WordNet (r) 3.0 (2006):

steam-powered
    adj 1: powered by a steam engine; "a steam-powered locomotive"

The Jargon File (version 4.4.7, 29 Dec 2003):

steam-powered
 adj.

    Old-fashioned or underpowered; archaic. This term does not have a strong
    negative loading and may even be used semi-affectionately for something
    that clanks and wheezes a lot but hangs in there doing the job.


The Free On-line Dictionary of Computing (30 December 2018):

steam-powered

   Old-fashioned or underpowered; archaic.  This term does not
   have a strong negative loading and may even be used
   semi-affectionately for something that clanks and wheezes a
   lot but hangs in there doing the job.

   [Jargon File]