KD11-E/EA microcode

The engineering drawings for the KD11-E CPU and KD11-EA CPU provide nice flow charts for the microcode in these CPUs; with one tiny exception, the microcode in the two is identical. (The KD11-EA contains additional microcode associated with the FP11-A Floating-Point Processor, which is not covered here.)

The difference is that the microinstruction 17-JJ is stored in location 002 in the KD11-E, and location 0744 in the KD11-EA. The reason for the change is unknown. Also, a dump of the KD11-EA microcode gives a different 'next microinstuction', from that given in the prints, for microinstruction 26-L (location 646); the prints show 9-F (location 320) as the next, but the dump gives 745. Again, the reason is unknown.

Flow chart index

The instructions/functionality covered on each page are as follows:

Page	Contents
2	Instruction fetch and dispatch
3	Double op, source fetch
4	MOV
5	Double op, byte or SUB
6	Double op, destination fetch
7	Single op, modified dest
8	Single op, non-modified dest
9	JMP
10	JSR
11	SWAB
12	Shift, rotate
13	MFPI
14	MTPI
15	MTPS
16	MFPS
17	MARK, BR, RTS, CLx, SEx, SOB, RTI, RTT, NEG, WAIT, RESET
18	MUL/DIV
19	MUL
20	MUL
21	DIV
22	DIV
23	ASH/ASHC
24	Shift right
25	Shift left
26	Power on, trap

Microcode

The following table, indexed by microinstruction number (in octal), gives the location of each microinstruction in the flow diagrams, the next microinstruction(s), and the operation performed by that microinstruction.

The microengine of the KD11-E/EA uses a technique called a 'branch microtest' (abbreviated to 'BUT' in the drawings), where the 'next microinstruction' field (in each microinstruction - there is no 'micro-PC') can be OR'd with various bits provided by the logic in the KD11-E/EA, to provide conditional branching. More than one bit at a time can be OR'd, thereby providing multi-way branching.

In the table below, for every microinstruction which can have variation as to the next microinstruction, all possible 'next microinstruction' destinations are listed. Note that depending on the bit(s) being tested, various bits of the 'next microinstruction' address may be set.

This can result in rather odd code layout, since a multi-way branch may require microinstructions to be scattered throughout the address space, with a fixed numerical relationship among their addresses - the exact relationship depending on which bit is being tested.

One microinstruction (015), the main dispatch in instruction decoding, greatly extends the technique, with the aid of an instruction decode ROM, so the next microinstruction in its case may be one of dozens. They are mostly arranged in groups of eight, with one of each group for each addressing mode in the operands. (In the table below, such a destination is notated as 'YYx'.)

During the transcription of this information, a number of errors in the drawings were found - places were two different microinstructions were assigned to the same location. These have been corrected (and checked against a dump of the microcode).

μinstruction	μcode flow diagram location	next μinst	Operation
000	2-A	016,017	Service intr/trap, store vector
001	26-M	432	Move PC to B
002
003	17-LL	000	Initialize system for 150msec
004	17-L	525	Destination register to PC
005	13-E	371	Fetch destination address, enable previous mode
006	17-R	541	PSW to R12
007	17-X	542	PSW to R12
010	14-D	644	Fetch word from top of stack
011	17-EE	645	Fetch top of stack
012	17-NN	014	No operation
013	17-OO	460	Vector to R15
014	17-MM	012,013	Service interrupt/trab, fetch vector
015	2-C	+	Increment PC, ubranch on instruction
016	2-B	015	Fetch next instruction, load into IR
017	26-A	460	Move vector to R15
020	17-A	553	Sign extend BREG
021	9-A	000	Jump address to PC
022	9-C	317	Jump address to BREG
023	9-D	317	Fetch jump address
024	9-B	021	Decrement RDST, enable stack overflow
025	9-G	321	Decrement RDST, enable stack overflow
026	9-I	322	Fetch index data
027	9-L	324	Fetch index data
030	11-A	343	Swap destination operand to R12
031	11-C	355	Fetch swapped destination operand
032	11-E	344	Fetch swapped destination operand
033	11-G	345	Fetch destination address
034	11-D	031	Decrement RDST, enable stack overflow
035	11-I	346	Decrement RDST, enable stack overflow
036	11-K	347	Fetch index data
037	11-N	351	Fetch index data
040	7-A	000	Operate and load condition codes
041	7-B	217	Fetch destination operand
042	7-D	275	Fetch destination operand
043	7-F	276	Fetch destination address
044	7-C	041	Decrement RDST, enable stack overflow
045	7-H	277	Decrement RDST, enable stack overflow
046	7-K	301	Fetch index data
047	7-M	303	Fetch index data
050	4-A	000	Operate and load condition codes
051	4-B	217	Set up destination address
052	4-P	217	Set up destination address, increment RDST
053	4-F	141	Fetch destination address
054	4-C	051	Decrement RDST, enable stack overflow
055	4-H	142	Decrement RDST, enable stack overflow
056	4-J	144	Fetch index data
057	4-M	146	Fetch index data
060	6-A	265	Destination operand to BREG
061	6-B	265	Fetch destination operand
062	6-D	263	Fetch destination operand
063	6-F	264	Fetch destination address
064	6-C	061	Decrement RDST, enable stack overflow
065	6-I	266	Decrement RDST, enable stack overflow
066	6-L	662	Fetch index data
067	6-O	272	Fetch index data
070	5-A	050	Destination operand to BREG
071	5-B	217	Fetch destination operand
072	5-D	242	Fetch destination operand
073	5-F	243	Fetch destination address
074	5-C	071	Decrement RDST, enable stack overflow
075	5-H	244	Decrement RDST, enable stack overflow
076	5-K	246	Fetch index data
077	5-N	661	Fetch index data
100	13-A	463	Destination data to R12, enable previous mode
101	13-B	455	Move destination address to R12
102	13-D	005	Move destination address to R12
103	13-G	372	Fetch destination address
104	13-C	101	Decrement RDST, enable stack overflow
105	13-I	373	Decrement RDST, enable stack overflow
106	13-K	374	Fetch index data
107	13-N	376	Fetch index data
110	3-A	05x, 06x. 07x	Source operand to R12 and BREG
111	3-B	05x, 06x. 07x	Fetch source operand
112	3-D	205	Fetch source operand
113	3-F	206	Fetch source address
114	3-C	111	Decrement RSRC, enable stack overflow
115	3-H	207	Decrement RSRC, enable stack overflow
116	3-K	212	Fetch index data
117	3-N	214	Fetch index data
120	15-A	675	Destination operand to R12 and BREG
121	15-F	675	Fetch destination operand
122	15-H	663	Fetch destination operand
123	15-J	664	Fetch destination address
124	15-G	121	Decrement RDST, enable stack overflow
125	15-M	665	Decrement RDST, enable stack overflow
126	15-O	667	Fetch index data
127	15-R	672	Fetch index data
130	16-A	705	PSW data to R12
131	16-C	706	Place destination address on bus address lines
132	16-F	706	Destination address to bus, increment RDST
133	16-G	710	Fetch destination address
134	16-E	131	Decrement RDST, enable stack overflow
135	16-J	711	Decrement RDST, enable stack overflow
136	16-L	712	Fetch index data
137	16-O	714	Fetch index data
140	17-U	210	RDST to BREG
141	4-G	143	Increment RDST
142	4-I	143	Fetch destination address
143	4-Q	217	Setup destination address, enable KT maintenance
144	4-K	145	Increment PC
145	4-L	143	Determine destination address
146	4-N	147	Increment PC
147	4-O	241	Determine address of destination address
150	17-KK	07x	Zero R12
151	10-A	336	Jump address to BREG
152	10-C	327	Jump address to BREG
153	10-D	327	Fetch jump address
154	10-B	336	Decrement RDST, jump address to BREG
155	10-F	330	Decrement RDST, enable stack overflow
156	10-H	331	Fetch index data
157	10-K	333	Fetch index data
160	8-A	000	Operate on operand, load condition codes
161	8-B	265	Fetch destination operand
162	8-D	306	Fetch destination operand
163	8-F	307	Fetch destination address
164	8-C	161	Decrement RDST, enable stack overflow
165	8-H	310	Decrement RDST, enable stack overflow
166	8-K	312	Fetch index data
167	8-N	314	Fetch index data
170	12-A	356	Destination operand to BREG
171	12-C	370	Fetch destination operand
172	12-E	357	Fetch destination operand
173	12-G	360	Fetch destination addressa
174	12-D	171	Decrement RDST, enable stack overflow
175	12-I	361	Decrement RDST, enable stack overflow
176	12-L	363	Fetch index data
177	12-O	365	Fetch index data
200	17-I	522	Sign extend BREG
201	26-FF	202	Set R15 to 26
202	26-GG	577	Fetch new PSW
203	17-Q	000	Operate, set condition codes
204	17-W	000	Operate, set condition codes
205	3-E	05x,06x,07x	Increment RSRC
206	3-G	211	Increment RSRC
207	3-I	211	Fetch source address
210	17-T	000	Operate, send condition codes
211	3-J	05x,06x,07x	Fetch source operand
212	3-L	213	Increment PC
213	3-M	211	Determine source address
214	3-O	215	Increment PC
215	3-P	216	Determine address of source address
216	3-Q	211	Fetch source address
217	4-E	000	Get destination data and store, enable KT maintenance
220	18-A	602	Fetch multiplicand/divisor
221	18-B	602	Fetch multiplicand/divisor
222	18-D	563	Fetch multiplicand/divisor
223	18-F	565	Fetch destination address
224	18-C	221	Decrement RDST, enable stack overflow
225	18-H	567	Decrement RDST, enable stack overflow
226	18-J	571	Fetch index data
227	18-M	575	Fetch index data
230	23-A	633	Fetch shift count
231	23-B	633	Fetch shift count
232	23-D	621	Fetch shift count
233	23-F	622	Fetch destination address
234	23-C	231	Decrement RDST, enable stack overflow
235	23-H	624	Decrement RDST, enable stack overflow
236	23-J	625	Fetch index data
237	23-M	627	Fetch index data
240	17-V	204	RSRC to BREG
241	4-P	143	Fetch destination address
242	5-E	217	Increment RDST
243	5-G	245	Increment RDST
244	5-I	245	Fetch destination address
245	5-J	217	Fetch destination operand
246	5-L	247	Increment PC
247	5-M	245	Determine destination address
250	14-A	000	Move data to desination register
251	14-B	513	Move destination address to R13
252	14-F	474	Move destination address to R13
253	14-H	474	Fetch destination address
254	14-C	251	Decrement RDST, enable stack overflow
255	14-I	475	Decrement RDST, enable stack overflow
256	14-K	476	Fetch index data
257	14-N	506	Fetch index data
260	17-Z	700,702	Decrement RSRC, branch on 0
261	5-P	262	Determine address of destination address
262	5-Q	245	Fetch destination address
263	6-E	265	Increment RDST
264	6-G	267	Increment RDST
265	6-H	000	Operate and load condition codes
266	6-J	267	Fetch destination address
267	6-K	265	Fetch destination operand
270	17-P	203	RDEST to BREG
271	6-N	267	Determine destination address
272	6-P	273	Increment PC
273	6-Q	274	Determine address of destination address
274	6-R	267	Fetch destination address
275	7-E	217	Increment RDST
276	7-G	300	Increment RDST
277	7-I	300	Fetch destination address
300	7-J	217	Fetch destination operand
301	7-L	302	Increment PC
302	7-M	300	Determine destination address
303	7-O	304	Increment PC
304	7-P	305	Determine address of destination address
305	7-Q	300	Fetch destination address
306	8-E	265	Increment RDST
307	8-G	311	Increment RDST
310	8-I	311	Fetch destination address
311	8-J	265	Fetch destination operand
312	8-L	313	Increment PC
313	8-M	311	Determine desination address
314	8-O	315	Increment PC
315	8-P	316	Determine address of desination address
316	8-Q	311	Fetch destination address
317	9-E	320	Increment RDST
320	9-F	000	Jump address to PC
321	9-H	320	Fetch jump address
322	9-J	323	Increment PC
323	9-K	000	Determine jump address
324	9-M	325	Increment PC
325	9-N	326	Determine address of jump address
326	9-O	320	Fetch jump address
327	10-E	336	Increment RDST
330	10-G	336	Fetch jump address
331	10-I	332	Increment PC
332	10-J	336	Determine jump address
333	10-L	334	Increment PC
334	10-M	335	Determine address of jump address
335	10-N	336	Fetch jump address
336	10-O	337	Decrement SP
337	10-P	340	Set up bus address
3401	10-Q	341	Output RSRC to stack
341	10-R	342	Move PC to RSRC
342	10-S	000	BREG to PC
343	11-B	000	Load condition codes
344	11-F	355	Increment RDST
345	11-H	354	Increment RDST
346	11-J	354	Fetch destination address
347	11-L	350	Increment PC
350	11-M	354	Determine destination address
351	11-O	352	Increment PC
352	11-P	353	Determine address of destination address
353	11-Q	354	Fetch destination address
354	11-R	355	Fetch swapped destination operand
355	11-S	000	Store data, load condition codes
356	12-B	050	Shift operand
3572	12-F	370	Increment RDST
360	12-H	362	Increment RDST
361	12-J	362	Fetch destination address
362	12-K	370	Fetch destination operand
363	12-M	364	Increment PC
364	12-N	362	Determine destination address
365	12-P	366	Increment PC
366	12-Q	367	Determine address of destination address
367	12-R	362	Fetch destination address
370	12-S	217	Shift operand
371	13-F	463	Increment RDST
372	13-H	455	Increment RDST
373	13-J	455	Fetch destination address
374	13-L	375	Increment PC
375	13-M	455	Determine destination address
376	13-O	377	Increment PC
377	13-P	643	Determine address of destination address
400	18-S	402,502	Complement & test sign of multiplicand
401	18-T	404,406	Test divisor for zero
402	19-A	403,503	Zero R17 and B, test multiplicand
403	19-J	606	Put multiplier in BX
404	21-A	612	Put one's complement of divisor in R13
405	19-D	407	Put one's complement of multiplier in R13
406	22-W	620	Set V bit
407	19-U	413,417,433,437, 453,457,473,477	Shift right (partial product, multiplier), decrement counter
410	20-C	420,422	Test upper product for all 1's
411	20-L	611	Clear C bit
412	20-H	414,416	Test lower product for zero
413	19-M	413,417,433,437, 453,457,473,477	Shift right (partial product, multiplier), decrement counter
414	20-J	411,511	Test MSB of lower product
415	20-G	611	Set C bit
416	20-I	414	Set Z bit
417	19-P	607	Store upper product
420	20-E	415	Set V bit
421	21-L	424	Fetch lower dividend
422	20-D	415,515	Test MSB of lower product
423	21-F	424	Take one's complement of upper dividend
424	21-M	425,435	Shift upper dividend left, test sign of divisor
425	21-O	440,442	Subtract divisor from dividend, test remainder
426	22-S	616	Set V bit
427	19-L	407	Subtract multiplicand from partial product
430	25-A	452,456	Test counter for 0, fetch upper part of operand
431	22-J	616	Clear V bit
432	26-N	731	Move PC to R5
433	19-T	473	Add multiplicand to partial product
434	24-A	516,517	Test IR9 to determine ASH/ASHC
435	21-N	440,442	Subtract divisor from dividend, test remainder
436	17-D	556	BREG to SP
437	19-Q	607	Store upper product
440	21-P	442,462	Test first quotient bit
441	22-B	461	Add divisor to remainder
442	21-G	640,650,660,670	Shift remainder left, test sign of divisor, test LSB of quotient
443	22-N	615	Srore remainder
444	22-D	614	Srore remainder
445	24-E	635	Save BX in B, clear N bit
446	22-A	441,451,461,471	Test quotient LSB and sign of divisor
447	24-D	634	Save BX in B, clear N bit
4503	17-II	744	Step SP
451	22-K	471	Add divisor to remainder
452	25-D	652,653	Test IR9 to determine ASH/ASHC, fetch lower part of operand
453	19-O	413	Subtract multiplicand from partial product
454	24-K	641	Clear C bit
455	13-R	463	Fetch destination data, enable previous mode
456	25-B	500,501	Test IR9 to determine ASH/ASHC
457	19-R	607	Store upper product
460	26-B	470	Move PSW to B
461	22-C	444,544	Test sign of dividend
462	22-Y	000	Set V bit
463	13-S	472	Decrement SP
464	24-U	465	Store lower result, clear N bit
465	24-X	637	Clear Z bit
466	24-T	465,467	Store lower result, clear N bit, test for 0
467	24-W	637	Clear Z bit
470	26-C	504	Increment vector address
471	22-L	443,543	Test sign of dividend
472	13-P	217	Set up bus address
473	19-N	413,417,433,437, 453,457,473,477	Shift right (partial product, multiplier), decrement counter
474	14-G	513	Increment RDST
475	14-J	513	Fetch destination address
476	14-L	552	Increment PC
477	19-S	607	Store upper product
500	25-C	512	Clear BX to indicate C bit = 0
501	25-M	651	No operation
502	19-I	403	Zero R17 and B
503	19-B	405,505	Put multiplier in R12 and test sign
504	26-D	560	Fetch new PSW
505	19-C	603	Put one's complement of multiplier in R13
506	14-D	510	Increment PC
507	19-F	604	Shift right (100000, 100000)
510	14-P	514	Determine address of destination address
511	20-K	611	Set C bit
512	24-C	445,447,545	Store upper result, test sign of Z bit
513	14-R	520	Setup bus address, enable previous mode
514	14-Q	513	Fetch destination address
515	20-F	611	Clear C bit
516	24-B	512,516	Shift upper part of operand
517	24-O	707	Fetch lower part of operand
520	14-S	000	Output data to destination address
521	21-C	613	Fetch lower dividend
522	17-J	523	Shift BREG left one bit
523	17-K	000	Add offset to PC
524	22-V	000	Set V bit
525	17-M	527	Fetch top of stack
526	22-R	616	Clear V bit
527	17-N	533	Step stack to pointer
530	22-G	431,531	Clear U bit
531	22-I	616	Set V bit
532	22-H	431	Clear N bit, set Z bit
533	17-O	000	Load stack data into destination register
534	22-Q	426,526	Clear V bit
535	17-GG	537	Step SP
536	22-P	526	Clear N bit, set Z bit
537	17-HH	450	Fetch top of stack
540	26-KK	741	Clear IR to halt processor
541	17-S	000	Mask and set condition codes
542	17-Y	000	Mask and set condition codes
543	22-M	614	Srore remainder
544	22-E	615	Srore remainder
545	24-F	635	Save BX in B, set N bit
546	17-CC	547	Calculate offset
547	17-DD	000	Subtract offset from PC
550	24-M	641	Clear C bit
551	17-G	561	Data to R5
552	14-M	513	Determine destination address
553	17-B	555	Shift BREG left, R5 to BXREG
554	24-L	641	Set C bit
555	17-C	436	Add PC to BREG
556	17-E	557	BXREG to PC
557	17-F	551	Fetch top of stack
560	26-E	562	R6 <- R6-2, enable stack overflow
561	17-H	000	Step SP
562	26-F	566	Place SP address on bus lines
563	18-E	602	Increment RDST
564	24-V	465	Store lower result, set N bit
565	18-G	601	Increment RDST
566	26-G	570	Output old PSW, enable double bus errors
567	18-I	601	Fetch destination address
570	26-H	572	Decrement SP, enable stack overflow
571	18-K	574	Increment PC
572	26-I	573	Place SP address on bus lines
573	26-J	577	Push old PC on stack
574	18-L	601	Determine destination address
575	18-N	576	Increment PC
576	18-O	600	Determine address of destination address
577	26-K	646	Decrement vector address
600	18-P	601	Fetch destination address
601	18-Q	602	Fetch multiplicand/divisor
602	18-R	400,401	Load step counter, test IR9 for multiply/divide
603	19-E	407,507	Test two's complement of multiplier
604	19-G	605	Load B and R5 with 040000
605	19-H	610	Zero lower product
606	19-K	407,427	Test LSB of BX for first multiply step
607	20-A	610	Store lower product
610	20-B	701	C out is the sign of the product
611	20-M	000	Transfer condition codes to PSW
612	21-B	421,521	Fetch upper dividend and test sign
613	21-D	423,623	Take two's complement of lower dividend
614	22-F	530,532	Store quotient, clear N bit
615	22-O	534,536	Store quotient, set N bit
616	22-T	617	Clear C bit
617	22-U	000	Transfer condition codes to PSW
620	22-X	000	Set C bit
621	23-E	633	Increment RDST
622	23-G	632	Increment RDST
623	21-E	424,524	Take two's complement of upper dividend
624	23-I	632	Fetch destination address
625	23-K	626	Increment PC
626	23-L	632	Determine destination address
627	23-N	630	Increment PC
630	23-O	631	Determine address of destination address
631	23-P	632	Fetch destination address
632	23-Q	633	Fetch shift count
633	23-R	430,434	Test sign of counter
634	24-G	636	Set Z bit
635	24-H	636	Clear Z bit
636	24-I	454,554	V bit <- OVX
637	24-J	550,554	V bit <- OVX
640	21-J	442,446	Add divisor to remainder, test counter sign
641	24-N	000	Transfer condition codes to PSW
642	14-E	25x	Increment SP
643	13-Q	455	Fetch destination address
644	14-T	642	Move stack data to R12
645	17-FF	535	Data to PC
6464	26-L	320	Fetch new PC
647	26-CC	654	Add 2 to R15
650	21-K	442,446	Add divisor to remainder, test counter sign
651	25-N	464,466,564	Store upper result, test sign of Z bit
652	25-H	753	Clear BX so that 0's shift into B
653	25-E	653,657	Shift double operand left, decrement counter
654	26-DD	656	Set R15 to 5
655	25-K	512	Clear BX to indicate C bit is 0
656	26-EE	201	Set R15 to 013
657	25-F	651,751	Test R17 to determine C bit
660	21-H	442,446	Subtract divisor from remainder, test counter sign
661	5-O	261	Increment PC
662	6-M	271	Increment PC
663	15-I	675	Increment RDST
664	15-K	666	Increment RDST
665	15-N	666	Fetch destination address
666	15-L	675	Fetch destination operand
667	15-P	671	Increment PC
670	21-I	442,446	Subtract divisor from remainder, test counter sign
671	15-Q	666	Determine destination address
672	15-S	673	Increment PC
673	15-T	674	Determine address of destination address
674	15-U	666	Fetch destination address
675	15-B	676	Set R17 to all 1's
676	15-C	677	Set R17 equal to PSW address
677	15-D	704	Place PSW address on bus address lines
700	17-BB	546	Swap bytes, shift BREG left
701	20-N	410,412	Test upper product for zero
702	17-AA	000	No operation
703	24-R	723	Clear counter to indicate C bit is 0
704	15-E	000	Output destination operand to PSW
705	16-B	000	Move R12 to RDST
706	16-D	217	Move PSW data to R12
707	24-Q	703,707,723,727	Shift double operand right, increment counter
710	16-H	717	Increment RDST
711	16-K	717	Fetch destination address
712	16-M	713	Increment PC
713	16-N	717	Determine destination address
714	16-P	715	Increment PC
715	16-Q	716	Determine address of destination address
716	16-R	717	Fetch destination address
717	16-I	706	Place destination address on bus address lines
720	26-HH	741	Clear IR to halt processor
721	26-Z	737	Shift B left, zero B LSB
722	26-Q	734	Put all 1's in the PC
723	24-S	464,466,564	Store upper result, test sign of Z bit
724	26-S	735	Move all 1's to B
725	26-AA	540,740	Increment PC, branch on COUT
726	26-II	741	Clear IR to halt processor
727	24-P	703,707,723,727	Shift double operand right, increment counter
730	26-JJ	741	Clear IR to halt processor
731	26-O	733	Clear PC
732	26-U	736	Move 016 to counter
733	26-P	720,722	Test for 0 PC
734	26-R	724,726	Test for 0 PC
735	26-T	730,732	XOR PC and B
736	26-V	743	Clear B
737	26-X	742	Move B to BX
740	26-BB	647	Clear R15
741	26-LL	000	No operation
742	26-Y	721,725	Add PC and BX, decrement count
743	26-W	737	Put 1 in B
744	17-JJ	000	Data to PSW
745
746
747
750
751	25-G	651	Set counter to indicate C bit is 1
752
753	25-I	753,757	Shift single operand left, decrement counter
754
755	25-L	512	Set BX to indicate C bit is 1
756
757	25-J	655,755	Test R17 to determine C bit

Notes:

1 - prints say 346; '6' written for '0'
2 - prints say 375; digit swap
3 - prints say 540; digit swap
4 - prints give a different 'next' from a microcode dump

+ - This is the main instruction decode multi-way branch. Possible next microinstructions include:

• 11x (indirect to 05x, 07x, 06x)
• 04x, 16x, 02x, 15x, 03x, 17x, 10x, 25x, 12x, 13x, 22x, 23x (instructions)
• 003, 004, 006, 007, 011, 014, 020, 150, 200, 260 (individual instructions)
• 270, 210, 240, 140 (simple instructions)

External links

• 11/34 Vol 2. Field Maintenance Print Set (MP00082) - contains microcode Flow Diagrams (on pp. 15-40 of the PDF)
• Dump of KD11-EA microcode on BitSavers (in symbolic form)