Home » Archimedes archive » Acorn User » AU 1994-06.adf » !QTM_Music » !QTMTrack/Docs/Technical
!QTMTrack/Docs/Technical
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 » Acorn User » AU 1994-06.adf » !QTM_Music |
| Filename: | !QTMTrack/Docs/Technical |
| Read OK: | ✔ |
| File size: | 0AFD bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
Technical information for QTM v1.00 by QUANTUM � 1993/4 Phoenix/Quantum
--------------------------------------------------------------------------
As mentioned in the general help file QTM is FAST - I personally have not
found a faster music player (and I have looked around A LOT for one), if you
know of such a player, then tell me!!!
QTM has two sets of sound buffer filling routines, one set for use by
Arm2 computers, and the other for use by Arm3 and better (ie. with cache).
If you are using a computer with cache on, and switch the cache off, QTM
will sense this change automatically and switch over instantly to use the
Arm2 routines (you should not notice any change).
QTM's sound buffer filling routines have been written in a way so that
they are always doing the least amount of work possible - this means that as
the complexity of the samples being output changes, so does the amount of
processor time used by QTM.
Beacuse these times can vary by such a lot, especially on Arm2 machines,
the table of processor usage amounts below shows the average range of times
found on Arm2 computers.
QTM | Arm2 | Arm3 - Arm 2 speeds tested on an
--------+------------+----------- unexpanded A3000
24uS | 17-21% | 13.4% - Arm 3 speeds were from my
--------+------------+----------- 36Mhz Arm3 A310
32uS | 15-17% | 9.1%
--------+------------+----------- These averages were found by
48uS | 11-13% | 6.2% testing the speeds from
--------+------------+----------- several different songs.
64uS | 6-7% | 4.7%
Songs with samples that require more processing (eg. chip samples - very
short looping samples) at varying volumes may add up to 1 or 2% to the Arm2 values given, though most other songs will be within these ranges.
To test QTM's speed for yourself open the !QTMTrack.Extras directory,
which contains several useful programming examples and a VERY accurate speed
tester (read help file in Extras directory).
If you're thinking about using QTM in a game/demo/etc. then you'll want a
copy of the next version of QTM. This new version will not be given a big
release - as in the current version - because it will not be much different
in everyday use, but what it will contain is the...
******** QTM 'Transparent Sound System' ********
This amazing new idea allows you to use any normal sound
controllers (eg. sound FX modules etc...) as though QTM
was not there, though it will still playing along there
in the backgound...
******** Available end of May '94 from QUANTUM ********
(contact me at the address in the !Help file)
Phoenix 00000000 54 65 63 68 6e 69 63 61 6c 20 69 6e 66 6f 72 6d |Technical inform| 00000010 61 74 69 6f 6e 20 66 6f 72 20 51 54 4d 20 76 31 |ation for QTM v1| 00000020 2e 30 30 20 62 79 20 51 55 41 4e 54 55 4d 20 20 |.00 by QUANTUM | 00000030 20 20 a9 20 31 39 39 33 2f 34 20 50 68 6f 65 6e | . 1993/4 Phoen| 00000040 69 78 2f 51 75 61 6e 74 75 6d 0a 2d 2d 2d 2d 2d |ix/Quantum.-----| 00000050 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------| * 00000090 2d 2d 2d 2d 2d 0a 0a 20 20 20 41 73 20 6d 65 6e |-----.. As men| 000000a0 74 69 6f 6e 65 64 20 69 6e 20 74 68 65 20 67 65 |tioned in the ge| 000000b0 6e 65 72 61 6c 20 68 65 6c 70 20 66 69 6c 65 20 |neral help file | 000000c0 51 54 4d 20 69 73 20 46 41 53 54 20 2d 20 49 20 |QTM is FAST - I | 000000d0 70 65 72 73 6f 6e 61 6c 6c 79 20 68 61 76 65 20 |personally have | 000000e0 6e 6f 74 0a 66 6f 75 6e 64 20 61 20 66 61 73 74 |not.found a fast| 000000f0 65 72 20 6d 75 73 69 63 20 70 6c 61 79 65 72 20 |er music player | 00000100 28 61 6e 64 20 49 20 68 61 76 65 20 6c 6f 6f 6b |(and I have look| 00000110 65 64 20 61 72 6f 75 6e 64 20 41 20 4c 4f 54 20 |ed around A LOT | 00000120 66 6f 72 20 6f 6e 65 29 2c 20 69 66 20 79 6f 75 |for one), if you| 00000130 0a 6b 6e 6f 77 20 6f 66 20 73 75 63 68 20 61 20 |.know of such a | 00000140 70 6c 61 79 65 72 2c 20 74 68 65 6e 20 74 65 6c |player, then tel| 00000150 6c 20 6d 65 21 21 21 0a 0a 20 20 20 51 54 4d 20 |l me!!!.. QTM | 00000160 68 61 73 20 74 77 6f 20 73 65 74 73 20 6f 66 20 |has two sets of | 00000170 73 6f 75 6e 64 20 62 75 66 66 65 72 20 66 69 6c |sound buffer fil| 00000180 6c 69 6e 67 20 72 6f 75 74 69 6e 65 73 2c 20 6f |ling routines, o| 00000190 6e 65 20 73 65 74 20 66 6f 72 20 75 73 65 20 62 |ne set for use b| 000001a0 79 0a 41 72 6d 32 20 63 6f 6d 70 75 74 65 72 73 |y.Arm2 computers| 000001b0 2c 20 61 6e 64 20 74 68 65 20 6f 74 68 65 72 20 |, and the other | 000001c0 66 6f 72 20 75 73 65 20 62 79 20 41 72 6d 33 20 |for use by Arm3 | 000001d0 61 6e 64 20 62 65 74 74 65 72 20 28 69 65 2e 20 |and better (ie. | 000001e0 77 69 74 68 20 63 61 63 68 65 29 2e 0a 49 66 20 |with cache)..If | 000001f0 79 6f 75 20 61 72 65 20 75 73 69 6e 67 20 61 20 |you are using a | 00000200 63 6f 6d 70 75 74 65 72 20 77 69 74 68 20 63 61 |computer with ca| 00000210 63 68 65 20 6f 6e 2c 20 61 6e 64 20 73 77 69 74 |che on, and swit| 00000220 63 68 20 74 68 65 20 63 61 63 68 65 20 6f 66 66 |ch the cache off| 00000230 2c 20 51 54 4d 0a 77 69 6c 6c 20 73 65 6e 73 65 |, QTM.will sense| 00000240 20 74 68 69 73 20 63 68 61 6e 67 65 20 61 75 74 | this change aut| 00000250 6f 6d 61 74 69 63 61 6c 6c 79 20 61 6e 64 20 73 |omatically and s| 00000260 77 69 74 63 68 20 6f 76 65 72 20 69 6e 73 74 61 |witch over insta| 00000270 6e 74 6c 79 20 74 6f 20 75 73 65 20 74 68 65 0a |ntly to use the.| 00000280 41 72 6d 32 20 72 6f 75 74 69 6e 65 73 20 28 79 |Arm2 routines (y| 00000290 6f 75 20 73 68 6f 75 6c 64 20 6e 6f 74 20 6e 6f |ou should not no| 000002a0 74 69 63 65 20 61 6e 79 20 63 68 61 6e 67 65 29 |tice any change)| 000002b0 2e 0a 20 20 20 51 54 4d 27 73 20 73 6f 75 6e 64 |.. QTM's sound| 000002c0 20 62 75 66 66 65 72 20 66 69 6c 6c 69 6e 67 20 | buffer filling | 000002d0 72 6f 75 74 69 6e 65 73 20 68 61 76 65 20 62 65 |routines have be| 000002e0 65 6e 20 77 72 69 74 74 65 6e 20 69 6e 20 61 20 |en written in a | 000002f0 77 61 79 20 73 6f 20 74 68 61 74 0a 74 68 65 79 |way so that.they| 00000300 20 61 72 65 20 61 6c 77 61 79 73 20 64 6f 69 6e | are always doin| 00000310 67 20 74 68 65 20 6c 65 61 73 74 20 61 6d 6f 75 |g the least amou| 00000320 6e 74 20 6f 66 20 77 6f 72 6b 20 70 6f 73 73 69 |nt of work possi| 00000330 62 6c 65 20 2d 20 74 68 69 73 20 6d 65 61 6e 73 |ble - this means| 00000340 20 74 68 61 74 20 61 73 0a 74 68 65 20 63 6f 6d | that as.the com| 00000350 70 6c 65 78 69 74 79 20 6f 66 20 74 68 65 20 73 |plexity of the s| 00000360 61 6d 70 6c 65 73 20 62 65 69 6e 67 20 6f 75 74 |amples being out| 00000370 70 75 74 20 63 68 61 6e 67 65 73 2c 20 73 6f 20 |put changes, so | 00000380 64 6f 65 73 20 74 68 65 20 61 6d 6f 75 6e 74 20 |does the amount | 00000390 6f 66 0a 70 72 6f 63 65 73 73 6f 72 20 74 69 6d |of.processor tim| 000003a0 65 20 75 73 65 64 20 62 79 20 51 54 4d 2e 0a 0a |e used by QTM...| 000003b0 20 20 20 42 65 61 63 75 73 65 20 74 68 65 73 65 | Beacuse these| 000003c0 20 74 69 6d 65 73 20 63 61 6e 20 76 61 72 79 20 | times can vary | 000003d0 62 79 20 73 75 63 68 20 61 20 6c 6f 74 2c 20 65 |by such a lot, e| 000003e0 73 70 65 63 69 61 6c 6c 79 20 6f 6e 20 41 72 6d |specially on Arm| 000003f0 32 20 6d 61 63 68 69 6e 65 73 2c 0a 74 68 65 20 |2 machines,.the | 00000400 74 61 62 6c 65 20 6f 66 20 70 72 6f 63 65 73 73 |table of process| 00000410 6f 72 20 75 73 61 67 65 20 61 6d 6f 75 6e 74 73 |or usage amounts| 00000420 20 62 65 6c 6f 77 20 73 68 6f 77 73 20 74 68 65 | below shows the| 00000430 20 61 76 65 72 61 67 65 20 72 61 6e 67 65 20 6f | average range o| 00000440 66 20 74 69 6d 65 73 0a 66 6f 75 6e 64 20 6f 6e |f times.found on| 00000450 20 41 72 6d 32 20 63 6f 6d 70 75 74 65 72 73 2e | Arm2 computers.| 00000460 0a 0a 20 20 20 20 20 20 20 20 20 20 20 51 54 4d |.. QTM| 00000470 20 20 7c 20 20 20 20 41 72 6d 32 20 20 20 20 7c | | Arm2 || 00000480 20 20 20 20 41 72 6d 33 20 20 20 20 20 20 2d 20 | Arm3 - | 00000490 41 72 6d 20 32 20 73 70 65 65 64 73 20 74 65 73 |Arm 2 speeds tes| 000004a0 74 65 64 20 6f 6e 20 61 6e 0a 20 20 20 20 20 20 |ted on an. | 000004b0 20 20 2d 2d 2d 2d 2d 2d 2d 2d 2b 2d 2d 2d 2d 2d | --------+-----| 000004c0 2d 2d 2d 2d 2d 2d 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d |-------+--------| 000004d0 2d 2d 2d 20 20 20 20 20 75 6e 65 78 70 61 6e 64 |--- unexpand| 000004e0 65 64 20 41 33 30 30 30 0a 20 20 20 20 20 20 20 |ed A3000. | 000004f0 20 20 20 32 34 75 53 20 20 7c 20 20 20 31 37 2d | 24uS | 17-| 00000500 32 31 25 20 20 20 7c 20 20 20 31 33 2e 34 25 20 |21% | 13.4% | 00000510 20 20 20 20 20 2d 20 41 72 6d 20 33 20 73 70 65 | - Arm 3 spe| 00000520 65 64 73 20 77 65 72 65 20 66 72 6f 6d 20 6d 79 |eds were from my| 00000530 0a 20 20 20 20 20 20 20 20 2d 2d 2d 2d 2d 2d 2d |. -------| 00000540 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2b 2d |-+------------+-| 00000550 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 20 20 20 20 20 33 |---------- 3| 00000560 36 4d 68 7a 20 41 72 6d 33 20 41 33 31 30 0a 20 |6Mhz Arm3 A310. | 00000570 20 20 20 20 20 20 20 20 20 33 32 75 53 20 20 7c | 32uS || 00000580 20 20 20 31 35 2d 31 37 25 20 20 20 7c 20 20 20 | 15-17% | | 00000590 20 39 2e 31 25 0a 20 20 20 20 20 20 20 20 2d 2d | 9.1%. --| 000005a0 2d 2d 2d 2d 2d 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d 2d |------+---------| 000005b0 2d 2d 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 20 |---+----------- | 000005c0 20 20 20 20 54 68 65 73 65 20 61 76 65 72 61 67 | These averag| 000005d0 65 73 20 77 65 72 65 20 66 6f 75 6e 64 20 62 79 |es were found by| 000005e0 0a 20 20 20 20 20 20 20 20 20 20 34 38 75 53 20 |. 48uS | 000005f0 20 7c 20 20 20 31 31 2d 31 33 25 20 20 20 7c 20 | | 11-13% | | 00000600 20 20 20 36 2e 32 25 20 20 20 20 20 20 20 20 74 | 6.2% t| 00000610 65 73 74 69 6e 67 20 74 68 65 20 73 70 65 65 64 |esting the speed| 00000620 73 20 66 72 6f 6d 0a 20 20 20 20 20 20 20 20 2d |s from. -| 00000630 2d 2d 2d 2d 2d 2d 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d |-------+--------| 00000640 2d 2d 2d 2d 2b 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----+-----------| 00000650 20 20 20 20 20 73 65 76 65 72 61 6c 20 64 69 66 | several dif| 00000660 66 65 72 65 6e 74 20 73 6f 6e 67 73 2e 0a 20 20 |ferent songs.. | 00000670 20 20 20 20 20 20 20 20 36 34 75 53 20 20 7c 20 | 64uS | | 00000680 20 20 20 36 2d 37 25 20 20 20 20 7c 20 20 20 20 | 6-7% | | 00000690 34 2e 37 25 0a 0a 20 20 20 53 6f 6e 67 73 20 77 |4.7%.. Songs w| 000006a0 69 74 68 20 73 61 6d 70 6c 65 73 20 74 68 61 74 |ith samples that| 000006b0 20 72 65 71 75 69 72 65 20 6d 6f 72 65 20 70 72 | require more pr| 000006c0 6f 63 65 73 73 69 6e 67 20 28 65 67 2e 20 63 68 |ocessing (eg. ch| 000006d0 69 70 20 73 61 6d 70 6c 65 73 20 2d 20 76 65 72 |ip samples - ver| 000006e0 79 0a 73 68 6f 72 74 20 6c 6f 6f 70 69 6e 67 20 |y.short looping | 000006f0 73 61 6d 70 6c 65 73 29 20 61 74 20 76 61 72 79 |samples) at vary| 00000700 69 6e 67 20 76 6f 6c 75 6d 65 73 20 6d 61 79 20 |ing volumes may | 00000710 61 64 64 20 75 70 20 74 6f 20 31 20 6f 72 20 32 |add up to 1 or 2| 00000720 25 20 74 6f 20 74 68 65 20 41 72 6d 32 20 76 61 |% to the Arm2 va| 00000730 6c 75 65 73 20 67 69 76 65 6e 2c 20 74 68 6f 75 |lues given, thou| 00000740 67 68 20 6d 6f 73 74 20 6f 74 68 65 72 20 73 6f |gh most other so| 00000750 6e 67 73 20 77 69 6c 6c 20 62 65 20 77 69 74 68 |ngs will be with| 00000760 69 6e 20 74 68 65 73 65 20 72 61 6e 67 65 73 2e |in these ranges.| 00000770 0a 0a 20 20 20 54 6f 20 74 65 73 74 20 51 54 4d |.. To test QTM| 00000780 27 73 20 73 70 65 65 64 20 66 6f 72 20 79 6f 75 |'s speed for you| 00000790 72 73 65 6c 66 20 6f 70 65 6e 20 74 68 65 20 21 |rself open the !| 000007a0 51 54 4d 54 72 61 63 6b 2e 45 78 74 72 61 73 20 |QTMTrack.Extras | 000007b0 64 69 72 65 63 74 6f 72 79 2c 0a 77 68 69 63 68 |directory,.which| 000007c0 20 63 6f 6e 74 61 69 6e 73 20 73 65 76 65 72 61 | contains severa| 000007d0 6c 20 75 73 65 66 75 6c 20 70 72 6f 67 72 61 6d |l useful program| 000007e0 6d 69 6e 67 20 65 78 61 6d 70 6c 65 73 20 61 6e |ming examples an| 000007f0 64 20 61 20 56 45 52 59 20 61 63 63 75 72 61 74 |d a VERY accurat| 00000800 65 20 73 70 65 65 64 0a 74 65 73 74 65 72 20 28 |e speed.tester (| 00000810 72 65 61 64 20 68 65 6c 70 20 66 69 6c 65 20 69 |read help file i| 00000820 6e 20 45 78 74 72 61 73 20 64 69 72 65 63 74 6f |n Extras directo| 00000830 72 79 29 2e 0a 0a 20 20 20 49 66 20 79 6f 75 27 |ry)... If you'| 00000840 72 65 20 74 68 69 6e 6b 69 6e 67 20 61 62 6f 75 |re thinking abou| 00000850 74 20 75 73 69 6e 67 20 51 54 4d 20 69 6e 20 61 |t using QTM in a| 00000860 20 67 61 6d 65 2f 64 65 6d 6f 2f 65 74 63 2e 20 | game/demo/etc. | 00000870 74 68 65 6e 20 79 6f 75 27 6c 6c 20 77 61 6e 74 |then you'll want| 00000880 20 61 0a 63 6f 70 79 20 6f 66 20 74 68 65 20 6e | a.copy of the n| 00000890 65 78 74 20 76 65 72 73 69 6f 6e 20 6f 66 20 51 |ext version of Q| 000008a0 54 4d 2e 20 54 68 69 73 20 6e 65 77 20 76 65 72 |TM. This new ver| 000008b0 73 69 6f 6e 20 77 69 6c 6c 20 6e 6f 74 20 62 65 |sion will not be| 000008c0 20 67 69 76 65 6e 20 61 20 62 69 67 0a 72 65 6c | given a big.rel| 000008d0 65 61 73 65 20 2d 20 61 73 20 69 6e 20 74 68 65 |ease - as in the| 000008e0 20 63 75 72 72 65 6e 74 20 76 65 72 73 69 6f 6e | current version| 000008f0 20 2d 20 62 65 63 61 75 73 65 20 69 74 20 77 69 | - because it wi| 00000900 6c 6c 20 6e 6f 74 20 62 65 20 6d 75 63 68 20 64 |ll not be much d| 00000910 69 66 66 65 72 65 6e 74 0a 69 6e 20 65 76 65 72 |ifferent.in ever| 00000920 79 64 61 79 20 75 73 65 2c 20 62 75 74 20 77 68 |yday use, but wh| 00000930 61 74 20 69 74 20 77 69 6c 6c 20 63 6f 6e 74 61 |at it will conta| 00000940 69 6e 20 69 73 20 74 68 65 2e 2e 2e 0a 0a 20 20 |in is the..... | 00000950 20 20 20 20 20 20 20 20 20 20 2a 2a 2a 2a 2a 2a | ******| 00000960 2a 2a 20 20 51 54 4d 20 27 54 72 61 6e 73 70 61 |** QTM 'Transpa| 00000970 72 65 6e 74 20 53 6f 75 6e 64 20 53 79 73 74 65 |rent Sound Syste| 00000980 6d 27 20 20 2a 2a 2a 2a 2a 2a 2a 2a 0a 0a 20 20 |m' ********.. | 00000990 20 20 20 20 20 20 54 68 69 73 20 61 6d 61 7a 69 | This amazi| 000009a0 6e 67 20 6e 65 77 20 69 64 65 61 20 61 6c 6c 6f |ng new idea allo| 000009b0 77 73 20 79 6f 75 20 74 6f 20 75 73 65 20 61 6e |ws you to use an| 000009c0 79 20 6e 6f 72 6d 61 6c 20 73 6f 75 6e 64 0a 20 |y normal sound. | 000009d0 20 20 20 20 20 20 20 63 6f 6e 74 72 6f 6c 6c 65 | controlle| 000009e0 72 73 20 28 65 67 2e 20 73 6f 75 6e 64 20 46 58 |rs (eg. sound FX| 000009f0 20 6d 6f 64 75 6c 65 73 20 65 74 63 2e 2e 2e 29 | modules etc...)| 00000a00 20 61 73 20 74 68 6f 75 67 68 20 51 54 4d 0a 20 | as though QTM. | 00000a10 20 20 20 20 20 20 20 77 61 73 20 6e 6f 74 20 74 | was not t| 00000a20 68 65 72 65 2c 20 74 68 6f 75 67 68 20 69 74 20 |here, though it | 00000a30 77 69 6c 6c 20 73 74 69 6c 6c 20 70 6c 61 79 69 |will still playi| 00000a40 6e 67 20 61 6c 6f 6e 67 20 74 68 65 72 65 0a 20 |ng along there. | 00000a50 20 20 20 20 20 20 20 69 6e 20 74 68 65 20 62 61 | in the ba| 00000a60 63 6b 67 6f 75 6e 64 2e 2e 2e 0a 20 20 20 20 20 |ckgound.... | 00000a70 20 20 20 0a 20 20 20 20 20 20 20 20 20 2a 2a 2a | . ***| 00000a80 2a 2a 2a 2a 2a 20 20 41 76 61 69 6c 61 62 6c 65 |***** Available| 00000a90 20 65 6e 64 20 6f 66 20 4d 61 79 20 27 39 34 20 | end of May '94 | 00000aa0 66 72 6f 6d 20 51 55 41 4e 54 55 4d 20 2a 2a 2a |from QUANTUM ***| 00000ab0 2a 2a 2a 2a 2a 0a 20 20 20 20 20 20 20 20 20 20 |*****. | 00000ac0 20 20 20 20 20 28 63 6f 6e 74 61 63 74 20 6d 65 | (contact me| 00000ad0 20 61 74 20 74 68 65 20 61 64 64 72 65 73 73 20 | at the address | 00000ae0 69 6e 20 74 68 65 20 21 48 65 6c 70 20 66 69 6c |in the !Help fil| 00000af0 65 29 0a 0a 20 20 50 68 6f 65 6e 69 78 |e).. Phoenix| 00000afd
.