View Full Version : A new S100 Bus Display Board

January 19th, 2018, 01:56 PM
If you do any kind of serious work with your S-100 system being able to see at a glance the status of many S100 bus signals is very useful. A number of years ago we developed our System Monitor Board (SMB) which does this well. It's now in its third version and has settled down to be a very reliable board. It is however a somewhat complex board requiring a GAL programmer and without a set of ribbon cable connections is difficult to read in the bus. It can also be a big undertaking for a real beginner. Indeed it is at times a bit of an overkill.

Many of us can remember the "Jade Bus Probe" which came out in the early 1980's. It was an extra large S100 bus board that extended above all the other boards in the bus and displayed continuously many of the important S100 bus signals in real time. It was extremely useful in developing/debugging boards. It did however suffer from a few things. A number of the S100 bus signals had to travel up the board thereby increasing their effective bus length. While fine with CPU's of the time, it does not work well with our newer "modern day" boards that run in the 8-10MHz range. That said, from time to time I use it as a "quick and dirty " tool to find on what is going on with a board that is acting up.

I would now like to introduce an upgrade on the concept, a S100 Bus Display Board. For more information about this board please see here:-


I will order a batch of bare boards for people that would like to build and use the board. Details are on the bottom of that page. Please be sure and order there. If you have never ordered before I will contact you directly for your shipping address.

John Monahan