+++ 1971.g.c. Alpha One 
+++ 1954.a.c. Mohawk Message Repeater Cartridge - 1st USA endless cartridge
+++ 1956.b. Nora T5 - first endless cassette with magnetic tape, also for pre-recorded music
+++ 1987.h. Tesla Transcriber
+++ 1984.j. Nagra JBR cassette 
+++ 1951 c.c. Loewe Optaphon - world's first cassette with magnetic tape 
+++ 1987 .d. caseta/cassette DAT = Digital Audio Tape
+++ 1974(?).g. caseta/cassette Memocord MC990 Ind-X-Matic - single cassette w. built-in counter 
+++ 1958.a.c.- caseta/cassette pt/for Saba TKR15 radiorecorder
+++ 1963 a.c. Philips EL 1903 - first compact-cassette(TM) model
+++ 1971.e.c. Hipac - japanese endless cassette/cartridge inspired from Playtape
+++ 1988.k.c. Pocket Rockers - smallest endless cassette 
+++ 1980.l.c. Philips LDB 4401 - world's first digital minicassette
+++ 1970.m.c. Sanyo Tape Cartridge
+++ 1964.e.c. 3M/Scotch Cantata 700 = greatest audio cassette