Editing IBM System/36 (section)

===AS/400-based backports===
The ''System/36 Environment'' of [[IBM i]] (previously OS/400) is a feature which provides a number of SSP utilities, as well as RPG II and OCL support. It does not implement binary compatibility with the System/36 - instead it allows programmers to port System/36 applications to IBM i by recompiling the code on top of the System/36 Environment, generating programs which use the native IBM i APIs.

From V3R6 to V4R4, OS/400 was capable of running up to three instances of SSP inside virtual machines known as ''Advanced 36 Machines''. This relied on emulation of emulation of the MSP implemented by the OS/400 SLIC, and thus provided binary compatibility with SSP programs.<ref name="fortress-rochester">{{cite book|title=Fortress Rochester: the Inside Story of the IBM iSeries|author=Frank G. Soltis|isbn=978-1583040836|year=2001|publisher=System iNetwork|url=https://books.google.com/books?id=ypJmzqt7JdUC}}</ref>

[[File:IBM_AS400_model_150.jpg|thumb|AS/400 9401-150 (also known as "Advanced Entry")]]

====AS/Entry (9401)====

The AS/Entry was just a stripped-down AS/400, first model was based on a AS/400 9401-P03. The operating system was SSP Release 6.  This machine was offered c.1991 to target customers who had a S/36 and wanted to one day migrate to an AS/400, but did not want a large investment in an AS/400.  In this regard, the AS/Entry was a failure because IBM decided the machine's architecture was not economically feasible and the older model 5363 that the 9401 was based on was a much more reliable system.

The entry line was later upgraded to AS/400 9401-150 hardware.
[[File:IBM_AS-400_9402-400_and_IBM_5251.jpg|thumb|AS/400 9402-400 model with expansion module and terminal; 9402-436 were based on a 9402-400.]]

==== Advanced/36 (9402, 9406) ====
{{Main|IBM Advanced/36}}
In 1994, IBM released the AS/400 [[Advanced/36]]<ref>{{cite web|url=http://www-03.ibm.com/ibm/history/documents/pdf/as400.pdf|archive-url=https://web.archive.org/web/20060503190444/http://www-03.ibm.com/ibm/history/documents/pdf/as400.pdf|url-status=dead|archive-date=May 3, 2006|title=A Brief History of the IBM AS/400 and iSeries}}</ref>  with two models (9402-236 and 9402-436). Priced as low as $7995, it was a machine that allowed System/36 users to get faster and more modern hardware while "staying 36". Based on standard AS/400 hardware, the Advanced/36 could run SSP, the operating system of the System/36, alone, or within [[AS/400]]'s [[OS/400]] as a [[virtual machine]]<ref>{{cite web |url=http://www-01.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_sm/6/897/ENUS9402-436/index.html&lang=en&request_locale=en |title=9402-436 IBM AS/400 Advanced 36 Model 436 |website=IBM |archive-url=https://web.archive.org/web/20160812162901/http://www-01.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_sm/6/897/ENUS9402-436/index.html&lang=en&request_locale=en |archive-date=2016-08-12 |url-status=dead}}</ref> so that it could be upgraded to a full-blown AS/400 for just extra licensing costs. The A/36 was packaged in a black enclosure which was slightly larger than a common PC cabinet.

The Advanced/36 bought the world of System/36 and SSP about five more years in the marketplace, but by the end of the 20th century, the marketplace for the System/36 was almost unrecognizable. The IBM printers and displays that had completely dominated the marketplace in the 80s were replaced by a PC or a third-party monitor with an attached PC-type printer. [[Twinaxial]] cable had disappeared in favor of cheap adapters and [[Cat 5|standard telephone wire]]. The System/36 was eventually replaced by AS/400s at the high end and PCs at the low end. 

The Advanced line was later upgraded to AS/400 9406-170 hardware. By 2000, the Advanced/36 was withdrawn from marketing.