2N2157 semiconductor manufactured by Sylvania, listed as 2N2157 (circa 1979).

2N2156A semiconductor manufactured by Sylvania, listed as 2N2156A (circa 1979).

2N2156 semiconductor manufactured by Sylvania, listed as 2N2156 (circa 1979).

2N2155A semiconductor manufactured by Sylvania, listed as 2N2155A (circa 1979).

2N2155 semiconductor manufactured by Sylvania, listed as 2N2155 (circa 1979).

2N2154A semiconductor manufactured by Sylvania, listed as 2N2154A (circa 1979).

2N2154 semiconductor manufactured by Sylvania, listed as 2N2154 (circa 1979).

2N2153A semiconductor manufactured by Sylvania, listed as 2N2153A (circa 1979).

2N2153 semiconductor manufactured by Sylvania, listed as 2N2153 (circa 1979).

2N2152A semiconductor manufactured by Sylvania, listed as 2N2152A (circa 1979).

2N2152 semiconductor manufactured by Sylvania, listed as 2N2152 (circa 1979).

2N2148 semiconductor manufactured by Sylvania, listed as 2N2148 (circa 1979).

2N2147 semiconductor manufactured by Sylvania, listed as 2N2147 (circa 1979).

2N2146A semiconductor manufactured by Sylvania, listed as 2N2146A (circa 1979).

2N2146 semiconductor manufactured by Sylvania, listed as 2N2146 (circa 1979).

2N2145A semiconductor manufactured by Sylvania, listed as 2N2145A (circa 1979).

2N2145 semiconductor manufactured by Sylvania, listed as 2N2145 (circa 1979).

2N2144A semiconductor manufactured by Sylvania, listed as 2N2144A (circa 1979).

2N2144 semiconductor manufactured by Sylvania, listed as 2N2144 (circa 1979).

2N2143A semiconductor manufactured by Sylvania, listed as 2N2143A (circa 1979).