Three questions

[Mike Bilow]

Mark Glassberg wrote in a message to Mike Bilow:

 MG> A friend uses an IBM AS400 in his business, which he is not
 MG> satisfied with. While listening to his complaints recently,
 MG> I suggested he look into linux. He explained that there are
 MG> a number of impediments to such a move.  First, he says the
 MG> AS400 would have to be sold because it can only run under
 MG> IBM's proprietary operating system.  So, my first question
 MG> is, is this correct? 

The AS/400 is actually based on a PowerPC processor core, often in
multiprocessor configurations.  It is probably possible, in theory, for someone
to port Linux over to it, but this would represent considerable work and would
require knowledge about proprietary internals.  The current operating system
for it from IBM, called "OS/400," does have a certain degree of POSIX
compliance.

It is also possible to buy a special configuration of the AS/400 processor core
which is capable of emulating the old IBM System/36 minicomputers.

You should understand that the AS/400 is a very powerful computer for certain
types of operations, uses a 64-bit processor subsystem, and comes in a number
of different "performance groups."  Machines in the high-end performance groups
can blow the doors off of any PC for transaction processing, regardless of the
operating system.  AS/400 computers can also be timeshared for hundreds of
users with dumb terminals.

 MG> Then he explains that the reason he uses this machine is in
 MG> order to run a proprietary IBM relational data base
 MG> management system called DB2, and final- ly he says that he
 MG> uses software written in RPG which utilizes DB2.  So my next
 MG> two questions are:  a) Is there a linux or unix package
 MG> which could re- place DB2, and b) Is it possible to run
 MG> software written in RPG on a linux system?

DB2 is the flagship of the IBM "Software Servers," sometimes known as the
"Project Eagle Suite."  DB2 is available on nearly any platform except Linux,
including OS/390 (formerly MVS for System/390 mainframes), DOS/VSE (the older
mainframe operating system), NetWare, OS/2, Windows NT, and several Unixes
including AIX and SunOS/Solaris.

If the situation is such that your friend is running a large volume of
transactions and needs to keep to a tight schedule in real time, then the
AS/400 represents money well spent.  If, on the other hand, the goal is a
minimum cost system which is running with a very light load, then the OS/2
version of DB2 will run on the leanest hardware.  You could run OS/2 on about
the same machine as Linux, such as an old 386DX, although I would not recomend
trying to use DB2 on OS/2 in less than 32 MB RAM.

 MG> Any assistance will be greatly appreciated.

Have fun.
 
-- Mike