Slashdot Mirror

IBM mainframes were commonly virtual machines. Unlike their predecessors, which had their instructions hard-wired into them, the System/360 and later boxes usually had some sort of "Initial MicroProgram Load" phase that kitted out the machine's NVRAM with the microcode that made them all run the common S/360 instruction set, regardless of underlying hardware, which could be quite radically different, depending on the make and model.

For System/360, only the Model 85 and Model 25 had microcode in RAM rather than ROM (the Model 75 and Model 91 didn't have any microcode, the instruction set was implemented in hardwired logic). The hardware was, as far as I know, primarily designed to implement the System/3x0 instruction set; different machines may have been friendly towards other instruction sets to different degrees (emulators existed for some 140x and 709x machines, but they only needed to run those instruction sets as well as the original machines, not as well as the S/3x0 instruction set ran). Writable control store became common in System/370.

These days, I think the commonly-used instructions are hardwired (and multi-operation instructions cracked into micro-ops, Pentium-Pro-and-successors-style, in the latest chips), and some of the more-complicated instructions may trap to "millicode", which is native machine code, perhaps with special access to machine-specific hardware. (Yes, it does sound a bit like PALcode.)

If you can muck up an old SGI, those are pretty neat, too

SGIs are also gorgeously good looking. A 16 CPU Origin 2000 went for £620 on last week; I have to say it was quite the temptation.

Stroller.

Yes but its not cool like an AlphaServer

Last I checked a Multia wasn't an Alpha Server

Yes but its not cool like an AlphaServer

Last I checked a Multia wasn't an Alpha Server

I was surprised at just how far companies like Kingston have to go to honor their lifetime warentee. I worked for SGI a couple of years ago and I was using a old beat up (8 years obsolete and it still performs decently!) Personal Iris 4D/35 when after a power failure it failed to boot complaining about bad memory. So I pull the thing apart and find that it has an enormous board with 16 SIMM-like slots. I pull out the offending module and notice 2 things:

1. It is obviously some sort of custom memory module unlike any I had ever seen before, and hasn't been manufactured in years and years.
2. It has a Kingston Memory sticker on the front.

So, I decide to see just how good the "lifetime warentee" is. Amazingly enough, they send me an RMA label right away and within days I have a brand new memory module and the system is back up and working perfectly! I was truely amazed that they were still willing to honor their agreement (I've had many bad "lifetime" warentees before where the "lifetime" is defined as 1 year or other BS) without complaint or hesitation.

Going back to SGI, eh? Iris Indigo

If you are looking to stick a mini-itx board in something, you can use almost anything as a case. I like the classics, and breathed new life into a dead SGI O2 workstation. (Not pics my box, but a nice set of pictures of the space you have to work with) Add a wireless mouse and keyboard, mix in a nice LCD display, and it makes for a lovely terminal.

The look on my uncle's face when they saw the 'email and web browsing' computer sitting on their mom's desk was priceless. Such awe for a meager fan less 533mhz Eden board - due only to the case. (grin) A gift that keeps on giving.

they're very expensive and less powerfull than my $1500 pc at home, but look at al the cool stuff you can make of it:

SGI casemods

espresso, anyone ?

Thanks for the link. I'd actually already checked out that site. It was pretty outdated, especially compared to modern PC specs and Linux' capabilities.

This site also had some interesting descriptions of the specific hardware, but what I found missing from most sites was "what do I really need, and what do I get for upgrading" especially as it relates to current PCs and graphics cards.

Thanks though!

--D

I've long believed it needs to be removed from the nuts-n-bolts for something smaller and faster. Let X11 support be a strap-on application for those who need it, like it is for OSX.

Please make up your minds, people. X11 was certainly fast enough on this speedy beast, and hasn't inherently gotten slower since. If you want something *smaller* than X11 to drive graphics, you'd better be prepared to write lots of code to handle niggling details like window displaying - in the graphics libraries. Ick. Projects like Berlin try to add *more* features to the windowing system that X11 doesn't have, which isn't necessarily bad. But it's not going to be *less* bloated than X11 is now.

But "old" and "bloated" is going to be a contradiction when one considers the advances in hardware over the 10+ years I've been using X11.

NeXT's workstation slabs worked kinda along these lines. Although the CPU was not attached to the case, the case worked like a heat sink. It had fins running along the underside of the case from front to back with a fan mounted at the front, pushing air out the back along the vertical slits. Here's a site (lower right-hand corner) with a picture.