A1 Address and Data bus display

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Joined: Apr 7 2006
Posts: 5

I put together an address and data bus display for trouble shooting an apple 1. Attached is the schematic.
The TIL311 hex displays are available on Ebay for now at various prices.
One can also find the 22 position card edge connectors on Ebay.

See the attached photos and schematic.
I used a 5V wall wart supply rather than using the 5V bus power. Be sure to attach the wall wart ground to the bus ground pins 20 and X.

Post back if you build one. Let us all know how it turns out.

Cheers,
CB

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IMG_20170220_181401_891.jpg1.36 MB
BUS DISPLAY_APPLE-1.pdf18.37 KB
IMG_0060.JPG1.67 MB
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speedyG's picture
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Joined: Nov 16 2011
Posts: 2414
Re: A1 Address and Data bus display

Hello cdreike,
welcome in the communitee. First a congrats to the interface.
It's a nice idea to convert the adressing line to hex dissply
though it demands to fist again convert to single lines themselves...
more usefull if you want to debug software in the general run....

but for debugging purposses it might be more usefull to view
the single lines themselves while debugging build and construction
there also is a contribution to display the single lines st:
http://www.appleii-box.de/A18_diagnosticcard.htm

sincerely
speedyG

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Joined: Apr 7 2006
Posts: 5
Re: A1 Address and Data bus display

SpeedyG
Thanks for the reply. I had considered building a similar debug tool, however I thought that having a Hex display would be much more understandable. I actually used my display to verify the operation of my processor section, pointing to problems in other areas of my board. Using the TIL311's also looks to be a much simpler solution. It did not take long to build my board.

Cheers,
CB

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