(04-18-2020 08:20 AM)Paul Dale Wrote:  The scope trace is very pretty and interesting.

Is there a timer that can be used to produce the 10kHz modulation? Without that, it will be quite a challenge.


Pauli

(05-01-2020 03:47 AM)teenix Wrote:  Edit: Some other circuit boards came today for another HP project I've been playing with which uses the same PIC, and it looks like these chips can be soldered with simple tools from home :-)

(05-01-2020 12:29 PM)Hans Brueggemann Wrote:  no worries, even the "experts" are just cooking with water, solder flux is your friend:
fine pitch soldering done right

(05-01-2020 03:47 AM)teenix Wrote:  Hi all,

I received some circuit boards the other day so international postage is still working to a degree :-)

I decided it should be ok to submit the HP-97 replacement CPU prototype designs for manufacture, of which two are required, and hopefully I'll have them in a few weeks to begin populating and testing - exciting.

The 64 pin TQFP chip (pin spacing 0.5mm) might be a challenge to solder but I think it should turn out similar to the 44 pin chips used in the other boards which are quite easy.

(05-01-2020 03:47 AM)teenix Wrote:  Edit: Some other circuit boards came today for another HP project I've been playing with which uses the same PIC, and it looks like these chips can be soldered with simple tools from home :-)

cheers

Tony

(05-04-2020 09:47 AM)Harald Wrote:  That sounds grerat! I am tempted to take appart my working 97. I probably wont do it though

(05-04-2020 09:47 AM)Harald Wrote:  Now I am intrigued. What is this other project you are talking about?

Cheers,
Harald

(05-04-2020 10:17 AM)teenix Wrote:  

(05-04-2020 09:47 AM)Harald Wrote:  Now I am intrigued. What is this other project you are talking about?

Cheers,
Harald

It's in the secret laboratory down in the dungeon at the moment :-)

cheers

Tony

(05-13-2020 04:21 PM)AndiGer Wrote:  Tony,

When will you go to work on this one?
https://www.hpmuseum.org/item/product2.htm ... LOL :-D

(05-13-2020 07:57 AM)teenix Wrote:  Hi all,

It will be a bit of an unknown wait for the unpopulated prototype 97 CPU board to be delivered so I thought I might try my hand at a Woodstock replacement CPU board while I'm waiting.



It looks ok so far but will need a lot of work to finalize. The one board will suit all models including Constant Memory types.

I really would like a drop in replacement but there are connectors on the original board that have no replacements these days. Specifically the inter PCB connectors of which there are 2 types fitted to these boards. These will have to swapped over from a dead board which shouldn't be too hard.

You never know your luck tho.

On a side note, does anyone know if it is possible to contact Tom Osborne?

cheers

Tony

(05-22-2020 09:20 PM)Harald Wrote:  That looks really nice!
The connectors are a little tricky to solder. Getting them all in a straight line is the difficult part. I can't think of a replacement either though.

Cheers,
Harald

(05-23-2020 10:36 PM)PANAMATIK Wrote:  Great work!

This board was in my mind when I thought about a HP-25 replacement in 2014, before I decided to make only the new ACT chip. Alignment of the contacts shouldn't be difficult. I often accidentally unaligned one or two of them and it was easy to adjust.

What do you use as battery contacts?

And not to forget to ask just for my personal interest:
Is there also Real Time Clock and GPS and Infrared Print, alphanumerical LED Display, 512k Flash memory and Power Down mode included?

This large board space would allow for many many new features, including running Linux or windows on it. Sorry, I apologize for these, they would not be a good idea, perhaps better for today, a self driving car application, or KI based general math solver for functions, which are not yet discovered.

Bernhard