What's Your Favorite Processor on an FPGA?

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Have you ever worked with PCI-X?

I looked at a trace on a board at work. I was surprised - the writes were fast(ish) - about 100 ns was the smallest gap I saw between writes. The reads were slower. I didn't see reads closer together than about 2us.

This seems consistent with Larkin's measurements.

I'm still surprised though - 2 us is 20000 bit times on a 4 lane gen 1. Ok, it's only 16000 bit times before the 8B10B coding.

Maybe the switch is configured for store-and-forward rather than cut through, or something equally silly.

Regards, Allan

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As I recall, Unix and C were invented for the PDP11. As was Arpanet and the Internet. The PDP8 was the first "personal" computer, a computer that one person could buy and use all by himself, to automate a lab experiment or (in my case) simulate a steamship power train. That changed everything.

DECs RT11 OS was cloned to become CPM and Microsoft DOS, and lives on in the Windows command line.

What sort of computing system did you have in 1969? I had a PDP8 running Focal. What did you compute on in 1975? I had a PDP11 timeshare system with around 20 users.

Yup, PCIe is a pig! It's OK if you do DMA, but there's a heap of overhead building descriptor chains and fielding interrupts and stuff.

We're writing a Linux driver that lets us build descriptor chains and keep them, and reuse them as needed to repeat data transfers.

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No, but it's mostly dead, as PCI will soon be. Intel busses only last a few years each.

Bell Labs begat Unix, Ken Olson considered Unix "Snake Oil", didn't want anything to do with it.

-bill

But C and Unix were developed on the PDP11. Unix was "born" in 1970, on a PDP11/20. C is practically a PDP11 assembler.

KO made a lot of mistakes. But DECs architectures - PDP11, VAX, Alpha

- were great. And their operating systems were excellent. It's unfortunate that the winners were Microsoft and Intel.

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I had access to a PDP-8 in 1968. It ran Focal, but I programmed it in it's assembly language - Macro-8 - so I could set up and interrupt-driven progra m to monitor and document the chemical reaction I was researching.

I crunched the - more or less - raw numbers I got from the PDP-8 (it did se lective data averaging, but no more) on an IBM 7040/44. The PDP-8 numbers c ame out on paper tape, and went through a tape-to-Hollerith card converter before they got onto the IBM machine, which I programmed in Fortran, and go t to run as a single user machine for hours in the middle of the night - us ually 2:00am to 6:00am.

In my first industrial job, I had remote access to a Control Data machine r unning Fortran from an ASR-33 teletype terminal, but after that it was most ly DEC.

IRRR DEC failed because it didn't take personal computers seriously, rather like the railway companies who thought that they were in the railway busin ess when they were actually in the transportation business.

"Unfortunate"... KO made the humongously large mega-mistake of thinking there was no need for personal computers. But to his credit at that time computers were a bit larger than they are now. I think there was an ad of a beautiful woman in late 60's attire, perhaps rather elegant attire, but in a kitchen standing by a decwriter printing something. Not quite the ticket for storing recipes really.

Bill, on the other hand only made two mistakes. The first was thinking there would never be a need for more than 640 kB of computer memory. He got over that one pretty quickly since he wasn't designing hardware. But then he seems to have felt the Internet was not something important to a company writing computer OS. lol They saw the winds blowing a different direction and had to change their rigging all the way into court to justify why they were trying to kick other browsers off "their" computers.

Who else made fatal mistakes were made in the computer industry? Who at Osborn decided to promote the next generation before they were ready to ship and killed the current sales?

Why did the Alpha die? Was that more an issue of DEC going away? I don't recall who ended up with it. Was it Intel who let it die a lingering death?

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A *few* years? PCI has been around for 20 years!

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"transparent and

But mobos seldom have PCI slots any more. It's all PCIe now. And Thunderbolt will displace PCIe.

Motherboard slots are going away. Hell, motherboards are going away!

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CP/MDOS and never was. 'Control Program for Microcomputers' was written by Gary Kildall of Digital Research, Inc, and the later MP/M for multiple users was written for the 8080 from scratch. If that is a clone, so is every other OS.

Focal.

Did you own it?

I was still in high school in 1969, but a few students at the OTHER high school got some time on an IBM 360 that belonged to a local bank. I got my first computer in 1983, but I was troubleshooting & repairing the boards & software for a pair of Exorcisor bus based 'Metrodata' computers with six NTSC video outputs per system before I owned a computer. I had to repair them, since the OEM was out of business. A whopping 48 KB of RAM, and one 6800 MPU per system. One system had a SMS dual 8" floppy disk drive system, and they shared a single TI computer terminal. I wrote a terminal program for a Commodore 64 to replace the flaky TI, and added a menu system to reduce the 100+ commands the operator had to use to access different functions.

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It's alive & well in real servers for their RAID controllers and Ethernet or FC ports. I've never seen it used in a computer that sold for under $3K.

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case)

Focal.

No, but my employer bought it for me; cost $12,800 with 4k 12-bit words of core and a teletype, when you could but a Chevy for a tenth of that. It was mine in the sense that I was the main, usually only, user. A couple of years later, 1972 I think, we got one of the first PDP-11s. The PDP-11 was a wonderful architecture; it taught a lot of people, including me, how to think. x86 is a pig by comparison.

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combined.

Do current Intel chip sets support PCI-X? Or even PCI?

FPGA

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combined.

I think PCI was a *just* hard intermediary bus. All the other busses were tertiary to it, and went though it to get to the CPU.

I think PCIe is a hard intermediary bus too but it has it's own API practically, and I would call that pretty advanced. PCI-X is likely fully superseded by e, but elements of the original PCI paradigm decidedly must remain. PCI only had about 11 command codes.

HP

FPGA

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"transparent and

combined.

PCIe was desiged to be totally transparent against PCI. In theory, a BIOS or a driver can't tell if its talking to PCI or to PCIe. Thunderbolt is supposed to be the same. The only differences may be the hot-plug provisions.

Ah, it was HP who ended up with it. It lasted up until 2008, that's not too bad really.