CR11 Controller

M8291 version

The CR11 Controller was a UNIBUS device controller for the CR11 Card Readers. It used programmed I/O.

The original version was the M829, a dual format card, which was mounted in an SPC slot; it was used with an M105 Address Selector and an M782 Interrupt Control (both tall singles).

M8290 version

Later versions were the M8290 and M8291 quad format cards, also mounted in an SPC slot. The difference between the two is not yet known. All the card versions are program compatible.

Registers

The device has three control and buffer registers, which can be configured to any three sequential word locations in the I/O page; it is normally configured to addresses 777160-777164:

Register	Abbreviation	Address
Status Register	CRS	777160
Data Buffer Register	CRB1	777162
Data Buffer Register Encoded Output	CRB2	777164

In the register contents (below), bits which are read/write or unused are shown in normal font, those which are read-only are in italics, and write-only in bold.

Status Register (CRS)

ERR	CARD DONE	SUPP ERR	RDR CHECK	TIM ERR	RDR ONL	BUSY	RDR RDY	COL RDY	INT ENB	Unused				EJECT	READ
15	14	13	12	11	10	09	08	07	06	05	04	03	02	01	00

Data Buffer Register (CRB1)

Unused				Zones 12-10			Zones 1-9
15	14	13	12	11	10	09	08	07	06	05	04	03	02	01	00

Data Buffer Register - Encoded Output (CRB2)

Unused								Zones 12-8					Encoded Zones 1-7
15	14	13	12	11	10	09	08	07	06	05	04	03	02	01	00

The first buffer register is 12-bit raw data from the card, the second is the compressed Hollerith code (zones 1-7 can have only a single punch, which is encoded in octal in 3 bits; a '0' means 'no punch in any of these').