View Full Version : SCELBI Oscilloscope/Keyboard Interface Updates

February 3rd, 2017, 07:41 AM
sorry in advance for cross posting so much

I've been busy getting ready for the upcoming VCF east event and I'm really excited about what I'll be able to show this year.

I'll show a working SCELBI 8B connected to a oscilloscope and keyboard which are used as a terminal. A cassette tape interface is used as mass storage. It will be running the vintage game, Star Shooter and SCELBI's original integrated development environment (MEA), which dates back to 1975. The SCELBI can natively assemble and run Star Shooter from source code and I'll be able to demonstrate that, as well.

The hardware is all reproduction stuff, as fully functional, original SCELBI 8Bs don't exist. The oscilloscope interface has been a particularly challenging project. There is only one known set of original SCELBI oscilloscope and keyboard interfaces. These are in storage at the CHM in California. I only had partial schematics, some excellent photos that Jack Rubin took of the original interfaces during a visit to the CHM, and a few notes in some documentation of related hardware and software. As far as we know, the original oscilloscope driver software and documentation has been lost. I've had to reconstruct the software by reverse engineering MEA's interface to it, along with gleaning a few hints in some surviving documentation that refers to the oscilloscope interface.

I now have the hardware and software working. Before VCF, I'm looking to tweak the oscilloscope analog interface board to see if I can improve the quality 0f the oscilloscope display output, as, at the moment, though it's usable, it is quite bad when connected to my Tektronix 465.

In order to more easily reproduce the Oscilloscope/Keyboard interface software, I updated my Macintosh OS/X SCELBI application to support those interfaces. The revised application is now available on Apple's app store for $5. I still have version 2.7 (without oscilloscope/keyboard support) available for free download from my website:http://www.willegal.net/scelbi/scelbiapp.html. I'm asking a little money for the latest version of the app, in order to help cover the cost of Apple Developer Membership, which is necessary in order to complete development of an IOS version, which I would like to do when I find time.


Mike Willegal