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View Full Version : SCELBI 8B with Oscilloscope Interface Demonstration Video



mwillegal
May 14th, 2017, 07:59 AM
The following link will lead you to a video showing off many of the components of a SCELBI 8B with audio tape, keyboard and oscilloscope interface. It starts with a description of each individual module. Then the components are all “hooked up”. The systems is powered up and some of the capabilities of the SCELBI system are demonstrated.

http://www.willegal.net/SCELBI-8B.mov

enjoy,
Mike Willegal

inotarobot
May 16th, 2017, 05:56 AM
I have only watched the first 57sec of your movie on my laptop. Already I decided to pause it. Why you may ask ?

Well I am hooking my laptop up to a 23" screen, so as to better enjoy, what I sense, is going to be a VERY interesting movie.

livewire
May 24th, 2017, 01:44 PM
Mike, thanks for posting that video!
So very informative, but also raises so many questions due to the lack of documentation
regarding hooking it all up. I still have a few months until I get to that phase on my 8B build. :?::?::?:

mwillegal
May 25th, 2017, 04:41 AM
Most of the information about building a SCELBI and hooking it up, can be found somewhere in the SCELBI schematics or HW documentation. The Oscilloscope interface is the exception, as original HW documentation hasn't turned up for that interface.

I've been working (in fits and starts) on digitizing the original HW docs and have it mostly done. I also started on a Oscilloscope doc, but I have a ways to go with that. Eventually I'll go through and add additional notes based on what I've learned. Keep in mind that much, but not all, of what I've learned is already documented in my blog.

regards,
Mike Willegal


Mike, thanks for posting that video!
So very informative, but also raises so many questions due to the lack of documentation
regarding hooking it all up. I still have a few months until I get to that phase on my 8B build. :?::?::?:

livewire
May 25th, 2017, 08:33 AM
I appreciate all your efforts bringing the SCELBI back into the light.
PLEASE keep up the great work!
FWIW, your Mimeo (Apple 1 clone) documentation is superlative. A standard that all kit makers should follow.

Do BOMs exist for the for the SCELBI 21XX add-on boards?
I could not find any, it was a real electronic adventure deciphering the original schematics vs the (most excellent) layout pics
to figure out the poly & disc capacitors, transistors & fuse employed on the 2103 tape read board.
I just wanted to relate my observations. Please don't take it as a complaint.
I also do not want to publish a BOM on this, it may be wrong due to my guesses on parts not labeled in the drawings.
We'll see if I guessed right when I power up my Scelbi. Ha-ha!

Roland Huisman
May 25th, 2017, 11:38 AM
How nice! I'be been thinking earlier of building a Scelbi.
But when I see this I would love to make one! Awesome!

I wonder how close my mark 8 matches with the Scelbi.
http://technischmuseum.nl/devices/Mark%208/Mark%208.html
If I remember correctly my Mark 8 has 14KB of ram.
It has also a tape drive and a monitor interface.

It came with a huge amount of documentation.
I still have to figure out a lot...

Regards, Roland

38785

mwillegal
May 26th, 2017, 06:12 PM
I have created spreadsheet BOMs for the I/O cards, but they need to be cleaned up before I can publish. For the most part, I use 2n2907 and 2n2222 transistors and 1n914 diodes. Use low ESR film capacitors where they are used on the original boards, rather than ceramic caps, it will make a difference in some circuits.

Regards,
Mike Willegal

mwillegal
May 26th, 2017, 06:15 PM
That Mark 8 looks loaded with extras.

Regards,
Mike Willegal