Slashdot Mirror
Domain: 36bit.org
Stories and comments across the archive that link to 36bit.org.
Comments · 7
-
Re:iTunes isnt bloated... Its FUCKING FAT!
Wait a sec, I didn't realize there was a 36 bit version! I'll finally be able to play music on my "Non Existent Computer"!
Yeah, I'm still trying to get iTunes going on that old DEC! -
Re:All Well and good.
DEC never made mainframes
The DEC 36-bit systems were generally considered to be in competition with IBM's mainframes. DEC management did try to keep their perceived capaability just below the mainframe range to avoid provoking too strong a counter-attack from IBM - a strategy which many think was the beginning of the end for DEC.sPh
-
Re:31 bit architecture is very common
36 bit architectures are common. Of the mainframes I know of none are 31 bits...
36 bits was fairly common once upon a time, but no longer. Unisys still have a 36-bit series, but they're the last of the breed. See here.
Big scary IBM boxes are where you see the 31 bit weirdness.
-
Re:It's like English MeasurementsNo, I think it was a machine with a 36-bit word length. Now, 36 bits gives you a few different options for encoding text (note, I do not say ASCII
- SIXBIT. CAPITAL LETTERS ONLY (sorry
- 7-bit bytes. 5 bytes of 7 bits, giving 35 bits in total. The extra bit is either unused or can be used for a parity check. Allows full 7-bit ASCII.
- 8-bit bytes, using one of two methods:
- 4 bytes per word, 4 parity (or wasted, depending on implementation) bits.
- 4 and a half bytes per word. Or, rather, 9 bytes per double-word. This is more space-efficient.
- 9-bit bytes, 4 per word. Which is probably what the Honeywell did. The 9th bit is usually unused; I believe the Honeywell might have used it to support various functions.
36 bits used to be quite common in larger systems. See 36bit.org for more information on 36-bit computers.
The only ones I really know much about are the PDP-10s.
- SIXBIT. CAPITAL LETTERS ONLY (sorry
-
Re:64-bit isn't necessary - and Itanium may suck
from what I remember, the vax(yes, old, but still 36 bit) could handle a max of 64 Gb.
You're either trolling or misremembering or think "N-bit" refers to the size of physical addresses. VAXes were 32-bit processors; I no longer remember what the page table entries looked like, so I don't know how large the physical addresses were (but the VAX-11/780 was designed in an era when 4GB was a lot of disk space, so VAXes may well not have had even 32 bits of physical address).
32-bit machines can handle more than 4GB of physical memory. (In fact, the Pentium {Pro, II, III} and successor x86 processors can support 36-bit physical addresses.) They just can't handle it conveniently within a single process (no, segmentation on x86 doesn't make things better; it's not even necessary).
There are some people who might be delighted to see 36-bit desktop machines, but I doubt you're likely to see any new 36-bit general-purpose processors any time soon.
-
Re:PDP 10 hacks
Can you look up the part number (probably EK-something or DEC-10-something) and date? I've got the last version scanned on my web site, but it might be interesting to scan older ones for comparison.
-
Re:PDP-10 Project
I think it would only take one a couple of weeks to code up the PDP-10 architecture in VHDL and target an FPGA.
Not bloody likely. All of the software simulators required well over a year of development time. And you're not going to convince me that implementing the same complexity in hardware (even with an HDL) is *easier* than in software.If you want to give it a try, get the DECsystem-10/DECSYSTEM-20 Processor Reference Manual from my web site. Prove me wrong! Please!!