Re: [N8VEM-S100:559] Best place to start building S100 computer?

[Jack Rubin <jack....@ameritech.net>]

That's why I've been doubling up on many of the N8VEM boards - one to build with 
regulators for vintage systems and one to build without regulators for a modern 
"reference system" for software testing and reliability. :>)

Jack



----- Original Message ----
> From: John Monahan <mon...@vitasoft.org>
> To: n8vem...@googlegroups.com
> Sent: Wed, December 21, 2011 12:11:45 PM
> Subject: RE: [N8VEM-S100:559] Best place to start building S100 computer?
> 
> The only problem with that Jack is you have to remove/bypass regulators  on
> every board. A real pain if you are switching old/new S-100 boards in  out
> and essentially out of the question if you have as well an old IMSAI  like
> box. If you are doing this, watch out for Zenier diodes on some  boards.
> Honestly the modern switching supplies are easier and don't provide  any home
> heating!
> John
> 
> 
> John Monahan Ph.D
> mon...@vitasoft.org
> 
> -----Original  Message-----
> From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com]  On
> Behalf Of Jack Rubin
> Sent: Wednesday, December 21, 2011 4:51 AM
> To: n8vem...@googlegroups.com
> Subject:  RE: [N8VEM-S100:558] Best place to start building S100 computer?
> 
> Why  fight to drive uphill to just heat the room? Just eliminate the  78xx
> regulators and run 5 and 12 volts on the rails! That's what Godbout  and
> Morrow did at the end - it's certified vintage and it's smart. 
> 
> Jack
> 
> > -----Original Message-----
> > From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com]
> >  On Behalf Of Mike
> > Sent: Wednesday, December 21, 2011 12:11 AM
> >  To: n8vem...@googlegroups.com
> >  Subject: Re: [N8VEM-S100:557] Best place to start building S100 
> >  computer?
> > 
> > On 12/20/2011 02:49 PM, W3DRK wrote:
> >  [clip]
> > >
> > > I'd like to start by collecting the basic  "core" parts such as a
> > power
> > > supply and motherboard and  build up from there.
> > >
> > > Fortunatly I am friends with  someone in the custom transformer field 
> > > so getting a decent  transformed sized just for this purpose should 
> > > be pretty strait  forward, and perhaps even less expensive then using 
> > > 2
> >  or
> > > 3 seperate SMPS units.  I already have heavy heatsink  mounted 
> > > rectifier diodes, filter caps, etc so that helps  too.
> > >
> > [clip]
> > > Thanks!
> > > Dieter  Kedrowitsch - W3DRK
> > 
> > Hi Dieter,
> > 
> > I'd agree with  the others regarding the use of a switching power 
> > supply.
> > I got  a 7.5V @42A supply from eBay that has a little bit of voltage 
> >  adjustment, but I'm leaving it at 7.5V so the 7805s will run a little 
> >  cooler.
> > 
> > I also got, from eBay, a couple of 12V @5A  switchers  to run the +/- 
> > 16V rails, they will adjust to about  14.5V which will be fine.
> > 
> > All together I don't think I spent  more than about $80 on the power 
> > supplies.
> > 
> > PS. Sorry  I've been slacking on the 68K work, guys, I've been just up 
> > to my neck,  it's getting closer to the front burner however.
> > 
> > Mike  Sharkey
> > http://8bit.zapto.org
> > -----
> > No virus found in  this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.1890 / Virus  Database: 2109/4693 - Release Date:
> > 12/20/11
> 
> 
>