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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VLSI VY12338 THING UA-JET238-01 – Made in 1997

VLSI was started back in 1979 by several former Fairchild employees, 2 of which had previously founded Synertek, a connection that becomes important later on.  VLSI is best known for being a contract deign/fab services company.  They excelled at custom, and semi-custom designs for a wide range of customers, as well as acting as a foundry for customers own designs.  They became best known for their part in the development and success of the ARM processor back in the late 1980’s with ACORN.  They manufactured, as well as marketed and sold, several versions of the ARM processor, one of the few processors they actually sold themselves.  They also made a 6502 used by Apple and 65C816 (CMOS 16-bit 6502).  The 6502 was also a processor that Synertek had made back before Dan Floyd, and Gunnar Wetlesen left Synertek to start VLSI.

VLSI went on to fab processors for some of the biggest companies of the 1980’s.  The made the processor for several Honeywell BULL mainframes, built the processor for the HP A990 computer, and made dozens of chips for SGI and WANG.  VLSI also enjoyed wide success in the early 1990’s making chipsets for 486 processors, before Intel began to offer chipsets on their own in the Pentium era.

Unfortunately like LSI, most of VLSI’s designs are relatively unknown to all but them and their customer.  Marking on the chips rarely provide information on who it was made for, and even less on what exactly it does.  The above chip, marked “VY12338 THING UA-JET238-01” seems to be names as an answer to the question “What do we call this thing?”  Certainly seems to be a bit of humor on the part of some engineer.

VLSI was bought by Philips (now NXP) in 1999 so the THING may forever remain an unknown thing.

I’ve posted a fair amount about ARM processors, as today, they are in about everything. That was not always the case. ARM began with a small British company called Acorn Computers, who made various computers such as the BBC Micro (6502 based). They began developing a RISC processor in 1983 with their silicon partner VLSI. We recently received a few early versions of the ARM so here they are, with a brief history.

VLSI VL2333-QC 8MHz ARM1 CPU circa 1988

By 1985 they had the first working silicon of the ARM1 processor, a full 32bit design. It had around 25,000 transistors (compared with the earlier Motorola 68000 which had 70,000) so was relatively cheaper.

VLSI VL86C010-16PSQC 16MHz ARM2 CPU circa 1990 - Prototype

The next year the released the ARM2 processor, which added a hardware multiply instruction and ran at 8MHz. It had around 30,000 transistors.

VLSI VY86C610C 30MHz ARM610 CPU circa 1994

In 1994 the ARM6 was released with higher clocks (up to 60MHz) and more features.  The rest as we say is history, with many many varieties of cores available, at speeds over 1GHz, but STILL very small footprints. The ARM cores are licenses to hundreds of companies worldwide, and used in millions of devices, and it all began almost 30 years ago.