Re: Using different storage key's
- From: m42tom-ibmmain@xxxxxxxxxxxx (Tom Marchant)
- Date: 30 Jun 2006 13:36:53 -0700
On Fri, 30 Jun 2006 13:06:17 -0600, Anne & Lynn Wheeler <lynn@xxxxxxxxxx>
wrote:
Tom Marchant wrote:Snip!
The Amdahl 580 series had the same sort of thing, but they called it
macrocode. It made it easy to implement new instructions. An
interrupt would cause a switch to "System state" and macrocode would
decide what to do with it. Macrocode, combined with increased
addressability and some novel channel architecture made it relatively
simple to implement XA.
MDF was implemented with a lot of special registers and macrocode to
perform the necessary setup.
Too bad I didn't keep my copy of the ALTA POO when I left the company...
It was also used to implement the original hypervisor ... which IBM
eventually had to respond to with PR/SM in 3090.
We used to talk about it at the monthly meetings at SLAC ... possibly
even talked about it before it was even announced. I also had discussed
some of my experiences having worked on ECPS for 138/148 ... a couple of
old ECPS postings
http://www.garlic.com/~lynn/94.html#21 370 ECPS VM microcode assist
http://www.garlic.com/~lynn/94.html#27 370 ECPS VM microcode assist
http://www.garlic.com/~lynn/94.html#28 370 ECPS VM microcode assist
I have some vague recollection of one of the people who had done the
hypervisor implementation saying that they had hoped for better thruput
improvement based on my comments regarding ECPS.
various collecting postings discussing various microcode aspects (mostly
360 or 370)
As I recall, far from running a 370 subset, it could use the full
580 instruction set, which was a (minor) superset of 370. There may
have been a restriction of not supporting code that did store in
instruction stream, though.
In addition to another set of GPRs that became active when running
in system state, there was an additional level of memory mapping,
supported by special translation registers, as well as special
support for I/O.
Tom Marchant
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to listserv@xxxxxxxxxxx with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
.
- Prev by Date: UA90255 now available to ENABLE NJE OVER TCP/IP IN JES2 Z/OS 1.7
- Next by Date: Re: Character set conversoin headaches
- Previous by thread: Re: Using different storage key's
- Next by thread: Re: Extra/Attachmate Profiles
- Index(es):
Relevant Pages
|
