January 11, 2012

The personal computer you've never heard of

I was watching Dan Ingalls' Seven (give or take) Smalltalk Implementations talk given at Stanford in 2005 on YouTube, and around the 43 minute mark Ingalls talked about something I consider shocking:

In 1978*, a year after the introduction of the Apple II, Xerox PARC built a portable computer with a 7 inch, 640 by 480 resolution bit-mapped, touch-screen display based around a commonly available 1 MHz, 16-bit microprocessor with 128 KiB** of memory running Smalltalk-76. The computer was called the NoteTaker.

The NoteTaker ran Smalltalk as fast as the Alto (the Smalltalk-76 VM (6 KiB) actually executed bytecode twice as fast on the 8086 as on the Alto, but the memory bus was much slower, making interactive performance feel similar).

I always thought the 8086 was extremely underpowered and good only for DOS and terminals. In hindsight, it's mind-boggling how long it took x86 PCs to catch up with the Macintoshes and Amigas of the 1980s.

* Note that Wikipedia and other sources give the NoteTaker's date as 1976, but this is likely the date when design started, as the 8086 design also just started in 1976 and the processor did not ship until 1978. The NoteTaker manual is also dated December, 1978.

** The NoteTaker manual specs the machine at 256 KiB of memory.

*** The current Wikipedia article about NoteTaker claims this computer would have cost more than $50,000 if sold commercially (presumably in 1978 dollars). Assume that the CRT, floppy disk, power supply, keyboard and mouse cost $2,000 (a whole Apple II system with 4 KiB memory retailed for $1,298.00 in 1977). The 8086 originally wholesaled for $360. According to the NoteTaker manual, the NoteTaker had a second 8086 which acted as an I/O processor but was "also available for general purpose computing tasks." It would have been entirely possible to replace the I/O processor with a much cheaper CPU. Looking again at Apple's price list, a 48 KiB Apple II board retailed for $1,938, while a bare-bones 4 KiB one sold for $598, which gives $31 per KiB. So 128 KiB would retail for $3,900 and 256 KiB would retail for $7,800. It certainly would have been possible to produce and maybe even sell the NoteTaker with 256 KiB of memory for less than $15,000. Note that a few years later, Kim McCall and Larry Tessler made a subset of Smalltalk-76 that ran in 64 KiB of memory, but with the full system image only about 8 KiB of memory was available for user programs.

**** The NoteTaker also came with an Ethernet interface.

PS - While researching this article, I also stumbled on another PC you've probably never heard of. The Kenbak-1, similar in operation and capabilities to the MITS Altair 8800 (both came with lights, toggle switches, and 256 bytes of memory), was sold via advertisements in Scientific American for $750 in 1971, four years before the Altair.


Vladimir Sedach said...

Another computer I came across that might be interesting: http://en.wikipedia.org/wiki/Datapoint_2200

Anonymous said...

The first thing I thought when I saw the image was that it looked strangely similar to an Osborne 1. I wonder if this is what inspired Adam Osborne's design.

Just found your blog a few weeks ago, and am enjoying the backlog. Keep it up!