Re: [Bulk] CISC (ugh!) question

[Jim Oberholtzer <midrangel@xxxxxxxxxx>]

The secret can be found in the number of slots.  There were only two 
memory card slots on the B50.  The B60 had four and the B70 had five.

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


On 9/29/2011 5:47 PM, Mark S. Waterbury wrote:
> John:
>
> The correct answer may be found in the AS/400 CISC System Builder,
> available here:
>
>       http://www.redbooks.ibm.com/redpapers/pdfs/redp0042.pdf
>
> See Chapter 6.    And, yes, apparently 48 MB was the maximum main
> storage size for the B50 (no explanation as to why.)
>
> Hope that helps (for what it's worth...)
>
> Mark S. Waterbury
>
>   >  On 9/29/2011 5:27 PM, John McKee wrote:
> > >     A few weeks ago, I saw something on the list about how a modern system (can't recall if the system referred to was a 270 or whatever).  Just remember that "the doctor" described the possible memory expansion for it.  And that expansion was not "official" from IBM as I recall.
> > >
> > >  Which brought this nagging question to mind.  There is no practical value to any answer - except pure unrelenting curiosity.  I worked with a B50.  It was purchased with 24M of RAM.  Prior to my arrival, a deal was made to swap the genuine IBM memory for 48M of IPL memory.  That system was loaded down beyond belief.
> > >
> > >  I was told that 48M was the absolute maximum memory that the B50 could address.
> > >
> > >  This was obviously way before any customer oriented maintenance on a RISC system.
> > >
> > >  Was 48M the absolute maximum memory that the old beast could support?
> > >
> > >  My assumption, based on tremendous change in nearly 20 years is that 48M was indeed the maximum.  But, why 48?  Not a power of 2.
> > >
> > >
> > >  John McKee
> --