The VAX was a 32-bit CPU with a two stage pipeline which introduced modern demand paged virtual memory. It was also the dominant platform for C and Unix by the time the Bellmac-32 was released.
The Bellmac-32 was a 32-bit CPU with a two stage pipeline and demand paged virtual memory very like the VAX's, which ran C and Unix. It's no mystery where it was getting a lot of its inspiration. I think the article makes it sound like these features were more original than they were.
Where the Bellmac-32 was impressive is in their success in implementing the latest features in CMOS, when the VAX was languishing in the supermini world of discrete logic. Ultimately the Bellmax-32 was a step in the right direction, and the VAX line ended up adopting LSI too slowly and became obsolete.
It would have been good to know more about why the chip failed. There's a mention of NCR, who had their own NCR/32 chips, which leaned more to emulations of the System/370. So perhaps it was orders from management and not so much a technical failure.
Didn't Multics, Project Genie, and TENEX have demand paging long before the VAX?
On the other hand, during those years Intel has been extremely good at adopting very quickly any important innovation made by a competitor, while also succeeding to obtain better manufacturing yields, so that they were able to have greater profits, even with cheaper products.
Bellmac-32 has not been important commercially, but without it a product like Intel 80386 would have appeared only some years later.
With 80386, Intel has switched their production of CPUs from NMOS to CMOS, like also Motorola had done one year earlier with 68020. Both Intel and Motorola have drawn heavily from the experience gained by the industry with Bellmac-32.
That's being polite. Attributing the chip's failure to AT&T buying NCR is ridiculous; that happened in 1991.
Here's a rundown of what actually happened:
* After the divestiture, AT&T from 1984 is finally allowed to build and sell computers. (This is also why Unix was not a commercial product from AT&T until then.) Everyone, in and outside AT&T, thinks Ma Bell is immediately going to be an IBM-level player, armed with Bell Labs research and Western Electric engineering. One of many, many such articles that conveys what everyone then expects/anticipates/fears: <https://archive.org/details/microsystems_84_06/page/n121/mod...> If there is anyone that can turn Unix into the robust mainstream operating system (a real market opportunity, given that IBM is still playing with the toy DOS, and DEC and other minicomputer companies are still in denial about the PC's potential), it's AT&T.
* AT&T immediately rolls out a series of superminicomputers (the 3B series) based on existing products Western Digital has made for years for AT&T use (and using the Bellmarc CPU) and, at at the lower end, the 6300 (Olivetti-built PC clone) and UNIX PC (Convergent-built Unix workstation). All are gigantic duds because, despite superb engineering and field-tested products, AT&T has never had to compete with anyone to sell anything before.
* After further fumbling, AT&T buys NCR to jumpstart itself into the industry. It gives up five years later and NCR becomes independent again.
* The end.
>This is such an uplifting story until you think about how the 8086 is just about to wipe it off of the map.
People today have this idea that Intel was this dominant semiconductor company in the 1980s, and that's why IBM chose it as the CPU supplier for the PC. Not at all. Intel was then no more than one of many competing vendors, with nothing in particular differentiating it from Motorola, Zilog, MOS, Western Digital, Fairchild, etc.
The 8088's chief virtue was that it was readily available at a reasonable price; had the PC launched a little later IBM probably would have gone with the 68000, which Intel engineers agreed with everyone else was far superior to the 8086/8088 and 80286. Binary compatibility with them was not even in the initial plan for the 80386, so loathed by everyone (including, again, Intel's own people) was their segmented memory model (and things like the broken A20 line); only during its design, as the PC installed base grew like crazy, did Intel realize that customers wanted to keep running their software. That's why 80386 supports both segmented memory (for backward compatibility with the virtual 8086) and flat. And that flat memory model wasn't put in for OS/2, or Windows NT; it was put in for Unix.
That, and it had a compatible suite of peripheral chips, while the M68K didn't... Something I vaguely recall an Intel FAE gloating about soon after: "And we're going to keep it that way."
And it was the only processor I ever used that had a STRCPY opcode.
whats wrong with rep movsb?
It shifts all bits except for the sign bit, leaving it unchanged.
I have read many ISA's manuals and not seen this elsewhere. Most ISAs don't have separate arithmetic and logic left shift instructions. On M68K, which does, the difference between `ASL` and `LSL' is only that the former sets the Overflow flag if any of the bits shifted out is different from the resulting sign bit whereas the latter clears it.
macshome•11h ago
We really could use a place like that today.
em3rgent0rdr•6h ago
jll29•3h ago
Are there still regularly ground-breaking innovations (which ones e.g. in the last decade) coming out of the same lab today, whatever its owner or name?