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RE: [N8VEM-S100:1391] S-100 Bus Terminator
Hi Tom! Thanks! Yes, I am trying to keep the S-100 boards following the
IEEE-696 board outline parameters. Also to fit the card ejectors the corner
holes have to go up above the edges of the card guides. It basically forces
the 10"x5.3" outline of S-100 boards. I've seen the "shorty" version of the
bus terminators before but they would have issues with the card ejectors. I
think we can use the extra space for prototyping area in case that's needed.
Thanks and have a nice day!
Andrew Lynch
> -----Original Message-----
> From: n8vem...@googlegroups.com [mailto:n8vem-
> s1...@googlegroups.com] On Behalf Of Tom Lafleur
> Sent: Sunday, February 10, 2013 12:10 PM
> To: n8vem...@googlegroups.com
> Subject: Re: [N8VEM-S100:1391] S-100 Bus Terminator
>
> also, if you do a 1/3 size card, add finger pull slots in the board to
help in
> removal....
>
> On Sun, Feb 10, 2013 at 8:10 AM, Tom Lafleur <laf...@lafleur.us> wrote:
> > Look good for me, I will take two of them....
> >
> > add proto space with regulator(s) would nice, but this is fine just
> > like it is...
> >
> > Can you make it a 1/3 size card to save cost??? not something one
> > would remove very often...
> >
> > tom...
> >
> >
> > On Sun, Feb 10, 2013 at 6:37 AM, Andrew Lynch <LYN...@yahoo.com>
> wrote:
> >> Hi Paul! Thanks! I like the idea of adding the prototyping area.
> >> That would be easy to do and generally useful. There is nothing
> >> wrong with being frugal!
> >>
> >>
> >>
> >> My intent with kicking off the S-100 bus terminator board design is
> >> to start the discussion on topic. Partially we can find out how much
> >> interest there is for a bus terminator and if the concept is viable.
> >> The board is really only useful for those with large legacy S-100
> >> backplanes. We do have an
> >> S-100 backplane but it is small and already includes bus termination
> >> circuitry.
> >>
> >>
> >>
> >> The S-100 bus terminator design is not final by any means and meant
> >> to be a starting point. I've made some updates to the S-100 bus
> >> terminator and attached are the new schematic and PCB layout files.
> >> Please review and send me any changes and/or corrections. As always,
> >> comments, questions, ideas, thoughts, are always welcome! This is a
> >> home brew computing community so peer to peer design and review is
> essential!
> >>
> >>
> >>
> >> I don't really like the probe and bus extension concept though since
> >> we already have an S-100 bus extender board which does those things
> >> and the design is pretty solid. In addition, I am working with Neil
> >> to make a basic boot board tool (64K SRAM, EPROM, UART, and parallel
> >> IO) called the S-100 64KIO board so that's redundant.
> >>
> >>
> >>
> >> I can send the S-100 64KIO board information to the group for review
> >> as well however noting that Neil is in the process of totally
redesigning the
> board.
> >> Please keep the comments and questions more at the concept level
> >> instead of the particular implementation. The design is likely going
> >> to change quite significantly if I understood Neil correctly.
> >>
> >>
> >>
> >> Great commentary and questions! Please let's discuss more. Thanks
> >> and have a nice day!
> >>
> >> Andrew Lynch
> >>
> >>
> >>
> >> From: n8vem...@googlegroups.com
> >> [mailto:n8vem...@googlegroups.com] On Behalf Of Paul Birkel
> >> Sent: Sunday, February 10, 2013 3:38 AM
> >> To: n8vem...@googlegroups.com
> >> Subject: Re: [N8VEM-S100:1375] S-100 Bus Terminator
> >>
> >>
> >>
> >> Andrew:
> >>
> >> Being a congenital penny-pincher, as well as a "tweaker", it strikes
> >> me as a lost opportunity to define a PCB like this with *lots* of
> >> unused space (and yet sucking up a full S-100 slot). At a minimum,
> >> how about filling the remaining space with a through-hole proto-area
> >> array? It would/could be accompanied by appropriate regulators along
> >> one edge but the setup/layout would be spatially similar to the
> >> buffered proto-board (replacing the buffer-area with the line-clamp
> >> area). This would leave opportunities for experimenters (with legacy
> >> S-100 backplanes) to wire-up small accessory circuits -- else no impact
on
> the termination function?
> >>
> >> Alternatively, place the bus-terminator circuitry onto the unused
> >> area of the bus-extender card and get three-in-one functionality with
> >> extension, termination, and probe functions. An example of this
> >> approach of combining termination and extension was the VTE100a
> "EXTERMINATOR"; see:
> >>
> >> http://maben.homeip.net/static/S100/vamp/cards/VMP%20VTE%20100-
> A%20Te
> >> rminator.pdf
> >> http://maben.homeip.net/static/S100/vamp/photos/VAMP%20VTE-
> 100%20Exte
> >> rminator.jpg
> >>
> http://maben.homeip.net/static/S100/vamp/photos/VTE%20100a%20Exter
> min
> >> ator.gif
> >>
> >> If trying to go 3-in-1 ends up running into real estate issues then
> >> just combine termination & extension like the VAMP.
> >>
> >> Another possibility would be to commit all/part of the (above)
> >> proposed proto-area to specific generally-useful functions. Two
> >> possibilities would be a configurable basic UART serial I/O port
> >> and/or a configurable 8 or 16-bit (E)EPROM handling up to 1 MB chips.
> >> I believe that someone pointed out recently that it would be useful
> >> to have a board with these sorts of basic functions in order
> >> "bring-up" legacy CPU PCBs in a minimal configuration. One could
> >> possibly swap one of these options for the probe in a 3-in-1
> >> configuration? Unfortunately it seems to me that when including the
> >> extension-function that the resulting routing problems when adding
> >> something like I/O or ROM might require a lot of accessory over-board
> >> wires to effectively provide a (minimal) third connection-plane. So
> >> that might not be a good idea. But the VAMP illustrates that
> termination+extension go together quite well.
> >>
> >> My preference would be to leave the existing probe+extension PCB
> >> alone, and instead look towards combining termination, Serial I/O,
> >> and (E)EPROM into a single card. This plus legacy CPU and RAM cards
> >> would result in a functional system on any "naked backplane". If
> >> some RAM could be squeezed into this multi-purpose board, so much the
> >> better :->. We have all of these circuits in tested-form, the only
> >> issue would seem to be routing. This sort of board would also be
> >> useful to a wider audience who could only populate the subsections of
> >> immediate need (e.g., not actually use the termination section if
> >> employing a self-terminated backplane) -- and this would increase the
> >> board-orders and therefore the likelihood that we'll quickly reach a
good
> ROI threshold.
> >>
> >> The bottom line for me is that a pure termination PCB seems like a
> >> lost opportunity. And might not easily reach critical-mass for a
> >> board-order :-<.
> >>
> >> On Sat, Feb 9, 2013 at 9:19 PM, Andrew Lynch <LYN...@yahoo.com>
> wrote:
> >>
> >> Hi
> >>
> >>
> >>
> >> Attached are the schematic and PCB layout files for the S-100 Bus
> >> Terminator.
> >>
> >>
> >>
> >> Please review and send any changes and/or corrections to me.
> >>
> >>
> >>
> >> Thanks and have a nice day!
> >>
> >> Andrew Lynch
> >>
> >> --
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> >>
> >>
> >>
> >>
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> >
> >
> >
> > --
> > ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~
> >
> > Tom Lafleur
> > (858) 759-9692
>
>
>
> --
> ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~
>
> Tom Lafleur
> (858) 759-9692
>
> --
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