Archive for February, 2016

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 13th, 2016 ~ by admin

RCA CDP1855: A Multiplier for the COSMAC

RCA CDP1855CE - 3.2MHz @ 5V

RCA CDP1855CE – 3.2MHz @ 5V

In the 1970’s MULT/DIV instructions were fairly uncommon to be implemented in hardware on a processor.  They were implemented in software (usually be the compiler, or hand coded) as a series of adds and subtracts/shifts.  In some cases dedicated hardware, usually through a series of bit slice processors, or ‘181s were added to handle MULT/DIV requirements.

In 1978 RCA announced the CDP1855 Programmable Multiplier/Divider for the 1802 COSMAC processor.  Sampling began in 1979, making this one of the earliest ‘math coprocessors’ of the time.  The 1855 was an 8×8 Multiplier/Divider, handling Multiplies with Addition/Shift Right Ops, and Division using Subtractions/Shift Left Ops.  It was, like the COSMAC, made in CMOS, and at 10V ran at 6.4MHz, allowing for a 8×8 MULT to finish in 2.8us.  The CDP1855 was also designed to be cascaded with up to 3 others, providing up to a 32×32 bit multiply, in around 12usec, astonishing speed at the time.  Even the slower CDP1855CE (using a 5V supply and clocked at 3.2usec) could accomplish a full 32×32 MULT in 24usec.  An AMD AM9511 (released a year earlier) can do a 32×32 fixed point multiply in 63usec (@ 3MHz).

Soviet Integral 588VR2A - CDP1855 'Analog' from 1991

Soviet Integral 588VR2A – CDP1855 ‘Analog’ from 1991

The CDP1855 was designed to interface directly with the 1802 processor, but could be used with any other 8-bit processor as well.  It was programmable, so the host processor only needed to load with the data to be multiplied/divided, the control values ot tell it what to do, and then wait for the results.

As was typical, the Soviets made an ‘analog’ of the CDP1855 called the 588VR2 and 588VR2A.  The 588VR2 was packaged in a 24-pin package vs the 28 pins of the CDP1855, so its certainly not directly compatible.  Soviet IC design houses were instructed and paid to design and make copies of Western devices, typically original ideas were discouraged.  This led to a lot of devices being made that were similar, but not the same as their Western counterparts, the design firm could make a somewhat original device, and then simply claim to the bureaucrats that it is an ‘analog’ to a certain Western design.  Thus the 588VR2 is ‘similar’ or an ‘analog’ to the 1855.

The CDP1855 continued to be made, and sold into the late 1990s, much like the 1802 processor it supported.


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.


Posted in:

February 3rd, 2016 ~ by admin

The End of the Omega

ST STi5500 - The Original 50MHz Transputer based Omega

ST STi5500 – The Original 50MHz Transputer based Omega

In January ST announced that they would be exiting the Digital Set Top Box (STB) market.  This is a market that they arguably led for the last 20 years, and one that really began with their Omega processor in 1997. The ST Omega processor line, beginning with the STi5500 powered set top boxes, for cable companies, satellite companies, and DVR’s as well as other TV connected devices.  Open up a satellite TV receiver from the last 20 years and you are very likely to find a STi Omega chipset.

The STi5500 was the beginning, and interestingly at its core was a ST20 processor, based on the Inmos Transputer (which ST now owned) from the late 1980’s.  The Transputer was meant to revolutionize computing, making processors so cheap, that they could be embedded into pretty much any other logic device, what today we call an SoC, but in 1985, was a novel idea.  At the time it didn’t really succeed, but ended up seeing its intended use 10+ years later in the Omega.  In the 1980s the Transputer saw speeds of up to 30MHz, int he STi5500 it ran at 50MHz with 2K of I-cache + 2K of Data Cache as well as 2K of SRAM that could be used as data cache.

ST STi5514 - Enhanced 180MHz Omega

ST STi5514 – Enhanced 180MHz Omega

In the early 2000s the Omega was upgraded to a faster ST20 core, eventually hitting 243MHz in the STi5100, now with the caches increased to 8K each, as well as 8K of SRAM.  This was getting to be the limit of the ST20 Transputer core.  ST needed a core that could support higher speeds running such things as Java and Windows CE amongst other things, as well as support the higher resolutions and audio quality requirements.

ST handled this is in two entirely different ways.  First they licensed the SH-4 32-bit RISC core from Hitachi, a rather surprising move but STBs was not a market Hitachi was in, so it was in both companies best interest.  ST also was working on their own new core to replace the ST20, and they had help, from a very surprising partner.

Read More »