Re:Emulating the AT&T 3B2 Computer
by flyinghamster on Wednesday May 23, 2018 @08:16AM
(#17133468)
I learned C on a 3B2, and for a while had access to a 3B20S at UIUC. You were right about the 3B20; UIUC had a pair of them that were originally called "shark" and "tornado", but were quickly nicknamed "snail" and "turtle" in honor of their performance. They were the size of refrigerators, and, IIRC, they were roughly equivalent to a VAX 750 (maybe a 780 at best).
To the best of my knowledge, the 3B20D, a dual-processor fault-tolerant system running a UNIX variant called DMERT, was only used in the #5 ESS telephone switch - and was eventually replaced by an emulator running on a Sun system.
Real 3B20/3B21's live on - as far as I know, the emulator was only used with the 5ESS VCDX (very compact digital exchange) - essentially a baby 5E that lives in a single rack.
(I've seen a 3B21 living in a real running 5E within the last three years)
There was a time "PC" stood for "personal computer", not "poorly architected computer with off-the-shelf parts and the cheapest CPU that could do the job", also known as IBM PC.
May the one that never had to deal with the A20 line or ask the keyboard controller for the favor of resetting the system throw the first stone.
Interesting. I had a Unix PC - the 7300.
When the mother board went bad AT&T sent a technician to my house to diagnose and replace it. For free.
Those were the old days of the lingering legacy of the way Bell did things.
The 3B1 AKA "UNIX PC" AKA "PC 7300" wasn't even Intel inside, it was Motorola 680x0. The true 3Bs (3B2/3B5/3B20) had WECO processors. (The first UNIX machine I used daily was a 3B20, in fact -- dog slow compared to the 680x0-based Sun 2s and 3s the cool kids got to use.)
The actual first UNIX PC (Intel processor) was the 6300 series, which were rebadged Olivettis. I ported a product line to the 6300 Plus, which at least had extended memory capability.