For years, I did not found how to read easily this forum.
Now, I found it is only to double-click the headline of the theme.
A new pretty window starts up, and you can read all of them without
magnifying glass.
as an addition to Konrad's comment, you can also read these newsgroups
from other providers, there are many of them, some change a nominal
sum per year or for nGBytes of data, for these text-only newsgroups
that could be several years worth.
There are also many more groups than the 3 Visio groups carried by the
Communities website
microsoft.public.cn.visio
microsoft.public.de.german.visio
microsoft.public.es.visio
microsoft.public.fr.visio
microsoft.public.jp.officexp.visio
microsoft.public.jp.officexp.visio.developer
microsoft.public.jp.officexp.visio.setup
microsoft.public.kr.visio.qna
microsoft.public.nl.office.visio
microsoft.public.visio
microsoft.public.visio.2002beta
microsoft.public.visio.beta
microsoft.public.visio.bldg_design_facmgmt
microsoft.public.visio.createshapes
microsoft.public.visio.database
microsoft.public.visio.database.modeling
microsoft.public.visio.developer
microsoft.public.visio.developer.diagrams
microsoft.public.visio.developer.layout-routing
microsoft.public.visio.developer.shapesheet
microsoft.public.visio.developer.vba
microsoft.public.visio.developer.vc
microsoft.public.visio.feedback
microsoft.public.visio.filters
microsoft.public.visio.general
microsoft.public.visio.installation
microsoft.public.visio.networkdesign.documentation
microsoft.public.visio.printing
microsoft.public.visio.productnews
microsoft.public.visio.software.modeling
microsoft.public.visio.troubleshoot
microsoft.public.visio.viewer
microsoft.public.visio.viewer.developer
microsoft.public.visio.wizards
though some of these are now defunct.