S/36 in Milwalkee

Paul Berger phb.hfx at gmail.com
Sat Nov 5 17:40:56 CDT 2016

On 2016-11-05 4:07 PM, Al Kossow wrote:
> On 11/5/16 11:24 AM, Jason T wrote:
>> I'm guessing
>> it's far more due to IBM having never released anything close to
>> technical documentation on the architecture
> S/32 - 36 are fairly well documented. It's just non-trivial to do the work
> and would require someone to reverse-engineer with a machine next to them.
> S34 would probably be easier though since it only has one processor and
> didn't have quite as much LSI in it.
> If you need some place to dump the resulting scans and disk images, I can
> put them on bitsavers. I still have several boxes of S/36 documentation in
> the backlog.
The architecture of both the S/34 and S/36 is very similar and both of 
teem include two processors the CSP and MSP.  The CSP handled most of 
the I/O operations as well as getting the system off the ground while 
the MSP processor executed the user programs.  Even the S/32 is very 
similar.  The S/32 was a single user machine with up to 64K of memory, a 
10MB disk and either a dot matrix or belt printer built in.  The S/34 
added more memory and multi user capability. S/36 again increased the 
maximum memory, had faster processors, a much improved user interface on 
the OS (SSP) and added one more instruction.  The MSP memory in the S/34 
and S/36  was divided into 64K segments and no program object could be 
larger than 64K.  The hardware itself is pretty unspectacular, the main 
reason for the popularity of S/36 was the availability of software and  
the ease of use of the system.  They where commonly found in small 
businesses that had no DP staff, at a  lot of my S/36 customers,  the 
person looking after the S/36 was the controller.  The user interface on 
the AS/400 was largely based on the S/36 SSP.


More information about the cctech mailing list