20 50 52 4f 47 52 41 4d 53 2e 20 54 48 |SIC PROGRAMS. TH| 000000a0 45 20 4d 4f 44 55 4c 45 20 52 55 4e 53 20 4f 46 |E MODULE RUNS OF| 000000b0 46 20 45 56 45 4e 54 53 20 41 4e 44 20 44 4f 45 |F EVENTS AND DOE| 000000c0 53 20 4e 4f 54 20 41 46 46 45 43 54 20 59 4f 55 |S NOT AFFECT YOU| 000000d0 52 20 42 41 53 49 43 20 50 52 4f 47 52 41 4d 53 |R BASIC PROGRAMS| 000000e0 2e 20 41 4c 4c 20 4f 46 20 54 48 45 20 53 48 41 |. ALL OF THE SHA| 000000f0 50 45 20 44 52 41 57 49 4e 47 20 49 53 20 42 45 |PE DRAWING IS BE| 00000100 49 4e 47 20 44 4f 4e 45 20 42 59 20 41 20 42 41 |ING DONE BY A BA| 00000110 53 49 43 20 50 52 4f 47 52 41 4d 2e 20 20 20 20 |SIC PROGRAM. | 00000120 53 43 52 4f 4c 4c 54 45 58 54 20 43 41 4e 20 43 |SCROLLTEXT CAN C| 00000130 4f 4d 4d 55 4e 49 43 41 54 45 20 57 49 54 48 20 |OMMUNICATE WITH | 00000140 42 41 53 49 43 20 50 52 4f 47 52 41 4d 53 20 4f |BASIC PROGRAMS O| 00000150 4e 20 41 20 4c 49 4d 49 54 45 44 20 4c 45 56 45 |N A LIMITED LEVE| 00000160 4c 2e 20 20 53 48 41 4c 4c 20 49 20 44 45 4d 4f |L. SHALL I DEMO| 00000170 4e 53 54 52 41 54 45 3f 20 20 20 4f 2e 4b 2e 20 |NSTRATE? O.K. | 00000180 49 20 57 49 4c 4c 20 43 48 41 4e 47 45 20 54 48 |I WILL CHANGE TH| 00000190 45 20 53 48 41 50 45 20 42 45 49 4e 47 20 44 49 |E SHAPE BEING DI| 000001a0 53 50 4c 41 59 45 44 20 41 42 4f 56 45 2e 2e 2e |SPLAYED ABOVE...| 000001b0 2e 78 20 20 20 48 4f 57 27 53 20 54 48 41 54 3f |.x HOW'S THAT?| 000001c0 20 20 20 20 20 54 48 45 20 42 41 53 49 43 20 50 | THE BASIC P| 000001d0 52 4f 47 52 41 4d 20 48 41 53 20 54 4f 20 52 45 |ROGRAM HAS TO RE| 000001e0 50 45 41 54 45 44 4c 59 20 49 53 53 55 45 20 41 |PEATEDLY ISSUE A| 000001f0 20 2a 20 43 4f 4d 4d 41 4e 44 20 41 4e 44 20 54 | * COMMAND AND T| 00000200 52 41 50 20 41 20 43 45 52 54 41 49 4e 20 54 59 |RAP A CERTAIN TY| 00000210 50 45 20 4f 46 20 45 52 52 4f 52 20 54 4f 20 41 |PE OF ERROR TO A| 00000220 4c 4c 4f 57 20 54 48 45 20 53 43 52 4f 4c 4c 54 |LLOW THE SCROLLT| 00000230 45 58 54 20 54 4f 20 43 4f 4d 4d 55 4e 49 43 41 |EXT TO COMMUNICA| 00000240 54 45 20 57 49 54 48 20 49 54 2e 20 54 48 45 20 |TE WITH IT. THE | 00000250 45 52 52 4f 52 20 49 53 20 4f 4e 4c 59 20 47 45 |ERROR IS ONLY GE| 00000260 4e 45 52 41 54 45 44 20 49 46 20 54 48 45 20 42 |NERATED IF THE B| 00000270 41 53 49 43 20 50 52 4f 47 52 41 4d 20 43 48 45 |ASIC PROGRAM CHE| 00000280 43 4b 53 20 46 4f 52 20 49 54 2e 20 20 20 54 49 |CKS FOR IT. TI| 00000290 4d 45 20 54 4f 20 43 48 41 4e 47 45 20 54 48 45 |ME TO CHANGE THE| 000002a0 20 53 48 41 50 45 53 20 42 41 43 4b 2e 2e 2e 2e | SHAPES BACK....| 000002b0 78 20 41 4e 44 20 53 4f 20 49 54 20 43 4f 4e 54 |x AND SO IT CONT| 000002c0 49 4e 55 45 53 2e 20 20 20 54 48 49 53 20 49 53 |INUES. THIS IS| 000002d0 20 4f 4e 4c 59 20 41 20 42 52 49 45 46 20 44 45 | ONLY A BRIEF DE| 000002e0 4d 4f 20 4f 46 20 54 48 45 20 53 43 52 4f 4c 4c |MO OF THE SCROLL| 000002f0 54 45 58 54 2e 20 52 45 41 44 20 54 48 45 20 21 |TEXT. READ THE !| 00000300 48 45 4c 50 20 46 49 4c 45 20 49 4e 20 54 48 45 |HELP FILE IN THE| 00000310 20 21 53 43 52 4f 4c 4c 54 58 54 20 44 49 52 45 | !SCROLLTXT DIRE| 00000320 43 54 4f 52 59 20 46 4f 52 20 4d 4f 52 45 20 49 |CTORY FOR MORE I| 00000330 4e 46 4f 52 4d 41 54 49 4f 4e 2e 2e 2e 2e 2e 20 |NFORMATION..... | 00000340 20 20 20 20 20 20 20 20 20 20 78 65 4e 4f 57 20 | xeNOW | 00000350 46 4f 52 20 41 20 46 45 57 20 54 45 43 48 4e 49 |FOR A FEW TECHNI| 00000360 43 41 4c 20 44 45 54 41 49 4c 53 20 28 54 48 4f |CAL DETAILS (THO| 00000370 53 45 20 4f 46 20 59 4f 55 20 57 48 4f 20 41 52 |SE OF YOU WHO AR| 00000380 45 20 41 4c 52 45 41 44 59 20 42 4f 52 45 44 20 |E ALREADY BORED | 00000390 43 41 4e 20 55 53 45 20 45 53 43 41 50 45 20 4e |CAN USE ESCAPE N| 000003a0 4f 57 21 29 20 20 20 20 20 20 20 20 20 20 20 63 |OW!) c| 000003b0 54 48 45 20 4d 4f 44 55 4c 45 78 20 55 53 45 53 |THE MODULEx USES| 000003c0 20 54 48 45 20 35 30 48 5a 20 56 53 59 4e 43 20 | THE 50HZ VSYNC | 000003d0 45 56 45 4e 54 20 54 4f 20 55 50 44 41 54 45 20 |EVENT TO UPDATE | 000003e0 54 48 45 20 53 43 52 4f 4c 4c 42 41 52 20 2d 20 |THE SCROLLBAR - | 000003f0 54 48 49 53 20 50 52 45 56 45 4e 54 53 20 46 4c |THIS PREVENTS FL| 00000400 49 43 4b 45 52 20 41 4e 44 20 47 49 56 45 53 20 |ICKER AND GIVES | 00000410 41 20 53 4d 4f 4f 54 48 20 53 43 52 4f 4c 4c 2e |A SMOOTH SCROLL.| 00000420 20 20 20 45 56 45 52 59 78 20 56 53 59 4e 43 2c | EVERYx VSYNC,| 00000430 20 54 48 45 20 45 56 45 4e 54 20 48 41 4e 44 4c | THE EVENT HANDL| 00000440 45 52 78 20 52 45 4c 4f 43 54 45 53 20 54 48 45 |ERx RELOCTES THE| 00000450 20 42 4f 54 54 4f 4d 20 33 32 20 4c 49 4e 45 53 | BOTTOM 32 LINES| 00000460 20 4f 46 20 54 48 45 20 53 43 52 45 45 4e 20 34 | OF THE SCREEN 4| 00000470 20 42 59 54 45 53 20 54 4f 20 54 48 45 20 4c 45 | BYTES TO THE LE| 00000480 46 54 20 41 4e 44 20 44 49 53 50 4c 41 59 53 20 |FT AND DISPLAYS | 00000490 41 20 53 4c 49 43 45 20 4f 46 20 54 48 45 20 4e |A SLICE OF THE N| 000004a0 45 57 20 43 48 41 52 41 43 54 45 52 2e 20 20 20 |EW CHARACTER. | 000004b0 54 48 45 20 52 45 4c 4f 43 41 54 49 4f 4e 20 49 |THE RELOCATION I| 000004c0 53 20 44 4f 4e 45 20 42 59 20 4c 4f 41 44 49 4e |S DONE BY LOADIN| 000004d0 47 20 34 30 20 42 59 54 45 53 20 4f 46 20 53 43 |G 40 BYTES OF SC| 000004e0 52 45 45 4e 20 4d 45 4d 4f 52 59 20 49 4e 54 4f |REEN MEMORY INTO| 000004f0 20 52 45 47 49 53 54 45 52 53 20 30 20 54 4f 20 | REGISTERS 0 TO | 00000500 39 20 55 53 49 4e 47 20 4c 44 4d 46 41 2c 20 54 |9 USING LDMFA, T| 00000510 48 45 4e 20 57 52 49 54 49 4e 47 20 54 48 45 4d |HEN WRITING THEM| 00000520 20 42 41 43 4b 20 34 20 42 59 54 45 53 20 54 4f | BACK 4 BYTES TO| 00000530 20 54 48 45 20 4c 45 46 78 54 20 55 53 49 4e 47 | THE LEFxT USING| 00000540 20 53 54 4d 46 41 2e 20 52 31 30 20 49 53 20 55 | STMFA. R10 IS U| 00000550 53 45 44 20 41 53 20 41 20 53 54 41 43 4b 20 50 |SED AS A STACK P| 00000560 4f 49 4e 54 45 52 20 57 48 49 43 48 20 49 20 41 |OINTER WHICH I A| 00000570 44 44 20 54 4f 20 41 4e 44 20 53 55 42 54 52 41 |DD TO AND SUBTRA| 00000580 43 54 20 46 52 4f 4d 20 49 4e 20 4f 52 44 45 52 |CT FROM IN ORDER| 00000590 20 54 4f 20 43 4f 56 45 52 20 54 48 45 20 57 48 | TO COVER THE WH| 000005a0 4f 4c 45 20 4f 46 20 54 48 45 20 42 4f 54 54 4f |OLE OF THE BOTTO| 000005b0 4d 20 33 32 20 4c 49 4e 45 53 2e 20 52 31 31 20 |M 32 LINES. R11 | 000005c0 49 53 20 55 53 45 44 20 41 53 20 41 20 43 4f 55 |IS USED AS A COU| 000005d0 4e 54 45 52 20 46 4f 52 20 54 48 45 20 33 32 20 |NTER FOR THE 32 | 000005e0 4c 49 4e 45 53 2e 20 20 20 45 56 45 52 59 78 20 |LINES. EVERYx | 000005f0 54 49 4d 45 20 54 48 45 20 53 43 52 4f 4c 4c 42 |TIME THE SCROLLB| 00000600 41 52 20 49 53 20 4d 4f 56 45 44 2c 20 54 48 45 |AR IS MOVED, THE| 00000610 20 50 4c 4f 54 20 52 4f 55 54 49 4e 45 20 49 53 | PLOT ROUTINE IS| 00000620 20 43 41 4c 4c 45 44 2e 20 20 54 4f 20 47 49 56 | CALLED. TO GIV| 00000630 45 20 53 50 45 45 44 20 43 4f 4e 54 52 4f 4c 2c |E SPEED CONTROL,| 00000640 20 54 48 45 20 4e 55 4d 42 45 52 20 4f 46 20 54 | THE NUMBER OF T| 00000650 49 4d 45 53 20 54 48 45 20 53 43 52 4f 4c 4c 2d |IMES THE SCROLL-| 00000660 50 4c 4f 54 20 52 4f 55 54 49 4e 45 20 49 53 20 |PLOT ROUTINE IS | 00000670 43 41 4c 4c 45 44 20 49 53 20 43 48 41 4e 47 45 |CALLED IS CHANGE| 00000680 44 20 46 52 4f 4d 20 4f 4e 43 45 20 54 4f 20 54 |D FROM ONCE TO T| 00000690 57 49 43 45 20 54 4f 20 54 48 52 45 45 20 54 49 |WICE TO THREE TI| 000006a0 4d 45 53 20 45 56 45 52 59 20 56 53 59 4e 43 2e |MES EVERY VSYNC.| 000006b0 20 41 54 20 54 48 45 20 54 4f 50 20 53 43 52 4f | AT THE TOP SCRO| 000006c0 4c 4c 49 4e 47 20 53 50 45 45 44 2c 20 31 2e 35 |LLING SPEED, 1.5| 000006d0 20 4d 45 47 41 42 59 54 45 53 20 49 53 20 52 45 | MEGABYTES IS RE| 000006e0 4c 4f 43 54 45 44 20 45 56 45 52 59 20 53 45 43 |LOCTED EVERY SEC| 000006f0 4f 4e 44 20 4f 46 46 20 54 48 45 20 56 53 59 4e |OND OFF THE VSYN| 00000700 43 20 45 56 45 4e 54 20 2d 20 54 48 49 53 20 49 |C EVENT - THIS I| 00000710 53 20 41 20 54 45 53 54 41 4d 45 4e 54 20 54 4f |S A TESTAMENT TO| 00000720 20 54 48 45 20 53 50 45 45 44 20 4f 46 20 54 48 | THE SPEED OF TH| 00000730 45 20 2b 52 43 48 49 4d 45 44 45 53 20 41 53 20 |E +RCHIMEDES AS | 00000740 4d 4f 53 54 20 4f 46 20 54 48 45 20 53 59 53 54 |MOST OF THE SYST| 00000750 45 4d 20 54 49 4d 45 20 49 53 20 78 53 54 49 4c |EM TIME IS xSTIL| 00000760 4c 20 41 56 41 49 4c 41 42 4c 45 20 46 4f 52 20 |L AVAILABLE FOR | 00000770 46 4f 52 47 52 4f 55 4e 44 20 54 41 53 4b 53 2e |FORGROUND TASKS.| 00000780 20 20 20 54 48 41 54 20 52 45 4d 49 4e 44 53 20 | THAT REMINDS | 00000790 4d 45 2c 20 49 4e 20 54 48 49 53 20 46 4f 4e 54 |ME, IN THIS FONT| 000007a0 2c 20 54 48 45 20 50 4c 55 53 20 53 59 4d 42 4f |, THE PLUS SYMBO| 000007b0 4c 20 43 4f 4d 45 53 20 4f 55 54 20 41 53 20 41 |L COMES OUT AS A| 000007c0 20 2b 20 53 59 4d 42 4f 4c 2e 20 20 20 20 20 78 | + SYMBOL. x| 000007d0 20 20 20 20 20 62 57 45 4c 4c 2c 20 54 49 4d 45 | bWELL, TIME| 000007e0 20 54 4f 20 57 52 41 50 2e 2e 2e 2e 2e 2e 20 20 | TO WRAP...... | 000007f0 20 20 20 20 20 20 20 20 20 61 | a| 000007fa
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