5 Jun
2002
5 Jun
'02
4:41 a.m.
Do the heaters of the other 5 tubes in the same row
glow? IBM may have
used 6x 25V heaters in series to avoid using a voltage regulator.
IBM used 25L6 because of the large amount of 24 Volt control systems in
there machines for the relays, timers, solenoids, and so forth.
Basically, it was handy.
Keep in mind that it may be intended that the socket is empty - perhaps
for an option not installed in Sellam's machine.
William Donzelli
aw288(a)osfn.org