New S-100 Boards
This section of the web site contains a listing of new S-100 boards
I and others have recently constructed. Still utilizing the basic IEEE-696
S100 bus format, we are incorporating modern designs into these new boards.
The long term goal being to adapt most major microprocessor chips (and support
IC''s) to the S-100 bus. We have for example designed
new master/slave S-100 boards with CPU's from the 6502, Z80, 8086, 80286 and 80386
family's, and the 68000 Motorola family. We will be continuing this approach
all the way up to more advanced 32 bit CPU's like the 80486 CPU and CPU's like
the Propeller and RISC/ARM chips. This has been, and will continue to
be, a multi-year project. A core of enthusiastic people have got together
to do this. This process has now being going on for a
few years with the number of boards well into the 1000’s.
I must stress however this is a hobby based group of
people (spread actually around the world these days). There is no central
organization or person “in charge”. I and a few others design and
produce new S100 boards (at our own expense) and when done, typically do a
“group purchase” of a new board. These are bare boards which must then
be stocked with chips etc. Typically I provide basic build/testing
instructions and if needed, basic software.
major ones are listed in the table below.
In many cases updated versions of the boards were/are being made.
It is unfortunately a bit difficult for new people to get started since many
by now already have their basic starting boards.
from time to time a new “run” of an old board is done. This needs
somebody to organize and arrange a run. It is more trouble than you
might think to organize. The boards are usually made by a (Chinese)
group call PCBcart.com for us. The required board fabrication Gerber
files are available at the bottom of each board’s description on
this sites web page.
To get started and find out more a boards availability it is probably best
you follow this forum
From time to time a "board run"
is proposed by a member. Later when you are more experienced, you
could start one yourself.
Also a few long term users mentain a stock of some of our most popular
boards. They are listed here (along with a numberof other "ReteroBrew
Computer" boards). Please see here:-
for a list of boards available.
Alternatively you can get started quickly by scanning eBay for S100 bus
motherboards, computer systems or S100 bus boards themselves.
a good place to start:-
Index Table Of New S-100 Boards
As new additional prototype and final S-100 boards are
made they will be documented here:-
Tom Lafleur has kindly put together an
Excel spread sheet list of components for a number of the above boards.
For some of the more recent boards Rick Bromagem has supplied the BOM list
at the bottom of each web page.
It can be seen here.
MY OWN S-100 SYSTEM
By way of showing the evolution of these boards, I will
describe my own S-100 IEEE-969 system. This is a completely "homebrew
system". Originally built in the early 1980's utilizing many of the S-100 boards
of that era. As I add new S-100 boards, I will go into some detail in
an effort to help others build similar systems or allow them revive S-100 systems
they may have stored away or have recently acquired.
While none of this is rocket science, it does require some degree of
electronic knowledge, familiarity with the S-100 bus and for the software, a
working knowledge of CP/M, CP/M86 and MS-DOS (Programs, BIOS & Drivers) .
If you wish to become more informed about the S-100 bus itself try and get your
hands of the book "Interfacing to the S-100/IEEE696 Microprocessors"
by Sol Libes & Mark Garetz. This book is commonly regarded as the "bible"
for this field.
This will be a long term "work in progress" report. The index table above will
direct you to new S-100 boards built or being tested. See each boards
section for more details.
Readers such as yourself are encouraged to participate either directly by contacting
me via e-mail (substitute
the AT for @), or better, via one of the S100 related
Here was my starting point for a S-100 system built with boards from the 80's.
With this as a basis over time, we will swap out many of these boards into new
more exciting and efficient boards using more modern IC's.
MY SYSTEM IN 2009
MY SYSTEM 2011
MY SYSTEM 2013
MY SYSTEM 2014
My S-100 System (As of April 2014)
Getting Started in KiCad.
All our boards are designed using
This is an open-source software tool for the creation of electronic
schematic diagrams and PCB artwork. This is a fairly complex program to
learn and will typically need weeks of practice to build up a board. After
the board circuit is generated with KiCAD it must then have all the
chips arranged on the board and connected with 100's if not over a 1000
traces and vias. This is done with another program called
Finally the resulting Freerouter files must be converted to
for the factory to actually fabricated the board.
For most of our boards I provide the most recent Gerber & Drill files to
have a board fabricated. You may use these files -- at your own risk -- to
have any board on this site made for non-commercial use.
KiCAD is an open-source software tool for the creation of electronic
schematic diagrams and PCB
artwork. Beneath its singular surface, KiCad incorporates an elegant
ensemble of the following standalone
KiCad project manager
EESchema schematic editor
CVpcb footprint selector
PCBnew circuit board layout editor
GerbView Gerber viewer
Bitmap2Component component maker
KiCad can be considered mature enough to be used for
the successful development
and maintenance of complex electronic boards. KiCad does not present any
board-size limitation and it
can easily handle up to 16 copper layers and up to 12 technical layers.
KiCad can create all the files
necessary for building printed boards, Gerber files for photo-plotters,
drilling files, component location
files and a lot more.
Despite its similarities with other PCB software tools, KiCad is
characterized by an interesting work-flow in which schematic components and
footprints are actually two separate entities. This is often the subject of
discussion on Internet forums.
The KiCad work-flow is comprised of two main tasks: making the schematic and
laying out the board. Both a components library and a footprints library are
necessary for these two tasks. KiCad has plenty of both. Just in case that
is not enough, KiCad also has the tools necessary to make new ones.
The main KiCad web site can be seen
here. From there you can obtain excellent instructions, videos and
examples as to how to lay out printed circuit boards.
However be aware
to layout complex printed circuit boards like we have here needs
hours of experience and should not be taken on lightly.
To get started please review the following files:-
Please note, recently (Dec 2015), a newer version of
KiCAD has been placed in the public domain. Unfortunately some of the
files for the previous version of KiCAD (the above 2013 version) are no
longer compatible with this version. They can be converted, but for now I
will stick with the 2013 format. All our current files should work with
that version. It is way more than adequate for all our needs.
Initially you use the eeschema button to draw your
schematic. This is by far the most time consuming and hardest part of
the program. As I said above it takes many long hours to master this
part. You then need to convert this schematic to an actual board
layout with all the IC's etc. physically in place.
From your schematic you make a .net
You then call in the second program cvpcb
that uses the .net file to assign each IC in your schematic an actual board
"footprint". Most common footprints are already available as .mod
files that come with the many KICAD "libraries". Cvpcb
generates a .cmp with all the
boards components footprints.
You then use the program pcbnew to do the actual board layout.
It utilizes all the .net and .cmp file data to layout your board. All the traces are shown initially as lines connecting IC pins to IC pins.
Pcbnew generates a board layout file with a
.kicad_brd extension. (Note older version of
KiCAD used a .brd file extension. This is no longer
Also included (see bottom of this page) is a a collection of S100
footprint files specific for our S100 boards. Make sure when you
setup KiCAD that these files are on tthe default file search paths for these
programs. (Set Preferences, Library, User defined serach path....
for eeschema, cvpcb and pcbnew).
For small simple boards you can move/edit etc. these lines by hand. For
complex S100 boards like we have here however, it is really
necessary to use a trace layout program called
Freerouter. The windows
.exe program can be downloaded
It is completely self contained and should run in any folder on your system.
You feed it a .dsn file (generated with pcbnew using the
file menu "Export" command). It
returns a .ses file which is reaccepted by pcbnew.
See the above diagram. Rout optimization for complex S100 boards like these
is a slow process. Complex boards can takes days. You can watch the number of
"vias" decrease, and the overall length of all the boards
traces decrease over time. When you see no further improvement its
time to stop. The critical file we want in the end is the pcbnew
generated .kicad_brd file with the optimized board traces
supplied by freerouter. That file is then used by the pcbnew "Plot" command
to generate the boards "Gerber files". These files are
required by board
manufactures to fabricate your board.
This site (at the bottom of each boards description page) has the required .kicad_brd
file you need to generate the Gerber and drill hole files for manufacturing
S100 Board Manufactures.
Almost any printed circuit board manufacture can fabricate these
relatively simple two sided printed circuit boards. Issues are cost, time
and what their setup/minimum order is. Highly recommended for production
boards (with gold plated fingers etc.) is
PCBcart.com and for prototype boards
The latter have a $33 deal per board if you order 4 or more boards. However
unfortunately they don't supply gold plated edge connectors at this price.
For such final production boards PCBcart is the best.
Most of the boards on this site use common 74LSxx style chips. If you are
going to build a number of S100 boards (or repair them), you really should
build up a stash of these chips. I get most of my components from Jameco,
Mouser, Anchor-Electronics, Unicorn Electronics or for discontinued chips
UTSource, and in that order. I use Jameco for all the support stuff,
sockets, jumpers etc. I wish I had time to write-up a detailed BOM for
each board, fortunately Richard Chin and Rick Bingham have done so for some
boards - thanks Richard & Rick. If you want to contribute please send one on to me.
KiCAD Download (Note this is a large file, 197MB).
KiCAD Folder of custom Footprints etc.
Advanced Circuits Prototype Boards site
PCB Cart Commercial Boards
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