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I had lunch with Jim last week to get a little color on the early days of the Virtuoso platform. As you probably know, those days were 25 years ago, as this year is the 25th anniversary of the Virtuoso environment.
But Jim went back even further. As you probably know, SDA, one of two parent companies that merged to create Cadence, was founded by Jim Solomon (the S of SDA) after he left National. At the time, Jim (Hogan) was also at National. Jim Solomon funded SDA partially by getting half a dozen companies to invest in return for access (you could do that back then), and National was one of the companies that took the bait. Jim managed that relationship for National.
For more details on the founding of SDA, see my interview with Jim Solomon, How Did Cadence Get To Be So Good At Analog?.
At the time National was using a lot of Daisy systems. Since Daisy built their own hardware (as did Valid, but unlike Mentor, which used Apollo workstations), it was expensive. SDA ran on Sun workstations, which were mass produced and so were a lot cheaper. Jim Hogan realized that he could basically buy a Sun workstation for the maintenance fees on a Daisy system and that alone justified the investment in SDA.
National acquired Fairchild, which had a very East Coast attitude, and were still using Vaxes with graphics terminals. Again, a graphics terminal wasn't much cheaper than a Sun workstation, and since Jim was given the task of rationalizing the hardware and methodologies, the merged company standardized on SDA software running on Sun hardware.
The Virtuoso tool at its heart was a layout editor. What differentiated it from other layout editors such as Daisy Chipmaster (I think that was the name) was that it had extraction, LVS, DRC and back annotation onto the schematic integrated together. In fact the first implementation was done by James Spoto at Harris Semiconductor and was written entirely as an extension to the basic layout editor (which was designed for microwave in its first incarnation) and was written in SKILL. But this crude implementation took them ahead of Daisy, which at the time had taken over from Calma as the leader in polygon layout editors.
Somewhere around then Jim Hogan left National and joined SDA/Cadence. At this point the Virtuoso tool was up to version 2.5, still largely written in SKILL and fairly slow. Most of the SKILL was moved into C to create version 4. Nobody seems to know what happened to version 3, maybe it was like the '60s in San Francisco where they say that if you can remember them you weren't there. One big challenge was that most designers using the Virtuoso tool were doing analog and were happy with 2.5 and, to make it worse, like many major releases the first version had a lot of problems such as taking half an hour to read a design. For example, Toshiba stayed on 2.5 and an old version of Sun OS. When Cadence and Sun stopped support, they still didn't move, they just kept running the old hardware, five years behind the current releases of hardware, OS, and software. Analog designers are still a bit like that!
Jim worked with the sales team since they needed a lead customer, or the product would never improve. That lead customer turned out to be Timex, who were designing watch chips, of course. This was the first silicon on Virtuoso 4.0 done by Matt MacConnel and Craig Crump out of the Orlando office.
Trivia fact of the day: during the 9/11 attacks, a dad and his daughter escaped by using their Timex watches to light the way, containing those first chips designed on Virtuoso 4.0.
By the time 4.2 and 4.3 came along, the Virtuoso tool was solid. It combined the Composer schematic editor, Virtuoso layout editor, and Diva DRC/LVS and could back-annotate parasitics onto the schematics. It was way ahead of any other product on the market at that time and has continued to be the leader in both technology and market share to the present day.
Jim Hogan took on a whole range of roles at Cadence, including living in Japan for many months to sort out issues there, being one of the co-CTOs of Cadence (along with Ted Vucurevich and me), running all the AEs, and more. Eventually he left for Artisan and became an independent investor when he moved on from there after the ARM acquisition.
The page with details of Virtuoso's 25th anniversary is here.