cheap data aq system

[Orin]

[Charset iso-8859-1 unsupported, filtering to ASCII...]
> Someone posted a message a couple of days ago about looking for a schematic for a cheap data aq system. I have found a schematic for a 11 channel, 8-bit D-A system with a parallel port interface. It is based on the Motorola MC145050. I got a 486 laptop on Ebay for $50, and the parts were about $20. I am hoping to start prototyping it this week. Since I have very little electronics experience, I expect it to be a challenge, to say the least. however, if it works it will be great, since it is very simple and cheap to build. If anyone is interested, please email me and I will send the schematic and parts list. It would be great to have someone else working on it who knows what they are doing! I have a feeling the design can be improved upon, but I want to at least get it working before I start messing with it too much. If there is any interest and the thing is successful, I might try to have some PC boards made up and do a group buy for the lists. 
One problem with the '050 and its brother, the '051 is they
hate more than 5V on the analog inputs.  It causes errors
in readings on all channels.

Unfortunately, a simple resistor and zener isn't sufficient
to cure this.  What kind of protection is on the inputs in
the schematic you found?

Orin.
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