September 6th, 2015 ~ by admin

The Electronika MK1 red3 PDP-11 Chipset and Tetris

Soviet Electronika MK1red3 - F-11 Clone and implementation of PDP-11

Soviet Electronika MK1red3 – F-11 Clone and implementation of PDP-11

The DEC F-11 ‘Fonz’ implementation of the PDP-11 was released in 1979 and was DEC’s second ‘LSI’ implementation of the PDP.  Like its predecessor it was a multi-chip implementation, consisting at its root of a data chip (DC302) and 1-9 control chips (DC303).  The DC303 control chips were essentially a large ROM/PLA with a few extra features added for interrupts and sequencing.  They formed the microcoded instruction set that drove the 16-bit ALU and registers of the DC302.  This is why more then one were supported.  Expanding the instruction set was as ‘simple’ as adding more DC303 chips with these instructions encoded.  The basic LSI11/23 came with one 303 and one 302.  A second IC could be added to support floating point, which included a pair of DC303 chips implementing the floating point instructions.  A MMU (DC304) was also supported, and required when using the FP option.

DEC 570000101A1 F11 Floating Point Option with 2x 303E Control chips

DEC 570000101A1 F11 Floating Point Option with 2x 303E Control chips

The Soviets also widely adopted the PDP-11 architecture.  Likely because it was designed to be rather hardware independent.  It could be implemented in many different ways, which meant the Soviets could adopt/implement it on their own.  Electronika was part of the Soviet industrial complex in Voronezh, Russia making many different IC’s, but also was tasked with making consumer devices (computers and calculators etc, that were in very short supply.  The Electronika 60 was one of the first PDP-11 computers they made, and it implemented a copy of the DEC Fonz processor.  Electronika combined the standard chipset, and FPU onto a single large MCM with all 4 IC’s (the MMU remained separate) called the MK1 red1 (and later the MK1 red3)

Tetris Electronika 60 - Text Only

Tetris Electronika 60 – Text Only

KH1811VM1 = DC302 – 21-15541 Data Chip (16-bit ALU etc)
KH1811VU1 = DC303 – 23-001C7 standard instruction set
KH1811VU2 = DC303 – 23-002C7 FP instruction set Part 1
KH1811VU3 = DC303 – 23-003C7 FP instruction set Part 2

It was on this chipset, on a Soviet Electronika 60 that Alexey Pajitnov wrote the very first version of the still famous game of Tetris back in 1984.  A game that was very popular, and very widely copied in the West, even to this day.  (the copying of technology most certainly went both ways)

April 22nd, 2014 ~ by admin

Soviet K573RF23 and the Mark of Quality

Soviet Vostok K573RF23 - 2kx4 - 1984

Soviet Vostok K573RF23 – 2kx4 – 1984

This EPROM, made in November of 1984 at the Soviet Vostok factory in Novosibirsk started life as a 2716 2kx8 EPROM.  A Soviet 2716 would be marked as 573RF2, whereas this particular example is marked 573RF23.  The die is a 2716 that was found to be defective, and thus converted to a  2kx4 EPROM, this is denoted by the adding of the 3 to the part number.  This certainly was not an uncommon procedure, even Intel regularly sold 2708 EPROMs as 2704s, whether to use a die with an imperfection, or to simply meet demand.

There are two other interesting markings on this particular EPROM.  First is the CCCP logo, this is the State Quality Mark of the USSR.  This quality mark was used to signify that products met the following conditions:

  • “meets or exceeds the quality of the best international analogs”,
  • parameters of quality are stable,
  • goods fully satisfy Soviet state standards,
  • goods are compatible with international standards,
  • production of goods is economically effective and
  • they satisfy the demands of the state economy and the population.

Meeting these conditions allowed the factory to sell such devices at a 10% premium.  So not only was Vostok able to pass a defective part as a quality part, they were able to do so and make a bit extra revenue.  Thats something Intel would be quite envious of.

Some references show that 573RF23 as being the equivalent of a 2758 EPROM (5V 2708).  This is in fact incorrect.  A 2716 converted to a 2708 is done so simply by removing a single address line (going from 11 to 10)  The 573RF23 retains 11 address lines, but it removes 4 data lines, thus making it 2kx4, same number of address locations, but each locations contains only 4 bits, vs 8 bits.  Rewiring address lines likely did not allow for a working EPROM due to where the defect was, thus cutting the word size down.  The first condition of the State Quality Mark is that said EPROM should meet or exceed the best international analog.  Intel did not make a 2kx4 EPROM, the closest western analog would be the Harris/Intersil IM6657, though it was made in CMOS, vs the 573RF23s NMOS, so one could say that it was easy to beat a analog that did not exist.

The other mark on this EPROM is OTK, which literally means “Technical Control Department,” in others words this part passed the quality control dept, hopefully after it was converted to the lower capacity device, and them marked with the State Quality Mark.  Perhaps it was the best NMOS 2kx4 EPROM the world was to see, certainly it came in a beautiful package.

February 20th, 2011 ~ by admin

Russian Computers on the Buran Shuttle

In the 1970’s and the 1980’s the Soviets developed and successfully flew their own version of the Space Shuttle.  It was called the Buran.  In many ways it was an enhancements of the US Space Shuttle, based on what the Soviets saw as deficiencies in the US design.  One of the biggest differences was the piloting.  The US STS (Shuttle Transport System) was designed to be a crewed vehicle.  The computers assisted the pilot/co-pilot in launch, orbit, and recovery.  Many of the functions on the STS can be handled by the computers (the Flight Computers were based on the IBM System/4 Pi) but the pilot was needed to handle the rest.  The Soviets, on the other hand, designed the Buran to be able to launch, orbit, and land fully automatically.  This meant the computers has to be very robust, and the programming even more so.  The computers had to respond quickly to chaning inputs, and be able to handle failures gracefully.  While each mission would have a set profile, unknown conditions would cause deviations that the computers must detect, analyse, and properly handle.  Preferably without wrecking the multi-billion ruble space craft.

Buran Computer

The main computer of the Buran is actually 4 independent systems that receive the same inputs.  The clock in generated externally (with 4 backups) so that each computer is in perfect time (the STS uses software to ensure the computers are in time, rather then hardware).  Redundancy is achieved by the voting system. Each computers outputs are compared, if one computers output is different, it is automatically shut down, leaving the 3 remaining computers.  These computers are powered by a clone of the DEC PDP-11.  The Soviet’s ‘acquired’ a few PDP/11 systems and then copied and cloned them into many different systems.  The most common is the 1801 a 5MHz NMOS PDP-11 type device.  The Buran used the 1806, which is the CMOS version.   Here is a general overview of the flight computer.

Angstrem CMOS N1806VM2 - MicroVAX

In addition to the 1806 there were many sub-systems with their own processors.  Details on these are a bit thin, however looking at other Soviet space computer designs it is very likely that many of these used the 134IP3 series of ALUs (a clone of the 54L181 TTL 4-bit ALU).  This chip is also used in the Argon-16 and Argon 16A computers of the Soyuz and Progress spacecraft that are still in use today.  Bit-slice devices were used extensively for many Soviet designs as it gave them a great ability to design custom processors to meet the applications needs.  The Argon-17, which was used for anti-ballistic missile work, was based on the 583 series, an 8-bi slice processor.  The C100 and C101 computers (used as weapons computers on the MiG-29) also use a BSP design.

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October 11th, 2010 ~ by admin

Soviet Beauties: Processors from behind the Iron Curtain

The Soviet Union’s electronic programs were mainly focused on copying and cloning Western devices.  Either by simple theft, or painstaking reverse engineering.  They made clones of devices such as the Intel 8080, and the AMD 2901 as well as simple TTL.  The Soviets also made many single and multi-chip versions of the venerable DEC PDP-11 computer system.  Many of these have no Western analogs, they were pure creations of the Soviet industry.

Soviet Kvantor 580VM80 - Intel 8080 - Milspec

While Western chips rapidly transitioned into mostly black plastic by the 1980s the Soviets did not.  The 8080 above was made in 1991 though looks like something from the 70’s. Black plastic is cheap, and easy to make, but it isn’t great looking. The Soviets on the other hand made some of the best looking (if not always functioning) processors of the time.

Soviet J-11 Missing the chips

Here is just the substrate (its a non finished example) of a Soviet clone of the DEC J-11 CPU. Not often do you see a brilliant blue processor.

Soviet Angstrem K1801VM1

This is a nice pink ceramic Soviet PDP-11 5MHz CPU. Again this was made in 1991.  Its a form of surface mount package that was used extensively for industrial and military designs.  Just as the PDP-11 was used by the American military throughout the 70’s and 80’s. the Soviets used it (and now Russians) in todays times.

Soviet era CPUs are very interesting to collect.  Each state run factory had their own logo which was typically (but not always) put on the chip. Many part numbers were made by more then one factory. Most chips have a western analog, but not all.  Soviet chips also were ever so slightly different sized then Western ones. The Soviets used a pin spacing of 2.5mm where as the West used 0.1″ (2.54″), rather noticeable on a 40 pin DIP. Reading/translating some of the Cyrillic  based characters can be a chore but really when you get to see things like this…

Electronika J-11 - Image courtesy of iguana_kiev

Can you really complain?