Building MicroSci/Franklin FDC clones

11 posts / 0 new
Last post
Offline
Last seen: 2 hours 54 min ago
Joined: Jul 5 2018 - 09:44
Posts: 2559
Building MicroSci/Franklin FDC clones

Here is what I am builidng today...

 

Just waiting on a Mouser order for a few of the parts I didn't have on hand...  I'm building 5 of these.  I don't really need all of them but it seems like I can't make myself not complete PCBs I order.

 

This is a board it would be very interesting to see someone design a version of using PCDs like maybe 22V10 GALs to reduce the chip count.  I'm thinking that maybe it could be resuced to maybe 5-6 chips total including the 2716.

 

Offline
Last seen: 2 hours 54 min ago
Joined: Jul 5 2018 - 09:44
Posts: 2559
Here it is now...  I haven't

Here it is now...  I haven't tried it yet because I am not sure how to adjust the two trimpots.  I think I may need an oscilloscope for that which I don't (yet) have.  I ordered a cheap one due to not gettig any feedback on the ones I was looking at.  Hopefully it will be good enough to do this job.  Unfortunately it is coing on a slow boat from China so I am not sure when it will get here.

 

If anyone knows how to adjust these things I'd appreciate some info.  I probably should read the documentation, maybe it has something in there.

 

 

Online
Last seen: 1 hour 25 min ago
Joined: Jun 29 2018 - 16:55
Posts: 578
Looking nice! I have a good 2

Looking nice!

 

I have a good 2 channel scope here, FWIW. 

Offline
Last seen: 2 hours 54 min ago
Joined: Jul 5 2018 - 09:44
Posts: 2559
Do you have any

Do you have any recommendations for scopes or what specs i need?

Offline
Last seen: 14 hours 25 min ago
Joined: Apr 26 2016 - 08:36
Posts: 678
Any half decent brand old

Any half decent brand old-school 100 MHz scope is fine.

Anything from HP, Tektronix, B&K is perfectly adequate.  And you can pick one up for peanuts these days.

I got a 100 mHz digital HP 'scope a few years back for $150 and it works great.

The days of old analog 'scopes are coming to an end - they're not supported, their internal components are reaching the end of their useful lives, and spares are hard to come by.  Old-school digital 'scopes are still pretty relevant in terms of reliability and usability.

And be sure to get a decent set of probes to go with it.  Many eBay 'scopes don't come with probes.

 

The new school stuff is pretty slick too, but you should be prepared to pay $400 or more for a decent example.

I especially like the new stuff from Rigol, but it's beyond my means presently.  They do all kinds of stuff like storage and the ability to do basic logic analysis.

Pretty fancy stuff. 

There are lots of 'scope vids here with reccomendations:

https://www.youtube.com/@EEVblog/videos

I like this guy because despite his down-under accent, he speaks clearly and  in layman's terms.

 

 

Online
Last seen: 1 hour 25 min ago
Joined: Jun 29 2018 - 16:55
Posts: 578
I went the Rigol route. I

I went the Rigol route. I chose a 200mhz 2 channel but in retrospect a 100mhz 4 channel for the same price range might have made more sense. Still I have already fixed several things using the Rigol, up and running after a couple youtube clips on calibrating the probes and basic usage. 

Offline
Last seen: 14 hours 25 min ago
Joined: Apr 26 2016 - 08:36
Posts: 678
Show us your 'scope.  Post a

Show us your 'scope.  Post a pic or four.

 

 

Online
Last seen: 1 hour 25 min ago
Joined: Jun 29 2018 - 16:55
Posts: 578
baldrick wrote:Show us your
baldrick wrote:

Show us your 'scope.  Post a pic or four.

 

Here's a recent repair log where I was using it, with several photos.  Ended up fixing a video sync and RAM issue with its help. 

 

https://www.arcade-projects.com/threads/prebillian-space-pool-jamma-bootleg-repair-log.27988/

Offline
Last seen: 2 hours 54 min ago
Joined: Jul 5 2018 - 09:44
Posts: 2559
As usual, I was being

As usual, I was being forgetful..  the calibration instructions for the two trimpots are right there on the project...  An oscilloscope is indeed needed.  I ended up ordering a Hantek DSO2D15  which is a 150MHz 2 channel.  I may end up regretting not spending the $$$ for a Rigol 200MHz 4 channel, but this one was between 1/3 to 1/2 that price.  It is supposed to be here on Monday so hopefully I will be able to get this card going.

 

Offline
Last seen: 14 hours 25 min ago
Joined: Apr 26 2016 - 08:36
Posts: 678
That Hantek 'scope is

That Hantek 'scope is perfectly adequate.

And it comes with probes as a bonus.

Offline
Last seen: 2 hours 54 min ago
Joined: Jul 5 2018 - 09:44
Posts: 2559
baldrick wrote:That Hantek
baldrick wrote:

That Hantek 'scope is perfectly adequate.

And it comes with probes as a bonus.

It seems like it should be fine.  I just have to figure out what I'm doing with it.  I haven't really used a scope much since I was in college and they were a lot simpler back then.

 

Log in or register to post comments