IBM 2821 Control Unit
The IBM 2821 Control Unit attaches card readers, card punches and
line printers to the IBM System/360 and IBM System/370 families of computers.
The devices attached are as follows:
Six models of the IBM 2821 Control Unit were available, as follows:
- Model 1 attached one IBM 2540 and one IBM 1403;
- Model 2 attached one IBM 1403;
- Model 3 attached two or three IBM 1403s;
- Model 4 attached one IBM 2540 and one IBM 1404, but only on IBM System/360 models 25, 30, 40 and 50;
- Model 5 attached one IBM 2540 and two or three IBM 1403s; and
- Model 6 attached one IBM 2540.
