View Full Version : JAIR8080 & Mini Imsai Front Panel Computer

June 7th, 2016, 12:52 PM
Well I completed my S100 mini IMSAI computer, based on Josh Bensadon's JAIR8080 Board (Josh's Altair/IMSAI Replacement 8080 Board) and Don Caprio's Mini IMSAI front Panel board. These two boards make a great team. Details on both Josh and Don's boards are available on the s100computers website, if you have not checked them out yet, you should. :)

I've seen a few threads from folks on this forum, wanting to get started with S100 computers, and if you cannot afford a real IMSAI or ALTAIR, and you want a real S100 bus, I think this should do it. It has for me. This is my first foray into S100, and with these two boards i have almost everything i need to get started. :) Keep in mind you will still need an S100 motherboard and a suite able power supply. Mind you if you just wanted to use the JAIR8080 (Josh's 8080 board, I'm trying to brand this thing by using JAIR8080 a lot... he he) on it's own it can work stand-alone via it's many serial connection options... :) (even FTDI.)

This sounds like an infomercial, and sorry about that, but I have been excited about this project since Josh announced his new boards. :)

If you are looking for a great all in one solution, or a board to trouble shoot your own system this may be the ticket. :) with 2 built in serial interfaces, 64K ram, 32K rom and 2 8 bit parallel ports, you would think, wow man that's crazy.... but add an SD card interface that supports up to 4 disk images for booting cpm, and you might think Damn! that's insanely great. :) And it's all done without the use of Micro controllers or any modern trickery. ( he he ). Add to that, Don Caprio's Mini Imsai front Panel board and it makes it all that much more fun. :) The replica switch paddles are awesome and feel great. It's a high quality board with high quality switches.

I've wanted this pair of boards since I saw them at VCF Mid West last year. The built in SD card reader reads standard full sized SD cards and does not require any special tools to load images on it. I'm hoping to do a Youtube video on both boards. :) This year at Vintage Computer Festival Mid West, I'm hoping to pick up some extra cards for it. Maybe a physical disk controller cards. Now, enjoy the eye candy:


more pictures in my flicker feed:


Check them out... :)

I'm excited because I just finished building it last night, and tonight i will be playing around with it. :)

Im in the process of designing a way to keep the board more rigid as my S100 motherboard does not have cage or edge guides for the cards, so I'm 3d printing something... I will post .stl files if I have luck :)

Cheers. :)

June 7th, 2016, 01:34 PM
I'm working on an open source S-100 enclosure/case, hopefully a project that will finish to kit form sometime this fall. Thinking I'll probably provide a front panel for Don Caprio's mini IMSAI panel, it's a pretty slick design! Someone had one at VCF East this year, got a chance to take a look at it in person.

June 7th, 2016, 08:04 PM
Very cool... Josh brought his to VCF east, I was there too... looking forward to see how your project develops!


July 24th, 2016, 06:26 AM
Very cool... Josh brought his to VCF east, I was there too... looking forward to see how your project develops!


Speaking of VCF MW, I think there will be three JAIR8080 systems at VCF MW this September, I'm bringing mine, Josh is bringing his and Ed, is bringing his. I'm currently collecting parts to build the ZFDC Floppy disk drive controller card (also from www.s100computers.coom) for use with JAIR8080. I know the bios code to use it was written for Z80, and that it will require some fiddling. Lucky for me Josh is building one along side with me, and he is the king of code. :) I have a couple of 5 1/4" drives I would like to use with it. :)

I love the fact that the JAIR8080 board has the built in 4 floppy drive system on SD card for convenience (and ram, and serial ports, and parallel I/O), it works great, and with the newer code and different drive formats it supports, it's even better. But I got that soldering itch again and the ZFDC board presented itself. :) Looking forward to completing it and messing with physical heavy noisy clunky drives.

Plus who's kidding who, the ZFDC has plenty of Blink'N lights and some hex displays to boot, it sure looks perdy.... SQUIRREL !!


August 24th, 2016, 06:29 AM
I added an HC-05 Bluetooth module to my Jair8080. I plugged it into the FTDI port. ( not directly, I created a little harness with a voltage decider for its RX line 3.3 volts). I also added +5 volts to the unused pin 4 on the FTDI 6 pin header to power the Bluetooth unit) as well as a jumper to detach pin 6 from the C2 chip as required in the manual. I used the spare chip spot for a pin 4 power and pin reattach point). Makes it super easy to switch back to normal serial opperation.




Works great.

August 31st, 2016, 06:00 PM
Cards are starting to pile up. I may need a larger motherboard soon. :)

I built the S100 computers S100 extender board with built in logic probe...
very nice board. :) it's working fine...

I also built the ZFDC board, but have not been brave enough to try it out.
i will most likely start a new thread for that. :)

any way I love this computer... it's wicked, and now has a high resolution (sort of) graphics card.
I'm kinda like'n graphics cards with this... i may have to purchase one of the new Dazzler II boards
soon to be available on the S100computers site. :)

September 29th, 2016, 08:45 AM
Hello all,

I received my assembled and tested JAIR-8080 from Josh yesterday, and I got the time to install it in my IMSAI chassis today.


Up and running right away! This is excellent!

All I did was go through the manual and note all the jumper positions as I originally received them (just in case I decide to go crazy, I can get back to the beginning again). Installed in my IMSAI, power on, reset, run, and VOILA! I've only explored a little bit at this point. Now I have to get my wits about me and figure out next steps. I need to back up the SD card for sure. I certainly need to find out more about the system monitor capabilities, too. I see that I can get into CP/M with 250K disks. I'll need to investigate that, as well. How to get source files and .COM files into this machine?

I'm off an running on my new adventure!

Thank you very much, Josh, for all the attention you've given me, and thanks a million for producing this awesome single board computer system. This is too good to be true!