sign in sign up
<<
Home , Dictation machine, Magnetophon, Wire recording

GUIDE to IDENTIFMNG and DATING SOUND RECORDINGS

- Brock Silversides Provincial Archives of Alberta

The technology of sound recording has progressed - dimensions: 4 in. diameter, approximately 4 through only four distinct stages during its 115 year in. long history - the grooved cylinder, the grooved disc, - playing time: 1 minute , and the pitted disc.* There is, - playing speed: variable as cylinder was however, an astonishing variety of developments rotated by hand crank within each stage. For example, there were many - note: unique item (no copies possible) ways that aural information was encoded in each - very fragile: a cylinder could wear out after stage (i.e. the grooves on cylinders or discs could be 6-10 playings indented, cut away, pressed or molded and the - manufactured by Edison Speaking grooves themselves could be formed vertically "hill Co. in 1878 only and dale" or laterally "side to side"). Information has been encoded in both analog and digital modes. 1885 - 1901 : Tire Cylinder Some of these processes were commercially available and some were not. Some were standardized within - wax cylinder introduced by Alexander the manufacturing industry, and some were the Graham BellIChichester BelllCharles Tainter product of a single person or company. AU of the - given the names "" and later proasses overlapped chronologically with others. It "phonocylinder" may seem an overwhelming task to keep track of the - composition: sturdy cardboard tube covered various sound bearing contrivances. with beewax or camuba wax compound into which grooves were cut Relatively accurate dating of sound recordings in - vertical cut grooves 100 to the inch archival, library, or museum collections can be - 3 sizes: 1) regular: 10.5 cm. (4-118 in.) accomplished, however, by placing these processes in long X 5.5 cm. (2-118 in.) diameter: 1889-1929 a chronological context. The following list, while not 2) concert: 10.8 cm. (4-112 in.) long X 12.7 all-inclusive, identifies most of the processes one may cm. (5 in.) diameter: 1899-1901 encounter in North America, as well as giving a 3) dictation: 15.5 cm. (6-118 in.) long X 6 name, dates, dimensions, materials and cm. (2-318 in.) diameter cbteristics, and finally brand names and - playing time: 2 or 4 minutes menufacturers where helpful. - playing speed: 160-200 r.p.m. (standadid for spring motorid or treadle playback * thin U limited to d-only recordiis, not tho~ equipment) recordings which incorporate sound advision. Firoundtnck - packaging: usually packaged inside a mnien ruch 88 the synihronized cybder, disc .nd msgnetic tape slightly larger cardboard tube track, M well M the optical track, videotape advideodisc arc - excluded. by 1889, cylinders were sold commercially making them the first pre-recorded sound carriers - cylinders for home use could be shaved and re-used - first sound recording (that could be played - by 1896, duplicates could be made (25 back) invented by copies to every master) by pantograph - given the name "phonograph" - manufactured by American Graphophone - composition: brass cylinder covered with Co., Columbia Phonograph Co., North American layer of tin foil into which grooves were indented Phonograph Co. (until 1894), Edison National with a stylus Phonograph Co. - 2 colours: creamtwhite: 1885-1890; light - first example of stamping from a reverse bm:1890-1901 metal matrix, which itself was made from original - extremely fragile and subject to distortion acid-etched disc by any heat (including body heat) 12.5 cm. (5 in.) and 18 cm. (7 in.) diameters - lateral cut grooves 1887 - 1888 : The Disc - playing time: 2 minutes - playing speed: variable as gramophone was - flat disc patented by Emile Berliner hand-cranked (approximately 70 r.p.m.) - given the name "Gramophone" - relatively durable - composition: glass base coated with carbon - manufactured by United States Gramophone powder, fixed with lacquer, and then etched with Co., Berliner Gramophone Co., Kammerer & acid where grooves were cut Reinhardt (Germany) - lateral cut grooves - originally intended for children's toys - 18 cm. (7 in.) diameter - playing time: 1-112 minutes - playing speed: varied according to speed used for cutting grooves - 78 r.p.m. discs became industry standard as - note: unique items (no copies possible) mechanized (spring-wound) turntables were extremely scratchy sound standardized - composition: shellac thermoplastic 1888 : The Eadiest Example compound, grooves pressed from master stamper, wide variety of formulations - oldest known extant sound recording, a wax - could be mass produced cylinder - 18 cm. (7 in.) diameter - speech by Canadian Governor-General Lord - lateral cut grooves Stanley at Toronto Industrial Exhibition on 11 - playing time: 2-112 minutes or 4-112 September 1888 minutes - playing speed: 78 r.p.m.(+l-5%) 1888 - 1889 : me Wax Disc - manufactured by Berliner, Columbia, Victor, Edim - introduction of wax gramophone disc by E. - very durable, but become increasingly Berliner brittle with age - composition: zinc base with bees wax mating into which grooves were cut, then etched with chromic acid - 12.5 cm. (5 in.) diameter - fifst magnetic developed by - lateral cut grooves valdew Poulsen - playing time: varied according to speed used - given the name "telegrafm" or for cutting grooves 'telegraphone" - playing speed: variable as gramophone was - composition: rolled carbon steel piano-wire hand cranked on brass spoons or drums - note: unique items (no copies possible) - thickness: 0.010 in. - playing time: varied with length of wire (full spool - 30 minutes) - playing speed: 213 cm. (84 in.) per second - introduction of hard rubber disc by E. (speed very high to compensate for lack of Berliner amplification) - composition: Vulcanite or Durinoid (a - extremely fragile, susceptible to breaks flexible shellac) - unique item (no copies possible) - used mainly as a 1900 - present : Labelling - 85-120 grooves per inch - would become industry standard until - introduction of pre-printed circular paper manufacture discontinued in mid-1950's labels for commercial discs - usually packaged in plain brown kraft paper - included at least recording company, artist, sleeve with hole to show label song title and serial number - after the long-play album was introduced, - prior to this, information was pressed into 78's were called "standard play" disc with stamper 1903 - 1956 : The lbelve-inch Disc 1901 - present : The Double-sided Disc - introduction of 30 cm. (12 in.) disc format - introduction of double-sided discs (grooves by the Gramophone Co. on both sides) by Odeon Records and International - composition: shellac thermoplastic Zonophone Co. - lateral cut grooves - given the name "doubledisc" - playing time: 4 minutes - both vertical and lateral cut grooves - playing speed: 78 r.p.m. - idea originally patented by Colin McKenzie - originally used for longer pieces of classical in Canada, J. E. Wassenich in U.S.A. and A. Petit in U.K. - format later adapted to LP album - single sided discs continued to be manufactured until 1923 1904-1908 : Tire Plastic Disc - plastic disc named "Neophone" 1901-1929 : me Cylinder Em - invented by William Michaelis of England - composition: white celluloid (rigid cellulose introduction of molding process for mass nitrate) on a cardboard base production of cylinders by Edison Co. - 3 diameters: 23 cm. (9 in.); 30 cm. (12 - composition: celluloid (rigid cellulose nitrate in.); 51 cm. (20 in.) 1904-1906 with camphor) - playing times: 4, 6, and 10 minutes (first - vertical cut grooves 200 to the inch long-play records) (approximately half the thickness of wax cylinder - playing speed: 78 r.p.m. (+/-S 96) grooves) - not commercially successful as they had a - playing time: 4 minutes very noisy surface, and were easily warped or - playing speed: 180 r.p.m. broken - colours: black, blue, purple - maker's name and title molded on outer 1906 - 1930 : Grooves edge on one end - packaging: usually packed in cardboard - introduction of discs with "run-out" grooves tube, in wooden tubes (turned on lathe), or in tins (centre to edge) by Path6 Company - peek of popularity for cylinders was 1905 - later given name "centre start disc" (Path6 ceased manufacture in 1906, Columbia in l l in. diameter, double-sided 1910, and Edison Bell in 1915) - there was much confusion in this period as discs with "run-in" grooves continued to be 1901 - 1956 : lRe Ten-inch Disc manufactured

- introduction of 25 cm. (10 in.) disc format - ori@y known as "Red Leaf Records" or "Concert Records" - introduction of "Amberol" cylinder - composition: shellac thermoplastic - composition: thermoplastic called - lateral cut grooves Condensite - playing time: 3 minutes - dimensions: l0 cm. (4 in.) long X 5 cm. (2 - playing speed: 78 r.p.m. (+-5%) in.) diameter - vertical cut grooves 200 Lines to the inch 1930 - [l9551 : Magnetic tape (Anglo-Amerimn) - playing time: 4 minutes - playing speed: 160-180 r.p.m. - introduction of first magnetic tape in - mear produced and comme~idlyavailable England by Louis Blattner, and the U.S. by Bell - mnnufactured by Edison, and played on the Telephone Laboratories Edison 'Ambemla" - playback equipmeat given name - Columbia countered with a similar celluloid "Blattnerphone" cylinder called the "Indestructable Cylinder" - composition: tungsten-steel ribbqn, 6 mm. (114 in.) or 3 mm. (118 in.) wide, 0.08 mm. thick 1912 - 1929 : The Blue Ambeml - @ken over by Marconi Wireless Co. in 1932 and slightly modified - introduction of "Blue Amberol' cylinder - playing tim: 1 reel 30 minutes - composition: bright blue nimllulose - plpying speed: 1.5 metres per second plastic over top of pli~&~-of-pariscon - used by CBC and BBC until wly 1950s - - dimensioas: 10 cm. (4 in.) long X 5 cm. (2 equipment rmPmd "h4iuwni-Stille' in.) diiter - very dunble, but subject to rust - vertical cut gmovss - playing time: 4 minutes 1933 - late 1960s : hwcfiplion discs - playing speed: 160-180 1.p.m. - mssr produced and commercially available, - introduction of transcription discs, espsiPUy mnnufnctured by Edison for brondcssting industry and mrding studios - usuPUypackagedincardboudhrbe11.5 - givem Mme "aceme' or "instantpneous cm. (4-314 in.) long X 6 cm. (2-114 in.) diameter rewdng' or 'lacquer" - not as brittle as the Amberol, and - perfsctedby CecilWatts ncoustically superior - dvminum, copper or ziuc bss with matiag of sthyl ceuulse, dlulosc ncetPtc (with plssticirsrs) or nimuulose lPcqusr into which gmoves e.re. cut introduction of "DidDisc" by Edison - during WWII, the base wns either glass or CornppDy stiff ardbozud since 4sume needed for the - double-sidcd disc war effort - composition: thermoplastic called - 5 dimetem 1) 40 cm. (16 in.); 2) 33 cm. Conddte into whicb grooves wepressed by (13 in.); 3) 30 cm. (12 in.); 4) 25 cm. (10 in.); 5) -stPmper 18cm. (7in.) - 25 cm. (l0 in.) diameter, 0.5 cm. (114 in.) - playing tims: 16 in. (12 mins.); 13 in. (6 thick mins.); 12 in. (5-112 mins.); 10 in. (3-112 mins.); 7 - vertical cut groovfs in. (2-112 mins.) - weighe4l 1 lb. each - playing speeds: 33-113 r.p.m. or 78 r.p.m. - phyhgtim: 4minutes depmaig on cutting speed md amount of - playing speed: 80 r.p.m. information to be put on disc - could only be played on Edisw or Path6 - lwrPl cut gmoves equipmnt, or with an adaptor mechpnism and - disc usunlly has 2 or 3 'drive holes' in sspphiIe stylus cent16 label urr (for Ssvring disc to turntable during groove-cutting pmcew - may be obsnuad by Ipbel) - fiagile, subject to weu each time a stylus is run through grooves. Not intended to be pemment - 'Run-in' grooves (edge to centre) become - plnSticize16 dry out or migrate. over time. industry standud Resulk in mae noise at beat. md embrittlenmtt. - discs with 'nm-out' still occasidy cnckbgmddelmirdonrtworst producsd,butweIe~ - su6ceptible to fungus growth - blanks manufactured by Audio Devices Inc., - very durable (more stable than binder layer) National Hollywood Recording Discs, Presto Recording Corp., Recordio DisclWilcox-Gay, 1945 - 1955 : Later Wire Recordings Recoton Corp., Reeves Soundcraft - introduction of magnetic wire recordings on 1934 - 1948 : Magnetic Tape (Gelmany) a commercial basis (mainly North America) - stainless steel wire magnetized on one side - development of first magnetic tape in wound around a brass core or spool 7 cm. (2.75 Germany by Dr. Gauss and BASF in.) diameter - based on 1929 patent by Fritz Pfleumer .002 - .004 in. diameter - composition: paper tape backing with - playing speed: 51 cm. (20 in.) per second carbonyl iron powder "varnish" - manufactured by General Electric, Brush - 6.5 mm. (114 in.) wide Development Co., Armour Research, Webster - playing time: usually on 35 cm. (14 in.) - fragile, easily broken reels which lasted 1 hour could not be edited - playing sped: 77 cm. (30.3 in.) per second - played back on equipment called 1947 - present : Tape Charneteristics "" by AEG Co. - introduction of magnetic tape to North 1935 - 1970 : Acetate Tapes America on a commercial basis by and 3M - originally cellulose acetate base, then - introduction of cellulose acetate plastic polyvinyl chloride, and finally polyester backing for magnetic tape by BASF - tape widths: 5 cm. (2 in.); 2.5 cm. (1 in.); - original diacetate was quickly superseded by 1.3 cm. (112 in.); .5 cm. (114 in.) triacetate (CTA) - tape thicknesses: .S, .75, 1.0, 1.5 mils - given name "Cellitemor "C-Type" tape - reelsizes:7.5cm.(3in.),12.5cm.(5in.), - dark grey colour 17.5 cm. (7 in.), 26.5 cm. (10-112 in.) - playing time: depends on length - playing speeds: 1) 4.8 cm. (1-718 in.) per - playing speed: l metre per second second; 2) 9.5 cm. (3-314 in.) per second; 3) 19 - low tensile strength, will break before it cm. (7-112 in.) per second; 4) 38 cm. (15 in.) per stretches second; 5) 76.2 cm. (30 in.) per second - sensitive to humidity, becomes "wavy" - pre-recorded reel tapes made available to - prone to shrinkage, flaking public in 1954 - by 1949 had replaced direct-todisc 1936 - present : MeM Tapes recording as it was cheaper, could run for longer periods of time than a disc, and could be edited and - introduction of femc oxide coating for enhanced before magnetic tape by 3M (Minnesota Mining & Mfg. - manufactured by Ampex, Audio Devices Co.) ("Audiotape"), BASF, Be1 Clem Products, Brush - F& or F%O, or Y-F%03 (gamma femc Development Co. ("Soundmirror"), Burgess, oxide) Crescendo, Dr. Andetson's Hi-Fi, E.M.I., - 2 colours: reddish-brown or black Ferrodynamics Corp., Jana, Kramer Magnetics - relatively insensitive to heat Ltd. ("Pan Canada"), Maxell, MSS Recording Co. - chemically stable, good for long-term ("Mastertape"), ORRadio Industries Inc. ("Irish"), storage Radio Shack ("Realisticw,"Supertape"), R.C. A., Reeves Soundcraft Corp., Robins, Sears ("Silvertone"), Shamrock, Sony ,3M ("Scotch"), Trubilt - introduction of polyvinyl chloride plastic backing for magnetic tape - called "PVC" or L-Type" tape 1948 - present : The Long Play Disc - brand names "Mylar", "Estar", "Celanar"

- introduction of long play album disc by 1955 - present : Stereophonic Tapes Columbia given name "Microgroove" or "LP" - introduction of stereo recording for - 2 sizes: 1) 25 cm. (10 in.) discontinued in magnetic tape by E.M.I. in U.K. and Ampex in 1960; 2) 30 cm. (12 in.) became industry standard U.S. - playing time: 25 minutes per side use of 2-track recorder - playing speed: 33-113 r.p.m. 2 channels of audio information - 250-350 grooves per inch (lateral cut) - made of polyvinyl chloride with carbon 1958 - present : Stereophonic Discs black pigment (other colours and translucent LPs also produced) a.k.a. "Vinylite" which was - introduction of stereo recording for LP developed by Union Carbide format by Audio Fidelity Inc., Decca, and - packaged in cardboard sleeve 31 cm. (12- Columbia 112 in.) square - had been pioneered by Westrex Co. in 1957 - degrades when exposed to UV light or heat - two channels of audio information in single - susceptible to thermal cycling (seasonal groove changes): each cycle results in small deformations - given names "Duophonic" (Capitol), which are accumulative, and visible after as few as "Living Stereo" (RCA), "360" Sound" (Columbia), 5 cycles and "" - RCA had experimented with 33-113 r.p.m. - monaural recordings still produced until LP (non-microgroove) in 1931, but it was short- [l9701 lived 1960 - present : Zmpmved Poyester Tape 1949 - present : The Single - introduction of pre-stretched polyethylene - introduction of "single" disc by R.C.A. terepthalate backing for magnetic tape by Dupont - composition: originally polyvinyl chloride, Co. but in 1953 changed to more durable injection- - thickness 1.5 mil. molded polystyrene - became industry standard by 1970 - 17.5 cm. (7 in.) diameter - did not stretch as easily as ordii - lateral cut grooves polyester (more stable than binder layer) - playing time: 3 minutes per side: a variation - unaffected by humidity on the single, the "EP" (Extended play) could play - very stable, even under adverse storage up to 7 minutes per side conditions - playing speed 45 r.p.m. - 250-350 grooves per inch - usually packaged in paper sleeve 18 cm. (7- 114 in.) square with holes to show label - introduction of compact magnetic tape by Phillips - composition: polyester base (.S or .3 mils. thickness) with coatings of ferric oxide, chromium - introduction of polyethylene terepthalate dioxide or metal particles backing for magnetic tape by Dupont Co. - tape: 3.8 mm. (118 in.) wide - given name "polyester" or "PET" - cessette casing: 10 cm. (4 in.) X 6.5 cm. (2- - very thin but very strong 112 in.) X 1 cm. (318 in.) wide - unlikely to break, but could be stretched - packaged in hinged plastic case 11 cm. (4- which rdted in irreversibly distorted signal 114in.) X 6.5 cm. (2-314 in.) X 1.5 cm. (518 in.) - great durability and longevity (more stable wide than binder layer) 11

- standard playing times: 30, 60, 90, 120 1972 to [l9761 : Quad minutes (15, 30, 45, 60 minutes per side), variations available - introduction of quadraphonic recording - playing speed: 4.76 cm. (1-718 in.) per - for LP disc and 8-track tape formats second 4 channels of audio information - first pre-recorded cassettes commercially - given names "SQ" (Columbia), available in 1965 "Quadradisc" (RCA) and "CD-4" (Compatible - "knock-out" holes on top edge a feature to Discreet 4-Channel) prevent re-recording over a tape one wants to save - not commercially successful - manufactured by Ampex, BASF, Denon, Fuji, Irish, Laser, Maxell, Memorex, Phillips, Radio Shack, Robins, Sony, TDK, TEAC, 1971 to [l9721 : nOym@xn LPs Tempus, 3M ("Scotch"), Videosonic - introduction of "Dynaflex" disc by R.C. A. - for LP format - extremely flexible - "unbreakable" - introduction of &track cartridge magnetic tape by Bill Lear - evolved from the enclosed loop cartridge of [l9751 to [l9821 : Picture Discs George Eash (1954) - tape: 1 cm. (114 in.) wide - accelerated marketing of picture discs by - endless loop format on single reel within musical performers cartridge - LP and 45 r.p.m. format - cartridge: 9.5 cm. (4 in.) X 13 cm. (5-118 - lateral cut grooves in.) X 2 cm. (314 in.) wide - LP's packaged in cardboard sleeve 31 cm. - packaged in cardboard sleeve (12-112 in.) with 12-inch hole to show whole disc, - playing time: 4 programs of 12 minutes 45's packaged in clear plastic (polyvinyl chloride) each, for a total 48 minutes pouch 18 cm. (7-114 in.) square - playing speed: 9.5 cm. (3-314 in.) per - first known picture disc precursor dates second from 1905, made of transparent celluloid overlaid - impractical for home recording, so most 8- on lithographed illustrations track tapes are pre-recorded commercially - RCA-Victor produced series of picture discs - can be fast-forwarded, but not reversed in 1933, Famous Records produced discs in 1939, and Vogue Picture Records produced discs 1946-47

1978 - present : MP Topcs - introduction of chromium dioxide coating for magnetic tape by Dupont - introduction of "metal particle" (MP) - given description "low noiselhigh output" coating for magnetic tape by 3M tape - mainly used in compact cassettes - CrO, (higher particle density than ferric - composition: metal alloy 70% iron and 30% oxide) Cobalt, no oxide couplings - silver-black colour - significautly improved frequency response - higher quality recording, became industry standard by 1976 1982 - present : Compact Discs mainly used in compact cassettes - sensitive to heat - may start distorting or - introduction of jointly by losing information above 50" C Phillips and Sony - particles may also change chemically and - perfected in 1978 but not commercially magnetically with prolonged exposure to high available (not manufactured in North America until humidity 1984) - composition: polycarbonate base with cassette casing: 7.25 cm. (2-314 in.) X 5.5 aluminum and acrylic lacquer coatings cm. (2-118 in.) X 1 cm. (112 in.) - 12 cm. (4.7 in.) diameter X 1.2 mm. thick packaged in hinged plastic case: 8 cm. (3- - playing time: 72 minutes 118 in.) X 6 cm. (2-114 in.) X 1.5 cm. (518 in.) - playing speed: 215-500 r.p.m. (continuously standard playing times: 60 and 120 variable as disc is read from centre to edge) minutes, variations available - data bit rate 2.0338 megabits per second playing speed: 8.15 mm. per second - audio information on one side of disc only - - digital recording: information encoded as data bit rate: 2.46 megabits per second microscopic pits is read by laser light beam pickup - packaged in hinged "jewel case", plastic, 14 cm. (5-112 in.) X 12.5 cm. (5 in.) X 1 cm. (318 in.) 1991 - present : "CD Sing& " - note: recordable CD's (CD-R) have been developed which encode information in reflective - introduction of small format compact disc "phasechange" materials (antimony, selenium), and to North America by Sony recordablelerasable CD's (MOD) have been - given name "CD-single" developed using dye-polymers. Neither is - composition: polycarbonate base with commercially available and neither is compatible aluminum and acrylic lacquer coatings with available CD playback units 8 cm. (3-118 in.) diameter - low noise, low distortion, total absence of - playing time: 20 minutes wow and flutter - playing speed: 215-500 r.p.m. (continuously variable as disc is read from centre to 1982 - present : Microwssettes edge) - compressed audio information on one side - polyester base with coating of femc oxide of disc only or chromium dioxide digital recording: information encoded as - tape: 3 mm. (5116 in.) wide microscopic pits is read by laser light beam pickup - cassette casing: 5 cm. (2 in.) X 3.2 cm. (1- - packaged in cardboard sleeve 8.2 cm. (3- 112 in.) X 0.7 cm. (318 in.) thick 114 in.) square - packaged in hinged plastic case - 5.5 cm. (2-114 in.) X 3.8 cm. (1-112 in.) X 1 cm. (7116 in.) 1992 - present : h'gital Compact Casseae thick - playing speeds: 1) 2.4 cm. (1 b.) per - introduction of 'DCC" by Phillips second; 2) 1.2 cm. (113 in.) per second - composition: polyester base with chromium - playing times: 60 (MC*) and 120 (MC- dioxide (video) coating 120) minutes, 30 and 60 minutes per side tape: 3.8 mm. (118 in.) wide respectively - cassette casing: 10 cm. (4 in.) X 6.5 cm. - used chiefly for telephone answMing and (2-112 in.) X 1 cm. (318 in.) wide with sliding dictation machines metal protective covering - manufactured by General Electric, - auto-reverse, cassette cannot be turned Memorex, Pamsonic, Sony over - packaged in hinged plastic case 11 cm. (4- 1990 - present : Tape 114 in.) X 6.5 cm ( 2-314 in.) X 1.5 cm. (518 in.) wide - introduction of R-DAT (rotary digital - compressed audio information in 8 audio-tape) to North America by Sony channels - available in Japan since 1986 - playing times: 90 minutes @W), 120 - composition: magnetic metal particle tape minutes @120), 45 and 60 minutes per side coating, polyester base respectively - tape: 4 mm. (118 in.) wide, 0.5 mil. - playing speed: 4.76 cm. (1-718 in.) per thickness second - low noise, low distortion, total absence of 3. Feldman, L. "Recordable CD: A Technology wow and flutter For the Audio Purist" Sound and Vision, Vol. 8 - DCC player will play back both analog No. 2, MarchIApril 1992, pp.58-59 and digital cassette tapes 4. Feldman, L. "Beyond the Caddy - The 1992 - present : Miniature Compact Disc Mechanics of Sony's MinidiscnAudio,vo1.76 no. 12, December 1992, pp.56-59 - introduction as "Mini disc" by Sony - composition: polycarbonate base with 5. Fontaine, J. "History of Magnetic aluminum and acrylic lacquer coatings RecordingnTheDenradation of Mametic Audio - 6.3 cm. (2.5 in.) diameter Recording (Paris: Bibliotheque Nationale, [1987]) - playing time: 60 minutes (MDW-60) and unpublished translation pp. 1-8 74 minutes (MDW-77) - playing speed: 215-500 r.p.m. 6. Gelatt, R. The Fabulous Phonoeravh: From (continuously variable as disc is read from centre to Edison to Stem (New York: Appleton-Century, edge) 1965) - data bit rate 1.4 megabits per second - compressed audio information on one side 7. Johnson, K. et. al. "A Short History of of disc only Magnetic Recording" The Science of Hinh Fidelity - digital recording: information encoded as 2nd. edit. (Dubuque: KendallIHunt Pub. Co., 1981) microscopic pits is read by laser light beam pickup - packaged in protective plastic "caddy" 7 8. Koenigsberg, A. The Patent Historv of the cm. (2.75 in.) square Phonoma~h1877-1912 (Brooklyn: APM Press, - note: contains a "shockproof" 1990) semiconductor memory chip which eliminates skips or mistracking 9. Moogk, E. Roll Back The Years: Historv of - recordable mini-CDs have been developed Canadian Recorded Sound and Its Leeacv - Genesis using magneto-optical (MO) technology where the to 1930 (Ottawa: National Library of Canada, recording layer encodes information as minute 1975) changes in polarization - low noise, low distortion, total absence of 10. Nunziata, S. "Digital Audio Milestone: DCC wow and flutter Debuts, MD in the Wings" Billboard, 30 May 1992

11. Pickett, A. & Lemcoe, M. J'rewvation And Storane of Sound Recordinns (Washington: Library of Congress, 1959)

For further information, the following literature is 12. Struska, J. "The Historical Development of recommended: Magnetic Tape Recording of Moving Images and Sound" Presemation and Restoration of Moving 1. Chew, V. Talkinn Machines 1877-1914: Imaees and Sound (Brussels: Federation Some Amects of the Early Historv of the Internationale des Archives du Film, 1986) pp. 99- Gramovhone (London: Her Majesty's Stationery 110 Office, 1967) 13. Ward, A. A Manual of Sound Archive 2. "Compact Disc: The 10th Anniversary" Administration (Aldershot: Gower Publishing Co. Billboard Spotlight Billboard, Vol. l04 No. 39, 26 Ltd., 1990) September 1992,28 pp. insert