KE11-E Extended Instruction Set

M7238 card

The KE11-E Extended Instruction Set is the optional PDP-11 Extended Instruction Set for the KD11-A CPU of the PDP-11/40; it implements multiply, divide, and multi-bit shift instructions. It is also used by the KE11-F Floating Instruction Set option.

Physically, it consists of a single hex board, the M7238, which plugs into a pre-wired slot in the CPU backplane, and also connects up to the basic CPU's microcode bus through three over the back BC08-R 40-conductor flat cables which plug into Berg connectors on the M7232 μWord card of the KD11-A.

The KE11-E includes its own microcode ROM, which produces an additional 24 bits width of microcode (to control the data paths and registers on the M7238), but also provides 44 bits of microcode to control registers and datapaths in the basic CPU. (The CPU's microcode is 56 bits wide; the other 12 bits are unused by the KE11-E, and are sent as 0's to the CPU.)

ECO M7238-0004

The diagnostics module CKBI includes a test specifically to check for ECO M7238-0004, it has this to say on the matter:

9.0     PROGRAM DESCRIPTION

        THIS IS A TEST OF THE ASH INSTRUCTION. IT TESTS ASH
        WITH DIFFERENT SHIFT COUNTS IN ALL THE REGISTERS.

9.1     NOTE: THE LAST ROUTINE IN THIS DIAGNOSTIC IS DESIGNED TO
        VERIFY THAT ECO M7238-0004/FCO M7238-0004 (11/40 ONLY)
        HAS BEEN IMPLEMENTED AND IS FUNCTIONING PROPERLY. THIS ECO/FCO
        AFFECTS THE 11/40 EIS (M7238) OPTION ONLY. THUS, ALL 11/40'S
        MUST PASS THIS ROUTINE. ALSO, THE ECO HAS BEEN PHASED INTO
        PRODUCTION SO ALL 11/40'S WITH THE M7238 MODULE MUST PASS THE
        ROUTINE IN MANUFACTURING.
        FIELD SERVICE - ALL M7238 MODULES INCORPORATING THIS ECO OR FCO
        WILL HAVE CS REVISION E OR ABOVE AND MUST PASS THIS ROUTINE.
        ANY M7238 MODULE BELOW THIS CS REVISION LEVEL WILL FAIL THE
        ROUTINE. THIS IS ACCEPTABLE ONLY IF THE CUSTOMER SOFTWARE
        DOES NOT MAKE USE OF THE DECREMENTED OPERAND RESULTING FROM
        THE EXECUTION OF AN EXTENDED INSTRUCTION (ASH, ASHC, MUL OR DIV)
        USING DESTINATION MODE FIVE. IF THE CUSTOMER SOFTWARE DOES
        MAKE USE OF THIS DECREMENTED OPERAND THEN FCO M7238-0004
        (CS REV. E) MUST BE INCORPORATED AND THE LAST ROUTINE IN THE
        DIAGNOSTIC MUST PASS. IF THE FIELD SERVICE TECHNICIAN HAS
        DETERMINED FROM THE ABOVE CRITERIA THAT A PARTICULAR M7238
        MODULE IS NOT REQUIRED TO PASS THE LAST ROUTINE, THEN HE
        MAY INSERT THE APPROPRIATE CODE TO JUMP FROM THE 'SCOPE'
        INSTRUCTION TO 'ENDPAS', THUS BYPASSING THE ROUTINE. SEE
        THE ECO OR FCO FOR MORE INFORMATION.

No known copies of the ECO exist.

External links

• KE11-E and KE11-F instruction set options user's manual (EK-KE11E-OP-001)
• KE11-E and KE11-F instruction set options manual (EK-KE11E-TM-002)
• KE11-E extended instruction set (EIS) option engineering drawings