DA10 Twelve- and Eighteen-Bit Computer Interface

The DA10 Twelve- and Eighteen-Bit Computer Interface connects PDP-10 mainframes to a variety of DEC minicomputers with negative I/O buses, for uses such as communication front ends. These included the 8-bit PDP-8, and 18-bit machines such as the PDP-9.

On the PDP-10 side, it connected to the I/O bus. Thus, it could be connected to KA10 and KI10 CPUs, but only to KL10s with the optional old-style I/O busses. Unlike the DL10, it didn't use DMA, just programmed I/O.

The DA10 is used in the DC68A Data Communication System, which uses a PDP-8/I.

PDP-10 standard instructions

The device name ('CCI') stands for 'Computer-Computer Interface'. The interface has two status bits in each direction:

• From -10 full (which we will call 'F10F')
• From -10 empty ('F10E')
• To -10 full ('T10F')
• To -10 empty ('T10E')

CONO CCI

Unused					Disable self-check	Enable self-check	Clear F10F	Set F10F	Clear F10E	Set F10E	Clear T10F	Set T10F	Clear T10E	Set T10E	Priority interrupt assignment
18	19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35

CONI CCI

Unused						Self-check enabled	Unused	F10F	Unused	F10E	Unused	T10F	Unused	T10E	Priority interrupt assignment
18	19	20	21	22	23	24	25	26	27	28	29	30	31	32	33	34	35