EPROM images acquired from Rohde & Schwarz ESM500A 570.5012.05 FNr. 875147/0 8 6
by John Miles, KE5FX (jmiles@pop.net), 19-Oct-05

B20 (EPROM I):  Image acquired from 27C128JL, labelled "570.6954.11 B20"
B19 (EPROM II): Image acquired from 2732A-35, labelled "570.6931.11 B19"

Note that B19 is a 24-pin part installed in a 28-pin socket, with IC pin 12 
inserted into socket pin 14.  Socket pins 1, 2, 27, and 28 are left empty.

(Note also that B19 appears to contain nothing but 4,096 zeroes.  All 16KB of this
particular ESM 500A's operating firmware appears to reside on B20.)