[Info-vax] OT: news from the trenches (re: Solaris)

[Bill Gunshannon]

In article <mdt965$4hp$1 at speranza.aioe.org>,
	glen herrmannsfeldt <gah at ugcs.caltech.edu> writes:
> lists at openmailbox.org wrote:
>> On 12 Mar 2015 17:44:41 -0400
>> Scott Dorsey via Info-vax <info-vax at rbnsn.com> wrote:
>  
> (snip) 
>>> They did in fact design a low-end 370 chip for personal computers, which
>>> was actually a 68k with different microcode to emulate a 370.  And they
>>> made the PC/370 with it.
>  
>>> They didn't get Gates to build DOS for the /370 because the whole point of
>>> running a /370 is to run existing code.  They already had DOS/370.
>  
>> Ok, let's not get too confusing for those not familiar. DOS/370 has no
>> relation to MS/DOS or IBM PC/DOS, preceding both by many years. Still in
>> production today btw as z/VSE http://www-03.ibm.com/systems/z/os/zvse/
> 
> I don't think there is DOS/370.  There is DOS/360, built for machines
> too small to run OS/360. It was supposed to only last until people would
> move up to OS/360. Later, there was DOS/VS for small 370's, and
> DOS/VSE in later years, leading to z/VSE. 

Not sure about this, unless there were different meanings to the term DOS.
I used DOS/E (DOS with special customer modifications, we were a very big
customer!) on the 4331 under VM370.  Did COBOL, Fortran, BASIC and 360
Assembler.

>  
>> I never saw an XT/370 so I don't know what they ran. Looking quickly over
>> the net it appears they didn't emulate the full instruction set. Do you
>> happen to know what they were actually capable of and used for? It seems
>> they could not boot or run any mainframe OS.
> 
> The XT/370 and AT/370 run VM/PC, a customized version of VM/370.
> The CP (virtual machine) part runs partly on the 370 and partly on
> the 8088 or 80286, communicating with interrupts and shared memory.
> I believe the CMS is the same as VM/SP's CMS. 

I never got my hands on one (although there is one on eBay right now
for a bit more than a grand.  Don't know what you would do with it
as it was an ISA card and even I have no ISA machines left.)  I always
thought the only thing the PC hardware provided was device access.
Terminal, Printer and Disks.

> 
> Original VM/370 CMS runs with 800 byte disk blocks, but later VM's
> allow for 1K, 2K or 4K disk blocks, much easier to support on a PC
> file system.
> 
> Also, the DAT (virtual address) system works completely different
> from real S/370 DAT.
> 
> But the P/370 does everything the way it is supposed to, for
> later implementations of S/370. There is microcode for XA/370 and,
> on P/390 (with more control store) ESA/390.
>  
>>> >Of course, a large corporation is prevented from going that way because
>>> >making an affordable 370 based computer is tantamount to cannibalasing
>>> >higher end sales. DEC also suffered that fate.
>  
>>> And it's a small market item too, really.  But the PC/370 was actually
>>> very cheap considering what it was and what you could do with it.
>  
>> Ditto for the P/390. For 30,000 bucks you could run a real development shop
>> with 30-50 guys. They actually ran honest to goodness copies of VM and
>> OS/390.
> 
> -- glen


bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>