Archive for the 'CPU of the Day' Category

March 15th, 2018 ~ by admin

CPU of the Day: Intel Jayhawk – The Bird that Never Was

Intel Jayhawk Thermal Sample – 80548KZ000000 QBGC TV ES – Made in April 2004 Just 3 weeks before it was canceled

Perhaps fittingly the Jayhawk is not a bird, but rather a term used for guerilla fighters in Kansas during the American Civil War.   It is also the name of a small town in California 150 miles Northeast of Intel’s headquarters in Santa Clara.  It was also the chosen code name for a Processor Intel was working on back in 2003.  In 2003 Intel was working on the Pentium 4 Prescott processor, to be released in 2004 and its Xeon sibling, the Nocona (and related Irwindale),  The Prescott was a 31 stage design made on a 90nm process.  There was hopes it would hit 4+ GHz but in production it never did, though overclockers, with the help of LN2 cooling were able to achieve around 8GHz.  Increasing the length of the pipeline helps allow higher clock speeds, the Northwood core had a 20-stage pipeline so the Prescott was a rather big change.  There is a cost of lengthening the pipe, processors don’t always execute instructions in order, often guessing what will come next to speed up execution.  This is called speculative execution, processors also guess what data is to be needed next, and stick it in cache.  If either of these ‘guesses’ is wrong, the processor needs to flush the pipeline and start over, at a comparatively massive hit in performance.  This is what performance doesn’t always scale very linearly with clock speed.

Intel figured that this wouldn’t be an issue and so the Prescotts successor was to have a 40-50 stage pipeline.   THe hopes were for 5GHz at 90nm and 10GHz at 65nm. The desktop version was known as Tejas, and the server version, Jayhawk.  Initially these were to be made on the 90nm process, same as Prescott, before being transitioned to a 65nm process.  It increased the L1 cache to 24k (some sources say 32k) from the Prescotts 16k.  The Instruction trace cache was still 16k micro-ops, though this could have been increased.  L2 cache would have been 1MB at introduction and 2MB once the processor moved to a 65nm process.  Eight new instructions were to be added called ‘Tejas New Instructions’ or TNI, these later would become part of the SSSE3 instructions released with the Core 2 processor.  It also would bring ‘Azalia’ Intel’s High definition audio codec, DDR2 support, a 1066MHz bus, and PCI-Express support.  It turns out there was a problem….

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January 28th, 2018 ~ by admin

CPU of the Day: Tandem CLX 800 – It Takes 2 To Tango

TANDEM CLX 800 Processor – VLSI CMOS 1u process – 16MHz.

Tandem Computers was established way back in 1974, and was one of the first (if not the first) dedicated fault-tolerant computing companies.  They designed completely custom computers designed for use in high reliability transaction processing environments.  These were used for support of stock exchanges, banks, ATM networks, telephone/communications interchanges, and other areas where a computer failure would result in significant, costly, disruptions to business services.  Tandem was started by James Treybig, formally of HP, and a team he lured away from HP’s 3000 computer line.

Tandem computers are designed to do two things well, fail-over quickly when a failed part is detected.  This means that if a faulty processor or memory element is found, it can be automatically disabled, and processing continues, uninterrupted, on the rest of the system.  The other design element that Tandem perfected was allowing the computer to find and isolate intermittent problems.  If a processor or storage element ceases to work, that is relatively easy to figure out, but if a processor is glitchy, causing errors only occasionally, that can be much harder to find and can result in serious problems for the user.  This is known as ‘Fast Fail’ and today is a pretty standard concept, find the error, catch it, and prevent erroneous data from ever making it back into the database.  Tandem computers were designed from the ground up to be fault tolerant, disks were mirrors, power supplies, busses,

Tandem CLX 600 PCB (click for larger)

processors,all were redundant, but unlike some other systems, components were not kept as ‘hot spares’ sitting idle until something failed.  This kept hardware from being ‘wasted.’ Under normal operation if it was in the system, it was contributing to system performance.  A failed component then would reduce system performance until it was replaced/fixed, but a customer would not be paying for hardware that served them no purpose unless something broke.

To support these goals Tandem designed their own processors and instruction set architecture know as TNS (Tandem NonStop).  The first processors were a 16-bit design call the T/16 (later branded NonStop I) made out of TTL and SRAM chips spanning 2 PCBs.  Performance was around 0.7MIPS in 1976.  They were a stack based design similar to the HP3000 with added registers as well.  T/16 systems supported 2-16 processors. NonStop II, released in 1981, was similar, but supported the occasional 32-bit addressing, increasing accessible memory form 1 to 2MB per CPU and performance to 0.8MIPS.

The 1983 introduction of TXP saw a great performance improvement, up to 2.0 MIPS, but kept the same form factor.  The processor was implemented in TTL, with the addition of many PALs and added much better support for 32-bit addressing.  In 1986 the NonStop VLX was released, which moved to an ECL based processor.  This was a full 32-bit design, running at 12MHz (3MIPS) but still using discrete components and a new bus system as well.  This was to be the high end of the NonStop line, it was fast reliable, and rather large.  The desire for a more economical system to fit the needs of smaller customers led to a first for Tandem…

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December 19th, 2017 ~ by admin

Chip of the Day: TRW MPY-16AJ – Making Multiplication Manageable

TRW MPY16AJ – 1978

In Primary School students are tasked with memorizing their multiplication tables.  Taking the time to manually calculate 6×5 is much slower than simply committing the result to memory.  This allows more complex math to be processed quicker as the students skills develop.  Typically this is limited to numbers up to 12×12, resulting in 144 results to ‘store.’  In computing the same can be done.  A ROM can be used as a lookup table for multiplication.  The problem is it does not scale well.  Handling 4×4-bit multiplication requires a 256×8 ROM (2m+n addresses and m+n outputs). This could be handled by a many ROMs available in the 1970’s.  Anything more than 4-bits though was simply not possible.  This gave rise to the need for multipliers to calculate the result.

TRW MPY16AJ – Large Heatsink affixed to package to dissipate its 5W

This was a problem TRW set out to rectify in 1976.  TRW LSI Products was formed in the 1960’s to commercialize the transistor products that had been developed by Pacific Semiconductors, a division of TRW.  It was James Buie who invented the TTL logic gate in 1961 while working for TRW.  TTL went on to become the logic standard throughout the 1970’s and 80’s.   TRW was involved in aerospace, helping design planes, satellites, and missiles, fields that required processing of signals data, what became known as Digital Signal Processing (DSP).  In the 1980’s processors were designed to handle this, such as the TI TMS320 series, but in the 1970’s it had to be done with discrete components.  DSP systems had several needed blocks, Fast ADCs, ALUs, and multipliers.  TRW invented fast ADCs to handle the inputs, and ALUs were available such as AMDs Am2901 or even the TTL series 74181s.  Multipliers however were not widely available, especially for large bit-widths.

MPY-16 die

TRW’s first multiplier was a custom device to work with their own avionics processing system.  It was made on a Bipolar process, and multiplexed the entire product, using around 40 pins total (the entire product was multiplexed with the operands).  It could handle a multiply in 330ns worst case.  Interestingly yields of the device were considered ‘excellent’ at 3 working devices per wafer (out of 19 per wafer (most likely a 2″ wafer)).  Today, yields like that would be completely unacceptable.

TRW designed the MPY-16AJ as a brute-force 16×16 multiplier.  It was designed on a Bipolar process with around 3600 gates.  It implements a series of AND gates and CARRY-SAVE-ADDERS to implement the multiplication.  There are faster methods, but they come at the cost of complexity and power draw.  As designed the the MPY-16AJ dissipates 5 Watts while handling a signed (2’s complement) multiplication in a worse case 230ns).  They MPY16 was packaged in a large 64-pin package to limit the # of pins that had to be multiplexed.  The lower 16-bits of the product are multiplexed with one of the operands.  This is acceptable as in many applications the upper 16-bits of the product are sufficient accuracy.  The 64-pin package allowed for not less multiplexing, but also a much larger surface for heat dissipation.  A heatsink was also affixed to the package as well.

Micron (Russia) 1802VR5 – MPY16HJ Clone made in 1992

Later versions of the MPY-16 added support for unsigned multiplication as well (the MPY16H) and became the standard for 16-bit multipliers.  Compatible multipliers were made by Analog Devices (ADSP1016, 40-50ns at 150mW) and LOGIC LMU16/216) in CMOS, by Weitek (WTL1516/A/B, 50-100ns at 0.9-1.8W) in NMOS, by Synertek (SY66016 100ns at 1.5W) in HMOS, by AMD (Am29516 38ns at 4W) in ECL, as well as many others.  These were implemented internally with different processes, and different multiplier algorithms but externally they all mimicked the standard TRW MPY16J and served as the basis of many signal processing and high end math computers.  As a testament to their usefulness, the MPY16 was also copied by the USSR as the 1802VR5.  The TRW MPY16 was last made in the mid-1980’s but its clones continued to be made into the 1990’s.  Today its functions can be handled by any DSP, CPU or even coded into a FPGA, but for a time, the MPY16 multiplied the efficiency of many processing systems.

December 7th, 2017 ~ by admin

CPU of the Day: Hitachi HD6801S0PJ – Automotive 6801

Hitachi HD6801S0PJ – 1982 Automotive Spec 6801

The original Motorola MC6801 was released in 1977, built on a 5.1u NMOS process with 35,000 transistors (some sources say 25,000, which may be the ‘active’ transistor sites).  One of the very first customers was General Motors, you can read more about that in last years article on the 6801.  Hitachi was the primary second source for Motorola, primarily to supply the Japanese market, but they also competed with Motorola in the US market as well.  Hitachi released their version of the 6801 in 1980, with full production commencing in 1981.  It was made on a 3-micron NMOS process and was available in both a 1MHz speed (HD6801S0) and 1.25MHz (HD6801S5).  Around this time (1982) Hitachi was also transitioning their part numbering system.  Originally these parts were HD468xx… which was a bit confusing so they dropped the ‘4’.  For several years in the early 1980’s it is not uncommon to find parts with either, or both part numbers on them.

The pictured Hitachi HD6801S0P in interesting for a couple reasons.  The A00 denoted the ROM code for the 2K of onboard ROM.  A00 means that it is unprogrammed.  This would be useful for testing the 6801 with an external EPROM etc.  The ‘J’ on the package denotes that this device is a industrial/automotive spec part with an increased temperature range, in this case -40-85C.  Hitachi date codes are different from other manufacturers but are relatively simple.  The code 2E1 denotes the first week (1) of May (E) in 1982 (2).

Hitachi marked with both old and new part numbers
HD46800DP and HD6800P – dated 3F1 – First week of June 1983

Year* Month** Week
8 – 1978 A – January 1 – Week 1
9 – 1979 B – February 2 – Week 2
0 – 1980 C – March 3 – Week 3
1 – 1981 D – April 4 – Week 4
2 -1982 E – May 5 – Week 5
3 – 1983 F – June
4 – 1984 G – July
5 – 1985 H – August
6 – 1986 J – September
7 – 1987 K – October
8 – 1988 L – November
9 – 1989 M – December

*Years repeat, so 0 is used from 1980 and 1990
** ‘I’ is skipped to avoid confusion with the number ‘1’

What is perhaps more interesting is what came with this CPU when the museum got it.  Its often hard to figure out what a CPU/MCU was used in, or what it was for, its provenance.  This 6801 offers some help.  It came in an original Hitachi box, with a copy of a fax from Hitachi in Japan to the Hitachi sales office in the USA.  The fax denotes that these are qualification samples, automotive spec, and for a particular customer.  That customer is Chrysler (the automotive company now owned by Fiat).

Fax from Hitachi Japan stating use of the HD6801 samples

Also included on the fax is an original Japanese date stamp (June 1982 (Showa year 57)) .  These 6801s were fresh off the production line, having been made only a few weeks earlier.   The fax states these are for Chrysler in Huntsville, AL. with a reminder that they are “Not for Detroit” (where most of Chrysler production was.  That is an interesting addition, and important, as Chrysler did (it closed in 2011) have a very large presence in Huntsville, AL.  Huntsville is known as Rocket City, home of the Redstone Arsenal, where a large amount of US rocket, missile, and space engineering have taken place.  It was also the home of Chrysler Electronics (as well as most all of Chrysler’s military and space programs.  It was Chrysler who built the Saturn 1 and Saturn 1B upper stages for the NASA Apollo program.  Chrysler Electronics also built much of the Grown system electronics for the Apollo program as well as vehicle testing equipment for the M1 tank, the M2/3 Bradley and a host of other military programs.

Chrysler SERV – Space Shuttle Concept

Chrysler also proposed the Single-stage Earth-orbital Reusable Vehicle (SERV) during the design phase of what became the Shuttle program.

In the early 1970’s electronic use in cars was growing rapidly, leading Chrysler to greatly expand their presence in Huntsville.  These 6801s were likely for testing for cars, though it is unclear if Chrysler actually used the 6801 in their vehicles as ECUs from the mid-80’s all seem to be running the 6803 and 6805 MCUs.  Maybe if I find an early 80’s Chrysler I’ll tear out the ECU and find out.


November 22nd, 2017 ~ by admin

CPU of the Day: DEC LSI-11 Chipset

LSI-11 Chipset with EIS/FIS Chip – 1976-1977

Back in 2014 we discussed the Western Digital WD/9000 Pascal Microcomputer system.  Today we’ll look at the LSI-11 chip set, the basis of the Pascal.  Back in 1974 DEC (Digital Equipment Corporation) contracted Western Digital to design and build a 16-bit chipset to emulate the Bipolar PDP-11/05 Minicomputer.  Western Digital was paid $6.3 million for the work, and would be allowed to market and sell the resulting chipset themselves, as well as grant license to it to others (including DEC).

The LSI-11 was to be a 16-bit chipset, but was based around a 8-bit Data chips (the 1611).  The 1611 has an 8-bit ALU , 26 8-bit registers and a microinstruction register.  This is controlled by the 1621 control chip, which interprets macroinstructions from handles all the timing, as well as interrupts.  The 1621 control chip is what allows the 8-bit 1611 to be used as a 16-bit processor.  The chips are connected by an 18-bit  microinstruction bus, and a 16-bit address/data bus handles access to the rest of the system (memory/I/O).  Each microm is a 512 Word by 22-bit ROM, which can hold 80 instructions.  It is these MICROMs that allow the WD MCP1600 to function as a PDP-11/05.  The instructions in the the MICROMs (2 are required for the LSI-11) emulate the PDP-11 instructions.

DEC M7264 LSI-11 KD11-L Board from PPD- 11/03

First production of the LSI-11 chipset began in March of 1975 with shipments commencing that year.  The PDP-11/03 based on this chipset was released later that year.  The KD-11 M7264 board formed the hear of the 11/03 (as well as other DEC systems).  In typical DEC fashion it came in many flavors with different amounts of memory, as well as different instruction support.  This was completely due to the design of the LSI-11 chipset and its MICROMs .  The basic LSI-11 need 2 MICROMs to handle the basic PDP-11 instructions, the chipset however supported 4.  This mena that more instructions could be added.  One of the most common and useful additions was the EIS/FIS (Extended Instruction Set/Floating Point Instruction Set) microm.  This added 8 more instructions including MUL, DIV, FADD, FSUB, FMUL, FDIV and 2 register shifts (ASH, ASHC).  Adding the EIS/FIS chip to a standard KD-11-F board turned it into a KD-11-L (like the one pictured).

Western Digital 1611 Die –
Pauli Rautakorpi

There were other MICROMs available as well.  This included a set of 2 for support of DIBOL (Digital Business Oriented Language), a DEC language similar to COBOL.  Since the DIBOL chipset needed 2 chips a system could support DIBOL, OR EIS/FIS but not both.  MICROMs were revised as bugs were found, or faster ways of handing an instruction were made.  MICROMs revisions could also be made to support different PCB revisions.  In some ways they played the part of firmware to the PCB, as well as the instruction set for the processor.  In this way many MICROMs are specific to PCB etch revisions and other revisions of the system outside of the processor itself.  Matching the correct MICROMs, as well as Control and Data chips to the correct board is a bt of a task, and take several dozen pages of the LSI-11 maintenance manual.

Here are a few part #s to help sort things out

Data Chip
DEC 1611
Control Chip
DEC 2007C
MICROM 1 3010D/A
MICROM 2 3007D
21-11549-01 23-008B5-00 STD INST 1
21-15579-00 (1611H) 23-003C4-00 23-007B5-00 STD INST 2
21-16890-00 (1611H) 23-002C4-00 23-003B5-00 EIS/FIS
23-001C3 CP1621B14 23-009B5-00 EIS/FIS
23-001C2-01 CP1621B451 23-001B5-00 CP1631B103 STD INST 1
23-002B5 CP1631B073 STD INST 2
 23-091A5-01 CP1631B153 EIS/FIS
23-004B5 DIBOL 1
23-005B5 DIBOL 2
23-008A5-01 CP1631B-10 STD INST 1
23-007A5-01 CP1631B-07 STD INST 2

DEC M7270 LSI-11 – 1982 – All WD Chips

There are more to be found as DEC and Western Digital made many versions.  In early 1976 Western Digital licensed the MCP1600 chipset design to National Semiconductor, in exchange for some RAM technology licensing.  It is unclear if National actually made any of the MCP1600 chipset.  By 1977 DEC had started to produce the LSI-11 chip itself while continuing to source parts from Western DIgital as well.  It is common to see LSI-11 boards with DEC and WD chips mixed well into 1982.

The popularity of the PDP-11 in the 1970’s resulted in many customers for the LSI-11 based PDP’s, and their use continued well into the 1990’s with many systems continuing to be used today.  As with many such systems, they found use in industrial control and automation, where they continue to work.

November 14th, 2017 ~ by admin

CPU of the Day: Fairchild F9445: The MicroFlame Flames Out

Fairchild 9445DM – 1983 Military Temp Range

In the 1970’s many companies began to make processors based on mainframe architectures of the time. Data General with the creation of the mN601 MicroNova, TI with the TMS9900, DEC with the LSI-11 and others.  This set the stage for a pretty large showdown, as what happens when a company other then the original mainframe company creates a processor that is compatible?  This is what began to happen in the late 1970’s, and with the release of Fairchild F9440 MICROFLAME.  We’ll quote directly from the F9440 datasheet “Though structurally different from the CPUs of the Data General NOVA line of minicomputers, the 9440 offers comparable performance and executes the same instruction set.”  Specifically the bi-polar F9440 could

DGC mN602E – MicroNova – Data Generals Own single chip Nova

run most the code from the very popular Data General Nova 2 computer system.  Obviously, as Fairchild states, it is structurally different, as its Fairchilds own hardware LSI implementation.  The idea that an instruction set could be copyrighted was already being tested, and by all appearances at the time it was assumed that an Instruction set, could not be copyrighted.  This certainly helped in the wide adoption late on of x86.  A different way of protecting computer architectures had to be created then.

The first salvo was fired by Data General, in a lawsuit claiming that Fairchild’s F9440 enticed DG users to break their software license agreements.  DG’s way of ensuring they had control of their customers was to add a section in the software license agreement that the software could ONLY be ran on Data General hardware, even if it COULD run on a Fairchild F9440 (or any other hardware) it was a violation of the license to do so.  In 1978 Fairchild counter-sued, claiming that such a license was anti-competitive and seeking $10 Million in damages as a result of DG’s original suit.

9445 DIe shot (partial)

To add fuel to the fire, Fairchild announced the F9445, the MICROFLAME II.  The F9445 was built with the same I3L (Isoplanar Integrated Injection Logic) technology but on a 2-Micron process instead of the 3-Micron process of the 9440 and contained over 5000 gates.  The F9445 could was compatible with the Nova 3 and Fairchild claimed it would be 10 times faster then the Nova 3.   The F9445 was announced in 1978 but development issues (this was one of the largest, fastest bi-polar designs) took some time and led to many delays. In 1979 Fairchild, low on cash, was purchased by  Schlumberger Limited, an oil field services company, for $425 million (Exxon responded by buying Zilog in 1980).  Production of the F9445 finally began in the first half of 1981, with deliveries beginning late in the year.  Initial devices ran at 16MHz (an increase from 12MHz in the original 9440) and 20 and 24MHz versions were released later.  The F9445 required a single +5VDC supply and a 300mA current supply dissipating about 1.5W (compared to 1W for the 9440).  The MICROFLAME II was aptly named, they ran rather hot (not unusual for their technology though). Like the F9440 the 9445 is a 16-bit processor and could directly address 128K of memory.  It adds a stack pointer and hardware multiply, while retaining the same 50 instructions from the 9440 but increases the addressing modes supported from 8 to 11 (needed to emulate the Nova 3).

Fairchild F9450-15DC – MIL-STD-1750A processor based on the architecture of the F9445

Interestingly the F9445 provided the base for another Fairchild processor.  The F9445 took Nova instructions, decoded them and ran them on its hardware, it was, in other words, a micro-coded processor.  Microcoded processors can be useful as the microcode can be changed to support an entirely different instruction set. That’s exactly what Fairchild did with the F9450, a processor designed to execute the just released MIL-STD-1750A 16-bit instruction set.

Data General was not pleased, so again sued, claiming that Fairchild probably stole proprietary information in order to design the F9445.  Fairchild was not alone in the action as their were other companies who made Nova emulating hardware, as well as those who made software that would run on a Nova.  The lawsuits (no less then 11 of them) continued well into the 1980’s.  By 1986 Data General was struggling, the case continued, and was not going in their favor.  In September of 1986, a month before the trial for damages was to begin, Data General settled, paying Fairchild $52.5 million.  Eight years after the fireworks began, the original F9440 MICROFLAME had not been made in years, the Nova 2 and Nova 3 were no longer made as well.  The lawsuits destined the F9440 and the F9445 to failure, but they made their mark in setting precedent in lock-in, and how Instruction Sets can be used.

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September 30th, 2017 ~ by admin

Processing the Page Turn

DSC Page Turn Processing Board. 6x 16bit ALUs – 1989

This board isn’t strictly a CPU but it is a processor of sorts.  I actually purchased this board as it was described as a DEC board, with not a great picture, having not seen a DEC board with LOGIC ALUs on it I bought it.  When it arrived I found it wasnt DEC at all but DSC, Digital Services Corporation.  DSC was a video effect company formed in the early 1980’s and later bought out by Chyron, one of the leaders of television video effects hardware.

In the 1980’s, effects on television were generally done in hardware, and required rather specialized hardware for each type of effect.  The most primitive were CG (Character Generators) that added captions typically to the lower third of the screen for a broadcast, like the name of the person speaking, etc.  As hardware capabilities increased, other effects could be generated, such as a video or image overlay, perspective changes or the page turn effect.

Logic L4C381GC-40 – 4x4bit ALU’s implemented in CMOS

These effects generally were handled by an effects processing system, with each effect having its own board in the system responsible for that effect.  Adding an effect required buying an effects board and installing it in the system.  This particular board from DSC handles the Page Turn Effect.  This is where one video transitions to another video with the look of a turning page.  It requires 3 inputs, the first video, the second video being turned to, and a typically solid color/image that represents the back of the page.  Here is a quick example on YouTube.  Today this can be handled by most any video editing software on a general purpose computer, but in 1989 there wasn’t a computer that could do this in near real time.

This board is built around 6 LOGIC L4C381GC-40/55 ALUs and 6x LOGIC LMU216JC-55 Multipliers.  The 4C381s are a 16-bit CMOS ALU, based on 4 74381 4-bit ALU,s a Carry Generator and interface logic.  Basically 1970’s technology updated to CMOS.  They handle 16 bit Addition, Subtraction and basic logic (XOR/OR/AND).  The LMU216s are 16 x 16-bit Parallel Multipliers.  They are the equivalent of the old AMD Am29516 that was cloned by TRW, Cypress and IDT.

LOGIC LMU216JC-55 – 16×16 CMOS Multiplier

The rest of the board consists of 6x64Kb or Video RAM, shift registers, and all the control logic (in PALs) to provide the instructions for the ALUs and multipliers.  The arrangement of the board suggests a 64-bit computation section and a 32-bit section.  Just as in the 1970’s the ALUs and multipliers have been used to make a custom processor, with a very specific instruction set and purpose and do so at a speed that would be compatible with broadcast television.  Sitting on one’s couch in the 1980’s watching TV and seeing a cool page turn effect one would think, ‘Hey that’s cool!’, yet have no idea that an entire processing system had to be designed, built and coded for that one second of television.

Russian Translation now available here by Vlad Brown

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July 2nd, 2017 ~ by admin

ITT AN/ALQ-136 Countermeasures Processor – Bit Slice with a Bite

ITT 80063SM-A-919797 – AN/ALQ-136(V)I Processor. The 2901B’s are the 4 larger dies in a row, middle right.

Military computing applications require many custom designs, as they are very mission specific.  A great example is this ITT hybrid processor.  It was designed and used for the AN/ALQ-136(V)1 CMS (CounterMeasures System) for the AH-1F Cobra Attack helicopter.  Two of these hybrids are used in the system, one for the Mod Recovery board, and one for the SLO processor board.  These boards are used to detect hostile pulse RADAR systems, analyze them, and begin jamming based on what type they are.

This requires relatively fast processing, and a generally custom design.  Today a modern DSP processor could handle this task without issue.  However in the early 80’s (the AN/ALQ-136 debuted in 1982) DSP processors were in their infancy.  In 1982 a fast custom processor needed to be built with bit-slice elements.  In this case the very versatile AMD 2901 was used.  The ITT hybrid integrates 4 AMD AM2901B processor dies, as well as associated memory and interfacing elements.  The single package contains almost 100 dies, and many discrete components.  It is built on a ceramic substrate with gold traces, and sealed in a metal package.  This is required to protect the digital components of the system from electronic interference, whether from external sources, or from the helicopters own RADAR systems.  The AN/ALQ-136 is designed to prevent the Cobra from being successfully targeted by RADAR guided missiles, failure means a strong possibility that the helicopter gets hit, not something its crew would like to deal with.

4x AMD AM2901B Dies.

The 4 AMD 2901Bs run at 16MHz (50% faster then the original 2901s) and are made with ECL; together they provide 16-bit processing of the incoming RADAR signals. The SLO (Side Lobe Opposition) and MOD Recovery (Modulation Recovery) are used to determine the exact type of the enemy RADAR.  Each RADAR has a distinct characteristic that the CMS can match and respond to.  The CMS is programmed to respond to the radar signals of the most critical threat weapon systems anticipated to be encoun

Israeli AH-1F Cobras – Now Retired/Transferred to Jordan.

tered in the hostile environment.  These signatures are stored in the hybrids ROMs as well as the desired response to them.  Updates likely remain replacing these hybrids with updated versions.  New countermeasures systems (such as the 136’s replacement, the AN/ALQ-211) are more easily upgradeable to new threats.

The AH-1F Cobra continues to fly with the air forces of several countries around the world, notably Pakistan, Jordan, and Turkey.  The United States Forest Service also operates 25 AH-1F Cobras for wildland fire use, but it is rather unlikely that the countermeasures on these are operable, let alone needed.

June 20th, 2017 ~ by admin

Intel’s First: The 3101 64-bit Bipolar Memory

Intel 3101 Memories, from late 1969 early 1970.

Today when we think of Intel, the ‘processor company’ comes to mind.  It was now what they are best known for, but when Intel began in 1969 they did not make processors, they made memory, specifically SRAM, DRAM, and EPROMs.  The very first product Intel released, in April of 1969, was the 3101 64-bit SRAM.  It was made on the new, and fast Schottky Bipolar process.  This made it very fast (access times of 60ns) but very power hungry.  It dissipated 525mW, over half a watt, for 64-bits of memory.

Two months later Intel released the 1101, which was developed at the same time as the 3101.  It was made on a PMOS process, which allows much greater densities, the 1101 was 256-bit SRAM chip.  The sacrifice is speed, the 1101 is a bit slow, with access times of around 1.5us.  Operating power was 700mW but in standby mode it only drew 350mW.

Very Early Burroughs “D” NanoMemory board with 32 Intel 3101 memories (picture from Evan Wasserman )

Computer makers were eager for single chip memories, they allowed for more dense memory systems.  One of the first users of the 3101 was Burroughs in their ‘D’ machine, a computer designed for the Air Force in 1969.  It used 3101s for its ‘nanomemory’ organized as 64×56 bits (needing 56 3101s if they were used for all the nanomemory.  Other notable users was in implementing the stack in the Datapoint 2200.  The 2200 is the grandfather of x86, its architecture was the basis for the Intel i8008, which then led to the 8080 and 8086 processors.  The first Xerox Alto’s also used the Intel 3101, arguably the first GUI implementation.

The 3101 evolved as Intel learned the process of making chips, and assembling them.  This is notable in looking at die shots of two 3101s with lot codes likely only a few months apart.  Ken Shirriff, a fellow collector, was donated a pair of 3101s nearly identical to those pictured, for decapping and die shots, by Evan Wasserman (who donated several to the CPU Shack Museum as well).  If addition to the package difference (not the larger lid on the later one) there is some die changes as well.  The bonding pads were made much larger, likely to ease the assembly, and the main VCC line on the top of the die was made smaller.  Connections to bond pads were also cleaned up and refined.  The logic of the device appears unchanged.

3101 dies. Left is lot 898, right is the later 1116. Click for much larger version. Die photos provided by Ken Shirriff

Through the 1970’s and well into the 1980’s memory devices were by far Intel’s largest revenue source.  It wasn’t until fierce competition in the memory market that this changed.  Had it not been for IBM adopting x86, things could have been much different and more difficult for Intel.  The rapid adoption of x86 gave Intel a new revenue stream, and one that was less likely to be pressured by commodification as was happening to memory devices.



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CPU of the Day

June 5th, 2017 ~ by admin

SiFive FE310: Setting The RISC Free

SiFive FE310 RISC-V Processor. Early LSI SPARC Processor for size comparison. Both are based on U.C. Berkeley RISC designs.

The idea of RISC (Reduced Instruction Set Computer) processors began in education, specifically University of California, Berkeley in the early 1980’s, and it was out universities that some of the most famous RISC designs came.  MIPS, still in use today, started life as a project at Stanford University, and SPARC, made famous by Sun, and now made by Oracle and Fujitsu, started life as a Berkeley University project.  Universities have continued to work with RISC architectures, for research and teaching.  The simplicity of RISC makes them an ideal educational tool for learning how computers/processors function at their basic levels.

By the late 1980’s RISC had begun to become a commercial revolution, with nearly every player having their own RISC design.  AMD (29k), Intel (i960), HP (PA-RISC), Weitek (XL8000), MIPS, SPARC, ARM, Hitachi (SH-RISC), IBM (POWER), and others offered their take on the RISC design.  Most were proprietary, while a few were licenseable, none were open architectures for anyone to use.

Unfortunately, outside of the university, RISC processors are not as simple.  The architectures, and their use may be, but licensing them for the design is not.  It can often take more time and effort to license a modern RISC processor then it does to actually implement it.  The costs to use these architectures,both in time and money often prohibit their very use.

SiFive FE310 – Sample Donated by SiFive. Full 32-bit RISC on a 7.2mm2 die in a ~36mm2 package

It is out of this that SiFive began.  SiFive was founded by the creators of the first commercially successful open RISC architecture, known as RISC-V.  RISC-V was developed at Berkeley, fittingly, in 2010 and was designed to be a truly useful, general purpose RISC processor, easy to design with, easy to code for, and with enough features to be commercially useful, not limited to the classroom.  It is called the RISC-V because it is the fifth RISC design developed at Berkeley, RISC I and RISC II being designed in 1981, followed by SOAR (Smalltalk On A RISC) in 1984 and SPUR (Symbolic Processing Using RISC) in 1988.  RISC-V has already proved to be a success, it is licensed freely, and in a way (BSD license) that allows products that use it to be either open, or proprietary.  One of the more well known users is Nvidia, which announced they are replacing their own proprietary FALCON processors (used in their GPUs and Tegra processors) with RISC-V.  Samsung, Qualcomm, and others are already using RISC-V.  These cores are often so deeply embedded that their existence goes without mention, but they are there, working in the background to make whatever tech needs to work, work.

The RISC-V architecture supports 122 instructions, 98 of which are common to almost all prior RISC designs and 18 common to a few.  Six completely new instructions were added to handle unique attributes of the architecture (using a 64-bit Performance Register in a 32-bit arch.) and to support a more powerful sign-injection instruction (which can be used for absolute value, among other things). It uses 31 32-bit registers (Register 0 is reserved for holding the constant ‘0’) with optional support for 32 floating point registers.  True to the RISC design, it is a pure Load/Store processor, the only accesses to memory are via the Load/Store instructions.

Intel 4004 with 5 SiFive RISC Processors. The 4004 was meant for a calculator. The FE310 is meant for whatever your mind may dream up.

SiFive is unique among RISC IP companies.  They not only license IP but also sell processors and dev boards.  The FE310 (Freedom Everywhere 310) is a 320MHz RISC-V architecture with 16K of I-cache and 16K of scratchpad RAM fabbed by TSMC on a 180nm process. Even on this process, which is now a commodity process, the FE310’s efficient design results in a die size of only 2.65mm x 2.72mm.  On a standard 200mm wafer , this results in 3500 die per wafer, greatly helping lower the cost.  Its an impressive chip, and one that is completely open source.  What is more impressive is licensing SiFive cores, it is a simple and straightforward process.  The core (32 bit E31 or 64-bit E51) can be configured on SiFive’s site, with pricing shown as you go.  The license is a simple 7 page document that can be signed and submitted online.  Pricing starts at $275,000 and is a one time fee, there are no continuing royalty payments.  The entire process can be completed in a week or less.

In comparison, ARM, the biggest licensor of RISC processors, does not publish pricing, charges 1-2% royalties on every chip made, and has a license process that can take over a year.  The base fees start at around $1 million and go into the 10’s of millions, depending on how you want to use the IP, where it will be, and for how long.  For many small companies and users this is simply not feasible, and it is these smaller users that SiFive wishes to work with.  Licensing a processor for the next great tech, should not be the hurdle that it has become.  Many great ideas never make it to fruition due to these roadblocks.  We look forward to finding SiFive processors and cores in all sorts of products in the future.

Thanks to SiFive for their generous donation of several FE310 processors to the CPU Shack Museum.