View Full Version : S-100 Front Panel project

March 4th, 2010, 07:44 PM
Hi! John and I are working on an S-100 Front Panel project and are probably getting ready to order some "bare bones" prototype PCBs in the near future. We are doing another round on the S-100 SRAM board first but the S-100 Front Panel is probably next up.

These prototype boards tend to be expensive ($50+ each), have numerous problems, and are pretty ugly (no solder mask, no silkscreen, no gold fingers, no chamfer, manual board trimming required).

Why would anyone want to get one of these PCBs? Because we are moving into the build and test phase of the project and the design is still open and receptive to changes. If you are a hardware hacker and are interested in possibly influencing the design of the S-100 Front Panel board this would be your chance.

Once the design is finalized and the PCB readied for manufacturing it will be much more difficult and very unlikely to make substantial changes. Since S-100 Front Panels tend to be close to the hardware on those systems that use front panels it may be worthwhile for inquiry.

Thanks and have a nice day!

Andrew Lynch

PS, take a look at John's S-100 SRAM posting in this forum to get an idea of what the S-100 Front Panel is going to look like. The displays will be a separate board to mount as a mezzanine or remotely. Please ignore the insane routing as the prototype is not final yet.


March 4th, 2010, 08:10 PM
I'd probably be interested in one of these...now that I've got a working S-100 Z-80 card, a front panel would be handy in troubleshooting my RAM board.

What sort of displays are you using with this?

March 5th, 2010, 03:54 AM
Hi! The displays have been a major design issue since the beginning and we finally settled on the mezzanine board approach. The displays and switches are exported to a set of dual row headers where you can attach ribbon cables to the remote display. The first display board will probably contain 10 HP5082-7340 hex displays. We don't have prototype PCBs yet so haven't worked out all the details on the display board size and/or mounting issues yet. I believe we'll be adding some mounting holes to the main PCB to support a true mezzanine (stand off hardware) as well as a remote mounted.

Obviously those HP5082's are rare as hen's teeth and expensive to match so we are probably going to have to make a few display boards using other devices such as TIL311 and LED bars. The display boards will be prototype units at first and hopefully later be available as manufactured PCBs. LED bar displays are my current favorite since they are dirt cheap and commonly available however there is no dispute that HP5082's are much nicer displays and easier to read. TIL311's would work well too and aren't quite so expensive but still not cheap nor common. I suppose if someone wanted to felt ambititious they could make a uC controlled display as well but then latency can be an issue.

My point in raising the topic is since S-100 front panels are typically unique to specific systems if other hobbyists want input into the design they should get involved while the design is still open. If there is no input until the manufactured PCBs are available then there it is too late to incorporate any features they may need or want.

Along those lines, we are on the path to a 100% open hobbyist S-100 system. We still have a long ways to go but this is what we have so far:

S-100 backplane (6 slots w/active terminator)
S-100 prototyping board
S-100 buffered prototyping board
S-100 IDE
S-100 keyboard (PS/2 to parallel ASCII)

These are in work:
S-100 SRAM (prototype PCB in build and test, rapidly approaching manufactured PCB)
S-100 Front Panel (near prototype build and test)
S-100 EPROM (early design)

These are planned in near term:
S-100 fast Z80
S-100 serial console (dual serial & maybe some other features TBD)

planned long term:
S-100 16 bit CPU board(s) (TBD)
S-100 versions of N8VEM ECB board(s) (TBD?)

fantasy land:
S-100 chassis
S-100 power supply
S-100 floppy controller

Other hobbyists are welcome to get involved as appropriate. There are many ways to help move the project along and in my personal opinion one of the best ways to help is buy the first generation or two of PCBs so we can work out the kinks. Yes, the early boards often have problems but they are generally solvable with minor corrections. Early builder feedback is essential to improving the design but even if they don't build the board it still helps the project move forward.

Once we get past those first units the boards improve dramatically but if we can't get a couple of PCBs iterations through we are stuck. It is sort of a catch 22 since I imagine most hobbyists would rather wait until "final" PCBs are available but those won't happen until the early boards find homes first. For example, the S-100 IDE and S-100 keyboard projects have had a revision or two and have more corrections and improvements planned. However they are basically waiting for enough builders to warrant their PCB respins. The S-100 IDE has two minor fixes planned and the S-100 keyboard has about six or so.

I am pretty sure the same pattern will apply to the other S-100 boards in the works.

Thanks and have a nice day!

Andrew Lynch