Archive for the 'Research' Category

July 3rd, 2016 ~ by admin

Juno Joins Jupiter: And Brings Some Computers For The Trip

Juno - RAD750 Powered Mission to Jupiter

Juno – RAD750 Powered Mission to Jupiter

NASA’s Juno mission to Jupiter arrives in just about a day, after a 5 year journey that began in August of 2011 aboard an Atlas V rocket.  The Juno mission is primarily concerned with studying the magnetic fields, particles, and structure of Jupiter.  Finding out how Jupiter works, and what its core is made of are some of Juno’s goals.  None of the experiments need a camera, but NASA decided, in the interest of public outreach and education, that if you are going to spend $1 billion to send a probe to Jupiter, it probably should have a camera.  Energetic particle detectors, Magnetometers, and Auroral Mappers are great for science, but what the public is inspired by is pretty pictures of wild and distant worlds.

Juno is powered by a now familiar computer, the BAE RAD750 PowerPC radiation hardened computer.  It operates at up to 200MHz (about the processing power of a mid 1990’s Apple Computer) and includes 256MB of Flash memory and 128MB of DRAM.  It (and the other electronics) are encased in a 1cm thick titanium radiation vault.  Flying in a polar orbit around Jupiter, Juno will experience intense radiation and magnetic fields.  The probe is expected to encounter radiation levels in the order of 10Mrads+.  The vault limits this to 25krads, within what the electronics can handle.  It should be noted that a dose of 10krads is fatal in most cases.  This intense of radiation will degrade the prober, even with shielding, resulting in a mission life of only 37 orbits (a little over a year) before the probe will be gracefully crashed into Jupiter.

Read More »

March 13th, 2016 ~ by admin

Part 3: Vintage IC Collecting – The How.

In Part 1 of our three part series on IC collecting we discussed why to collect vintage computer chips. For Part 2 we covered what to collect, how to set and keep a focus in your collection. For the final Part we’ll cover some of the ways of how to find and collect the IC’s you want.

Part 1: Why Collect Vintage Chips?
Part 2: What Vintage Chips should I Collect?
Part 3: How do I collect Vintage IC’s?

There are two main parts of the How of IC collecting. Where to I get my chips? and Where do I put them?  For most collectors cost is a concern, for the right money you can have most any chip, but since i have yet to find the dollar/Euro/yen tree cost is a factor in acquiring chips.  One of the greatest sources of chips is eBay.  Several categories in particular are a good source of chips, IC?Processors in the Business/Industrial category, the CPU/Processors and Vintage categories in Computing, and Scrap/Recovered Gold.  Of these Scrap Gold can yield some of the most interesting chips.  Scrap sellers in general though have no idea about what they are selling (as far as collectibility) but most are happy to work with you.  If you win a lot with a nice chip in it, send the seller a note to pack the chips well, and in most cases they will.  They are sold as scrap though so keep that in mind if they don’t come in perfect shape. This can be a good chance to learn the art of pin straightening.

Read More »

March 1st, 2016 ~ by admin

Part 2: Vintage IC Collecting – The What.

Where do I start? Where do I end? Focus!

Where do I start? Where do I end? Focus!

In Part 1 of our three part series on IC collecting we discussed why to collect vintage computer chips.  For Part 2 we’ll cover what to collect. which is the most important part of collecting (not just IC’s but anything).

Part 1: Why Collect Vintage Chips?
Part 2: What Vintage Chips should I Collect?
Part 3: How do I collect Vintage IC’s?

There are millions of different IC’s made since the dawn of the IC in the 1950’s, obviously it would not be prudent to try to attempt to collect all of them, so one needs to set a focus for their collection.  The earlier this is done, the easier collecting will be, and the less chance of going insane, broke, or both.  The CPU Shack, as the name implies, began collecting just CPU’s, the brains of computers.  Through the years (and due to things being donated to the museum) this has expanded to microcontrollers, SoCs. UV-EPROMs. GPU’s, and even the occasional DSP.  It’s a broader slice of IC’s then most would want to attemp, at least when starting.  So let’s figure out ways to gain a focus in collecting.

Read More »

February 18th, 2016 ~ by admin

Part 1: Vintage IC Collecting – The Why.

First Start of IC Collecting

First Start of IC Collecting

This will be the beginning of a three part series on Vintage IC Collecting, as I get asked a lot, ‘why do you collect computer stuff?’ and How do you do it? Where do you find chips etc.

Part 1: Why Collect Vintage Chips?
Part 2: What Vintage Chips should I Collect?
Part 3: How do I collect Vintage IC’s?

These really are the fundamentals to collecting/curating anything, and are important if you wish to have any structure to your hobby of collecting.  Collecting itself seems to be built into human nature, and psychologists and evolutionary scientists have many theories as to why.. Freud, who else, claimed that people collect things due to ‘unresolved toilet training issues.’ Others see collecting as a evolutionary strength, that allowed for a better chance of survival, those that collected scarce resources, had a better chance of living to procreate.

Myself, I started collecting coins when I was young, among other things.  While scrapping out computers in High School I figured the processors should be saved, as the ‘brains’ of the computer, and thus my hobby, and the museum, began.

The Collection Progresses

The Collection Progresses

There really has become two main reasons for continuing to do so.  First, I see a need to preserve some small portion of the technology that has driven us to where we are today, and where we are going.  Second, its genuinely fun, the hunt for new chips, the research into finding where they were used, and why they were made and the camaraderie with fellow collectors.

This leads us to the Why, specifically for collecting Vintage IC’s.  Many assume that those who collect computer chips will be ‘a bunch of nerds’ and while some certainly are, there is a great variety.  Like other collecting areas, there are those who collect for economic reasons, they see a good deal, buy it, with the intent of reselling it for profit at some later date, and there is certainly nothing wrong with this.  Others have some historical connection with the chips they collect.  They may be retired Electrical/Computer Engineers, programmers and the like, that see collecting as a way to preserve some of what they did.

It gets big quickly without proper focus

It gets big quickly without proper focus

For some collecting computer chips is a matter of convenience, they have ready access to them (recycling, etc) and are drawn to the fact, that like coins, IC’s have an extrinsic value in their rarity, obscurity, or provenance, but also some intrinsic value in the precious metals they contain.  Computers chips also have the benefit that their entire history is contained in a period of time that numbers in the decades, 50 years, shorter than an average human lifetime, contains the current sum of IC history.  This can be seen to make the hobby more ‘manageable’ though we will see if Part 2, that this may not be the case.

For some, computers chips are shiny, pretty, and look ‘cool’ and thats all thats needed, they collect not for any historical, or technological reason, but for the fact that they like neat looking ‘stuff’.  Some collect very large/gold chips only for this reason, or wafers, because they are drawn first, to their beauty.
On the extreme of this is those, as a fellow collector in Romania once told me:

“Basically when I saw in the same place 3 different objects of the same type, my first thought is ” I should start a new collection”

And sometimes, that’s all it takes to get started.  Next week we will explore the What of collecting, how to determine what specific type of IC’s you want to collect, and figuring that out early is so important.

February 8th, 2016 ~ by admin

Reverse Engineering the ARM1 Processor

VLSI VL2333-QC ARM ACORN - ARM2 (Adds MULT instruction in hardware) 1987

VLSI VL2333-QC ARM ACORN – ARM2 (Adds MULT instruction in hardware) 1987

Ken Shirriff has an interesting article on reverse engineering the original ARM1 processor (as designed by ARM, and implemented by VLSI).  He goes right to the silicon to form a transistor level model/emulator of the chip.  Back in 1986 when the ARM was designed and released, it wasn’t very well known, being used in very few devices.  This continued for over a decade surprisingly. being used in niche markets (the Apple Newton, the DEC StrongARM on RAID cards, etc).  It wasn’t until the 2000’s that this processor startup from England became the powerhouse it is today.  Two major developments drove this, mobile, and multimedia.  The ARM architecture was powerful, small, and easy on the power budget, this obviously was a benefit for mobile, but also proved very useful in dealing with multimedia processing, such as controllers on DVD players, digital picture frames, MP3 players and the like.  Today, hundreds of companies license and use the architecture and it is found in devices now numbering in the billions.

Tags:

Posted in:
Research

October 15th, 2014 ~ by admin

Has the FDIV bug met its match? Enter the Intel FSIN bug

Intel A80501-60 SX753 - Early 1993 containing the FDIV bug

Intel A80501-60 SX753 – Early 1993 containing the FDIV bug

In 1994 Intel had a bit of an issue.  The newly released Pentium processor, replacement for the now 5 year old i486 had a bit of a problem, it couldn’t properly compute floating point division in some cases.  The FDIV instructions on the Pentium used a lookup table (Programmable Logic Array) to speed calculation.  This PLA had 1066 entries, which were mostly correct except 5 out of the 1066 did not get written to the PLA due to a programming error, so any calculation that hit one of those 5 cells, would result in an erroneous result.  A fairly significant error but not at all uncommon, bugs in processors are fairly common.  They are found, documented as errata, and if serious enough, and practical, fixed in the next silicon revision.

What made the FDIV infamous was, in the terms of the 21st century, it went viral.  The media, who really had little understanding of such things, caught wind and reported it as if it was the end of computing.  Intel was forced to enact a lifetime replacement program for effected chips.  Now the FDIV bug is the stuff of computer history, a lesson in bad PR more then bad silicon.

Current Intel processors also suffer from bad math, though in this case its the FSIN (and FCOS) instructions.  these instructions calculate the sine of float point numbers.  The big problem here is Intel’s documentation says the instruction is nearly perfect over a VERY wide range of inputs.  It turns out, according to extensive research by Bruce Dawson, of Google, to be very inaccurate, and not just for a limited set of inputs.

Interestingly the root of the cause is another look-up table, in this case the hard coded value of pi, which Intel, for whatever reason, limited to just 66-bits. a value much too inaccurate for an 80-bit FPU.

October 11th, 2014 ~ by admin

Why the Zilog Z-80’s data pins are scrambled

Zilog Z80A CPU -1978

Zilog Z80A CPU -1978

Ken Shirriff has an excellent write up about the Zilog Z80 and why its pin-out, specifically the Data lines, is a bit convoluted.  Rather then being in order (such as D0-D7) the original Z80 is D4,D3.D5,D6,D2,D7,D0,D.  Its functional but its not pretty and can lead to some interesting PCB layout issues.  Ken uses data/imaging from the Visual6502 project to look at the on die reasons for this.  Essentially it came down to saving die space. there literally was not enough room to route the data connections within the confines of the die size.  Keeping the die size small allowed Zilog, and its many second sources), to keep prices down.  In the early days Zilog contracted Mostek to make much of their processors, so die size and the associated cost were a big issue.

Posted in:
Research

November 1st, 2013 ~ by admin

nCube and the Rise of the HyperCubes

nCube/2 Processor - 20MHz The logo is a tesseract - 4-way Hypercube

nCube/2 Processor – 20MHz
The logo is a Tesseract – a 4-way Hypercube

In 1983 Stephen Colley, Dave Jurasek, John Palmer and 3 others from Intel’s Systems Group left Intel, frustrated by Intel’s seeming reluctance to enter the then emerging parallel computing market.  They founded a company in Beaverton, Oregon known as nCube with the goal of producing MIMD (Multiple Instruction Multiple Data) parallel computers.  In 1985 they released their first computer, known as the nCube/10.  The nCube/10 was built using a custom 32-bit CMOS processor containing 160,000 transistors and running initially at 8MHz (later increased to 10).  IEEE754 64-bit floating point support  (including hardware sqrt) was included on chip.  Each processor was on a module with its own 128KB of ECC DRAM memory (implemented as 6 64k x 4 bit DRAMs.)  A full system, with 1024 processor nodes, had 128MB of usable memory (160MB of  DRAM counting those used for ECC).  From the outset the nCube systems were designed for reliability, with MTBFs of full systems running in the 6 month range, extremely good at the time.

The nCube/10 system was organized in a Hypercube geometry, with the 10 signifying its ability to scale to a 10-way Hypercube, also known as a dekeract.  This architecture allows for any processor to be a maximum of 10-hops from any other processor.  The benefits are greatly reduced latency in cross processor communication.  The downside is that expansion is restricted to powers of 2 (64, 128, 256, 512 etc) making upgrade costs a bit expensive as the size scaled up.  Each processor contained 22 DMA channels, with a pair being reserved for I/O to the host processor and the remaining 20 (10 in + 10 out) used for interprocessor communication.  This focus on a general purpose CPU with built in networking support is very similar to the Inmos Transputer, which at the time, was making similar inroads in the European market.  System management was run by similar nCube processors on Graphics, Disk, and I/O cards.  Programming was via Fortran 77 and later C/C++. At the time it was one of the fastest computers on the planet, even challenging the almighty Cray.  And it was about to get faster.

Read More »

March 2nd, 2013 ~ by admin

Chuck Moore: Part 2: From Space to GreenArrays

Part 2 of my abbreviated biography of Chuck H. Moore’s processor designs.  Part 1 covered the early days of Novix, and the RTX2000.

Patriot Scientific IGNiTE - Based on the Sh-Boom

Patriot Scientific IGNiTE – Based on the Sh-Boom

Moore was not content to just create one processor design, or one company.  In the 1980’s he also ran Computer Cowboys, a consulting/design company.  In 1985 he designed the Sh-boom processor with Russell H. Fish III.  This was a 32-bit stack processor, though with 16 general purpose registers, that was again designed with Forth in mind.  It was capable of running much faster then the rest of the system so Moore designed a way to run the processor faster then the rest of the board, and still keep things in sync, innovative at them time, and now standard practice.  The Sh-Boom was not a particularly wide success and was later licensed by Patriot Scientific through a company called Nanotronics, which Fish had transferred his rights to the Sh-Boom to in 1991.  Patriot rebranded and reworked the Sh-Boom as the PSC1000 and targeted it to the Java market.  Java byte code could be translated to run in similar fashion as Forth on the PSC1000 and at 100MHz, it was quick.  In the early 2000’s Patriot again rebranded the ShBoom and called the design IGNITE.  Patriot no longer makes or sells processors, concentrating only on Intellectual Property (Patent licensing).

After designing the Sh-Boom, and the Novix series, Moore developed yet another processor in 1990 called the MuP21.  This was the beginning of a what would be a common thread in Moore’s designs.  MISC (Minimal Instruction Set Computer), which is essentially an even simpler RISC design, multiprocessor/multicore, and efficiency have become the hallmarks of his designs.  The MuP21 was a 21 bit processor with only 24 instructions. At 20MHz performance was 80 MIPS as it could fetch four 5-bit instructions in a 20 bit word.  It was manufactured in a 40 pin DIP on a 1.2 micron process with 7000 transistors.

iTvcIn 1993 Moore designed the F21, again a 21 bit CPU based on the MuP21, designed to run Forth, and including 27 instructions.  It was fab’d by Mosis on a 0.8u process.  The F21 microprocessor contains a Stack Machine CPU (with a pair of stacks like the NC4000), a video i/o coprocessor, an analog i/o coprocessor, a serial network i/o coprocessor, an parallel port, a real time clock, some on chip ROM  and an external memory interface. Performance was 500 MIPS (this was an asynchronous design, so ‘clock speed’ is a bit of a misnomer) and transistor count had risen to about 15,000.  The F21 was made up through 1998, however the design continued to evolve.  A version of the F21 was developed called the i21, originally for Chuck Moore’s iTV Corporation, which was one of the very first set top Internet appliance companies.  It integrated additional featured such as infrared remote interface, modem DMA interface and a keyboard DMA interface. The F21 scaled well, and was tiny, remember, only 15,000 transistors, which at 0.18u takes up a VERY small die, and allowed performance to hit 2400MIPS @ 1.8V.  One could put a very large amount of these on a single die…..

Read More »

Posted in:
Research

February 21st, 2013 ~ by admin

Charles Moore: From FORTH to Stack Processors and Beyond

NRAO Radio Telescope

NRAO Radio Telescope

There are many greats of the CPU industry, some, such as Federico Faggin (designer of the 4004 and worked on the 8008, then founded Zilog) are fairly well known.  Others include Gelsinger and Meyer (of x86 fame) perhaps even Gordon Moore, of which a  ‘law’ is named.  Chuck Peddle and Bill Mensch designed the ubiquitous 6502 processor, but there were more, many more. Engineers whose names have been oft forgotten, but whose work has not.  The 1970’s and 80’s were the fast and the furious of processor designs.  Some designs were developed, sold, or canceled in weeks, months; years were not a period of time that was available to these designers, for in a year, a new technology would dictate a new design.

One of these designers is Charles H. Moore. (aka Chuck Moore).  Chuck is perhaps best known for inventing the FORTH programming language in 1968, originally to control telescopes.  It was a stack based language, and lended itself well to small microcomputers and microcontrollers.  Some microcontrollers even embedded a FORTH kernel in ROM.  It was also designed to be able to be ported to different architectures easily.  FORTH continues to be used today for a variety of applications.  However Chuck did not just invent a 1970’s programming language.

Read More »

Posted in:
Research