[rescue] Rescued VAX 4500 question

[Brian Hechinger]

On Thu, Jun 13, 2002 at 11:09:35PM -0500, Scott Newell wrote:
> 
> Jeez, that sounds nothing at all like the systems I've seen.

from what i read later you are on much older slower systems.

> The XINU book mentions that the interrupt dispatcher prescales the 60Hz RTC
> rate down to 10Hz, because it can't keep up at 60Hz.  Considering the XINU
> is a pretty light OS, well, I assumed that it (they call it an LSI 11/2 ?)
> must be a pretty slow machine.  And that's all I'm going on...just a single
> excerpt from an old book  (I've run 68HC11 in embedded products,
> multitasking, with >50Hz tickers, so it really jumped out at me when I
> first read it.)
> 
> Now maybe what I'm calling an embedded LSI-11 system is really some
> seriously cut-down, bare-bones, low-end implementation?  When I think
> PDP-11, I think racks full of stuff, and that's a long way from what ran
> these little milling machines.

ahhhh, 11/2.  that's a different story. ;)

first LSI based machine.  not even remotely close to fast, maximum 32Kw ram (so
it is 64Kb) and no hope of ethernet, but disks are not out of line.

but since it's all qbus, it's pretty much a cpu swap up to something faster,
like a PDP-11/23.  which i have a spare CPU of floating around here somewhere
if you'd like.  i may even have some ram laying about as well.

my PDP-11/23 came from a guy who did ALL his development (FORTRAN) on this one
machine.  way cool stuff.

-brian
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