223:+-+-+-+------+-+--------------+ |0|X|P|Opcode|I| Address | +-+-+-+------+-+--------------+ 1 2 bit 0 1 2 3 8 9 0 3 Bits 0-2 are called the "tag" Bit 0 is always zero. Bit 1 '1'b indicates that the operand address is to be indexed. Bit 2 '1'b indicates that this instruction is a programmed operator (POP). Bits 3-8 is the instruction code or programmed-operator id. Bit 9 '1'b indicates that the operand address shall be indirected (indexing preceding indirecting), potentially recursively. Bits 10-23 Contain the operand address.
314:
programmed operator. In this case a '1'b in bit position 0 indicates that this is a "system POP", or "SYSPOP", instead of a standard programmed operator. In user mode bit positions 10–12 "constitute a virtual memory block number", that is specify a memory map register, and bits 13–23 "specify a location within the virtual memory block." The contents of the memory map register are prepended to instruction bits 13–23 to form the effective address.
480:
second and 1,400 bits per inch. The 9448 Tape
Control Unit connects the tape drive unit to any Series 900 system. The tape cartridge contains approximately 600 feet of Mylar tape with two independent tracks each holding approximately 1.5 million IBM characters (6 bits plus parity) yielding a capacity of approximately 4 million six bit characters per cartridge.
278:+-+-+-+------+-+--+----------+ |0|X|P|Opcode|I|EM| Address | +-+-+-+------+-+--+----------+ bit 0 1 2 3 3 9 11 1 2 01 2 3 Bits 10 and 11 specify either no extended memory (EM='00'b—references first 8K words of memory) or prepend the contents of EM2 (EM='10'b) or EM3 (EM='11'b) to form the effective address.
20:
520:
The monitor routine accepts control information which, among other things, may include a request to load and execute a specified standard system routine. The monitor performs its functions between jobs and does not exercise control over the execution of a program once that program has been loaded and
160:
Double precision floating point +-+-----------------------+ |±| Fraction | high-order word +-+-----------+-+---------+ | frac(cont) |±|exponent | low-order word +-------------+-+---------+ bit 0 1 2 5 3 High-order word:
479:
9446 tape drive subsystem and associated 9401 tape cartridge was developed by SDS for the SDS 900 series and announced in May 1964 Each tape drive unit consists of two independently controlled magnetic tape drives mounted on a standard 10½-inch by 19-inch panel. Data are recorded at 7.5 inches per
164:
Single precision floating point +-+-----------------------+ |±| Fraction | high-order word +-+-----------+-+---------+ | not used |±|exponent | low-order word +-------------+-+---------+ bit 0 1 2 5 3 The format is
197:
bit is set, an instruction code of xx is treated as a call to location 1xx (octal). The location of the POP instruction is saved in location zero. Bit zero of location zero is set to the current value of the overflow indicator and the indicator is reset. Bit 9 of location zero is set to '1'b to
141:
is implemented in software using "programmed operators", except on the SDS 9300 which has hardware floating point. All floating point numbers are stored as 48-bit double words. Single precision has a 24-bit signed fraction and a 9-bit signed exponent, double precision has a 39-bit fraction and a
313:
SDS 940 user mode instruction format: +-+-+-+------+-+---+---------+ |U|X|P|Opcode|I|Blk| Address | +-+-+-+------+-+---+---------+ bit 0 1 2 3 3 9 1 1 2 0 3 3 Bit 0 is ignored in user mode unless bit position 2 (P) indicates that this is a
252:
The 930 offers a "memory extension system" that allows addressing more than 16284 words. Two 3-bit "Extend Memory
Registers", called EM2 and EM3, are provided which can be loaded with a value to be used as the high-order three bits of the effective address. Addresses
118:
Maximum address space is 2 or 16,384 words (16 KW—64 K char) on the 910 and 920. The 9300 and 930 support up to 32K (128 K char), and the 940 and 945 support up to 64K (256 K char), although the method for accessing the memory above 16K differs.
261:(the first 8192 words of memory) are always unmodified. If the high-order octal digit of the address in the instruction is two the contents of EM2 replaces the high-order digit in the effective address; when the digit is three the contents of EM3 are used.
181:. The word at the effective indirect address is decoded as if it were an instruction (except that the instruction code is ignored), allowing an indirect address to also specify indirection or indexing. Multiple levels of indirect addressing are allowed.
234:
Main memory on the 920 is 4096 to 16384 words of magnetic core memory. The fixed-point add time is the same as the 910 (16 μs), but the fixed-point multiply is roughly twice as fast at 128 μs. The 920 can have up to 1024 priority interrupts.
110:
single address machines. Programmer-accessible registers are A (accumulator), B (extension), X (index), and P (program counter—14 bits), plus an overflow indicator. The 9300 has three index registers X1 through X3 which can be used as
264:
To retain compatibility with earlier models. when the computer is started the value in EM2 is set to 2 and EM3 to 3, allowing programs to address the first 16384 words of memory. These registers can be loaded by the program.
271:
930 memory has a cycle time of 1.75 μs. A fixed-point add takes 3.5 μs, and a fixed-point multiply 7.0 μs. The priority interrupt system allows 2–38 input/output interrupts and up to 896 system interrupts.
142:
9-bit exponent. Both the exponent and the fraction are stored in big-endian twos-complement format. The binary point is assumed to be immediately left of the high-order bit of the fraction. The value of the number is
451:, used to call monitor services. When a SYSPOP is encountered in user mode (instruction bits 0 and 2 are '1'b), the computer first enters monitor mode and then accesses the vector of instructions at
337:
For programs running in user mode, the high-order three bits of the address field of an instruction serve as an index to an array of eight registers (R0-R7). Each register contains a 5-bit value (
193:
facility allows the instruction code field to indicate a call to a vector of subroutine addresses. The six bit instruction code allows up to 64 programmed operators (octal 00 through 77). If the
435:
The monitor can use either the monitor memory map or the user memory map, determined by the value of bit 0 of the instruction. This allows the monitor access to the user's address space.
91:
The 910 and 920 were first shipped in August, 1962. The 9300 was announced in June, 1963. The 925 and 930 were announced in 1964. The 940 was announced in 1965, and the 945 in 1968.
161:
bit 0 fraction sign bits 1-23 high-order part of fraction Low-order word: bits 0-14 low-order part of fraction bit 15 exponent sign bits 16-23 exponent
307:
A set of memory map registers is used to map virtual addresses to physical. There are eight memory map registers, each mapping 2K words, to provide an address space of 16K.
268:
The program loader uses the high-order bit of the instruction, ignored by all models, as a flag indicating that the instruction currently being loaded is to be relocated.
344:) which is prepended to the low-order 11 bits of the instruction address field to form the 16-bit physical address. This divides virtual memory logically into eight
467:
The 945 is an upgrade of the 940 time-sharing system. It was advertised as being able to "support up to 24 simultaneous users and up to 64 authorized users."
525:
That portion of the monitor which remains in core memory during program execution consists of the
Monitor Bootstrap Routine and the Unit Assignment Table.
198:
indicate an indirect address, allowing the programmed operator routine to indirectly access the data specified in the address of the POP instruction.
820:
847:
348:
of 2048 words each. The registers allow access to 16K words at any one time out of a possible 32K words of physical memory. A sixth bit (
213:
with a cycle time of 8 μs. A fixed-point add instruction takes 16 μs, a fixed-point multiply takes 248 μs. Two hardware
801:
921:
916:
901:
896:
891:
886:
876:
726:
310:
The instruction format for normal mode is the same as for the 930. Addressing differs between user mode and monitor mode.
275:
The instruction format for the 930 system is compatible with prior systems except for the bits used for extended memory:
585:
Physically the memory map is contained in two 24-bit registers RL1 and RL2, each of which is set and cleared as a unit.
881:
497:
443:
In user mode, programmed operators function the same as normal mode, accessing the user's virtual locations 100-177
661:
931:
632:
512:, since application programs have control of all the resources of the computer when running. Instead it is a
292:
The 940 adds modes of operation to support multiple users. The operating mode of previous models is renamed
757:
79:
43:
926:
206:
402:, contain the read-only values 0–5, providing direct access to physical addresses 0–8K-1 (00000–17777
210:
414:
is used to form the physical address as it is in normal mode. For addresses 12K–16K-1 (30000–37777
128:
39:
543:
85:
493:
370:
115:
to allow access to memory above 16K words. The W and Y registers are used for input/output.
95:
610:
707:
688:
501:
178:
174:
112:
323:
138:
910:
576:
The use of memory map registers was carried forward to the 32-bit Sigma computers.
549:
132:
488:
The primary operating system for the line, excluding the 940 and 945, is the
214:
165:
the same as double precision except that only 24 bits of fraction are used.
516:, providing job-to-job transition and supporting services to applications.
557:
27:
758:"Technical Manual - MAGPAK SERIAL MAGNETIC TAPE SYSTEM MODELS 9446/9448"
287:
247:
66:
60:
23:
300:
limits access to input/output and certain privileged instructions. A
529:
Other standard system routines that are included in the monitor are:
107:
714:. A Fourth Survey of Domestic Electronic Digital Computing Systems.
695:. A Fourth Survey of Domestic Electronic Digital Computing Systems.
19:
220:
The instruction format for the 910 and 920 systems is as follows:
18:
786:"SDS MAGPAK TAKES THE GRIEF OUT OF SMALL COMPUTER OPERATION".
369:=1 indicates an unassigned block, and any reference causes a
355:) in each register indicates a read-only block of storage.
376:
The memory map for monitor mode is similar. There are no
322:
The 940 accesses memory through a memory map to provide
849:
MONARCH Reference Manual for 900 Series/9300 Computers
373:. The map registers can only be set in monitor mode.
226:
The SDS 910 weighed about 900 pounds (410 kg).
16:
Backward compatible line of transistorized computers
406:). For addresses in the range 8K–12K-1 (20000–27777
238:The 920 weighed about 1,000 pounds (450 kg).
78:is an extension of the 9xx architecture. The 1965
822:SDS Monarch Reference Manual 900 Series Computers
611:"The COMPUTER That Will Not Die: The SDS SIGMA 7"
500:, later versions can reside on a head-per-track
46:in the 1960s and 1970s. This line includes the
518:
447:. The 940 also includes a facility to execute
326:. The map formats differ slightly between a
84:is an incompatible 12-bit system built using
42:line of transistorized computers produced by
8:
508:(Rapid Access Data) File. MONARCH is not an
492:operating system. MONARCH is a single-task
304:is used to run users' application programs.
752:
750:
748:
217:are standard with up to 896 more optional.
521:the monitor has transferred control to it.
604:
602:
496:operating system. Originally resident on
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654:
598:
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418:) the contents of memory map registers
449:System Programmed operators (SYSPOPS)
209:on the 910 is 2048 to 16384 words of
7:
846:Scientific Data Systems (Dec 1969).
819:Scientific Data Systems (Nov 1964).
177:, if specified, is performed before
725:Xerox Data Systems (October 1969).
14:
728:Reference Manual XDS 940 Computer
631:American Nuclear Society (1965).
539:Standard input/output subroutines
94:The 9 series was replaced by the
157:The floating point formats are:
662:"Eight Years Ago: May 29, 1968"
432:are used to form the address.
86:monolithic integrated circuits
1:
902:Reference manual for SDS 9300
127:Fixed point data is 24-bits,
897:Reference manual for SDS 940
892:Reference manual for SDS 930
887:Reference manual for SDS 925
882:Reference manual for SDS 920
877:Reference manual for SDS 910
706:Weik, Martin H. (Jan 1964).
687:Weik, Martin H. (Jan 1964).
410:) memory extension register
439:System programmed operators
948:
536:The MONARCH update routine
285:
245:
790:. May 1964. pp. 2–3.
922:Transistorized computers
560:compiler was available.
173:For address generation,
917:Scientific Data Systems
802:"SDS 900 SERIES MAGPAK"
44:Scientific Data Systems
527:
31:
22:
391:equivalents, called
211:magnetic-core memory
185:Programmed operators
150:is the fraction and
767:. SDS. October 1965
191:programmed operator
102:General description
40:backward compatible
533:The MONARCH Loader
455:(physical) 100-177
332:monitor memory map
169:Address generation
32:
154:is the exponent.
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932:24-bit computers
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510:executive system
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129:two's complement
106:All systems are
96:SDS Sigma series
38:computers are a
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871:External links
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668:. May 31, 1976
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633:"<none>"
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666:Computerworld
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639:. Vol. 8
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502:magnetic disk
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927:Time-sharing
856:. Retrieved
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829:. Retrieved
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769:. Retrieved
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735:. Retrieved
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670:. Retrieved
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641:. Retrieved
637:Nuclear News
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614:. Retrieved
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36:SDS 9 Series
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806:archive.org
556:By 1969 an
544:Meta-Symbol
294:normal mode
207:Main memory
179:indirection
911:Categories
788:Datamation
593:References
550:FORTRAN II
380:bits; the
318:Memory map
215:interrupts
133:big-endian
70:, and the
771:March 17,
765:Bitsavers
708:"SDS 920"
689:"SDS 910"
546:assembler
504:called a
302:user mode
296:. A new
558:ALGOL 60
552:compiler
484:Software
175:indexing
146:, where
76:SDS 9300
28:Swissair
858:Dec 30,
831:Dec 27,
737:Nov 12,
672:Nov 10,
643:Nov 10,
514:monitor
490:MONARCH
463:SDS 945
362:=0 and
288:SDS 940
282:SDS 940
248:SDS 930
242:SDS 930
230:SDS 920
202:SDS 910
72:SDS 945
67:SDS 940
61:SDS 930
56:SDS 925
52:SDS 920
48:SDS 910
24:SDS 930
616:Nov 7,
477:MAGPAK
471:MAGPAK
346:blocks
330:and a
257:–17777
108:24-bit
81:SDS 92
74:. The
30:, 1966
853:(PDF)
826:(PDF)
761:(PDF)
732:(PDF)
564:Notes
494:batch
253:00000
860:2015
833:2015
773:2019
739:2015
674:2015
645:2015
618:2015
542:The
475:The
425:and
371:trap
189:The
34:The
523:...
506:RAD
412:EM2
144:F*2
26:at
913::
804:.
763:.
747:^
710:.
691:.
664:.
653:^
635:.
601:^
459:.
397:–M
386:–R
334:.
135:.
131:,
98:.
88:.
64:,
58:,
54:,
50:,
862:.
835:.
775:.
741:.
676:.
647:.
620:.
457:8
445:8
429:7
427:M
422:6
420:M
416:8
408:8
404:8
399:5
395:0
393:M
388:5
384:0
382:R
378:P
366:n
364:P
359:n
357:R
352:n
350:P
341:n
339:R
259:8
255:8
195:P
152:E
148:F
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