Another overlay has the heading "2314/2841 TROS
SAL BITS". There
are two rectangular connectors with cables to connect to whatever this
thing is doing something with:)
2314 is a DASD, 2841 is a control unit, both late S/360 and early S/370
era IBM devices. The rectangular connectors are likely Bus and Tag.
William Donzelli
aw288(a)osfn.org