Henk Tobbe wrote:

> Recently I moved from the Netherlands to Australia (NSW) and left the
> ISDN stuff that served the household behind  :-(  because ISDN in
> Australia is prohibitively expensive.

  AFAIK, *all* serious telecoms in this country are prohibitively
expensive.  Internet inclusive.  How much did you pay per local call in
the Netherlands?  You presumably know how much here, about 27 cents
(corresp. to about 14 cents US).  *In addition to* line rental domestic
= $120 per year, business is double that.

> For our new house I was thinking of buying a cheap one line - 4
> extension homephone exchange.

  This is called a "small business" system.  What else?  Same function,
doesn't matter where you use it.  You are generally looking at (a guess)
$1000 (AUS).  May be less, I haven't looked in the last ten years!
Major manufacturer = NEC.

  Mind you, I always have my eye out for a second-hand one to use in my
home.  Trouble is, many are Aust. Telecom "Commander" systems (one is a
Siemens) which use two pairs, proprietary phones and are incompatible
with Fax and modems :-(

> However.... as dutch electronics magazine adds have these on offer for
> competitive prices (US$ 75 - 250 equivalent) I have not seen a single
> ad for this stuff "down under" yet.

  You mean a PABX?  Not a PAX/ Intercom?  Certification here is pretty
strict (or is that, ... expensive?).

> So the idea of building my own - based on a PIC and some additional
> hardware from my junk box - came to mind.

  And connect it as a PABX (i.e., "Branch" exchange, to the outside
line)?

>  Before embarking on this project I would like to have two questions
> answered - hopefully by other subscribers.

> 1.  Why is it that there are no home phone exchanges on the NSW
> market.

  As explained, PABXs, even minis, too expensive.  Home === Business.

> 2.  Has anyone done such a project or know about a site or source for
> examples, further information?

  The mags have published a couple of crude PAXs.  Crude = unbalanced,
not fully switched, single bridge (and again, I say "bridge" very
approximately!).
--
  Cheers,
        Paul B.