HP-25C Eumulator

[Chris Chung]

(09-30-2014 07:39 AM)brouhaha Wrote:  

(09-22-2014 06:09 PM)Chris Chung Wrote:  Thanks Eric for the original nonpareil work! I tried to email him but has not yet got a reply, may be his site / account is not very active these days.

I no longer use that email address, because it is overrun with spam, even with filtering.

Then I say thank you here for your work on Nonpareil. I hope I had not change it's spirit (very true to the micro second emulation) too much. I really enjoy seeing it come to life on a 2"x3.5" PCB. I do have to cut certain corners to make it work on the platform I want.

(09-30-2014 10:42 AM)hp41cx Wrote:  Depending on the value would be 2 units (25) and 2 units (Datamath)

The Datamath kit will be put up on the 43oh.com store in a couple of weeks. It's not my website but I am a long time member on that forum and it's typical that the owner create kits from popular member's projects. He actually initiated the Datamath "group-buy" and managed to shipp 20+ units. I do not know how much it will cost you. Should not be very different from the "group-buy" price of about $20, +$10 for assembly option. I will post here when that comes up.

You can see the original Datamath "group-buy" thread here.
http://forum.43oh.com/topic/5537-group-b...e-display/
It took us like 3 months end-to-end when members received their kits. It would be similar w/ the NP25 to get it right.

For the NP25 (that's what I called it for now) build. Looks like we will have no trouble getting around 10 units going. I will need a few weeks to work out a reliable firmware (and another version of PCB). With the 6V design, my tactile buttons are very jumpy (all is good if I power it externally). Probable caused by no ground shields, stray capacitance, etc. I have no o-scope to find out. I may go back to 3V unregulated supply which is also simpler. The fact is that there can be many things go wrong when you try to duplicate an h/w project so I would like to spend more time testing before finalizing firmware and PCBs.

I will keep you guys posted on the progress and we can count orders when I am ready to procure components.

If there is something you like to see in the final kit (or any questions), please comment.