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View Full Version : Idea for a new project?



MykeLawson
February 21st, 2015, 04:02 PM
We have extender boards, both basic and loaded, bus probes, etc. Anyone give any thought to a static S-100 card tester? It would have one S-100 buss slot, DC power for the card under test, built in oscillator, etc. Each of the possible (useable) pins would/could have standard tip jacks; one for a ground, one for a pullup resistor, and another for connection to an external breadboard, or to the oscillator circuits. The oscillator taps could be the standard 2, 4, 6, 8, etc. MHz and maybe even a function generator so you could 'slow pulse' some of the inputs. And maybe have a set toggeled flip flops, or pulse circuits with taps that could also be used. I know it could test 'every' board ever made, but I could see that it could be used for testing memory, IO, video, etc. You could even get fancy and put hex displays and indicators for use with CPU cards. I could see a slopped desktop unit with a flat part on top for the S-100 connector. Any thoughts? I can certainly see a need for it by me as I put my S-100 project together. Nice and easy to probe with a scope, meter, logic analyzer, etc. I'm thinking that with something like this, you could statically test a single card, and not worry if the rest of the system worked, or have to depend on the rest of the system working to test your card.... I will probably have to put one together knowing how things go with me, so I wouldn't mind any thoughts or ideas; and I will certainly post whatever I come up with.

monahan_z
March 1st, 2015, 11:15 AM
Have considered something like this many times Mykel, even to the point of adding an IC (PIC or Propeller for example) on the board to scan/display signals. The problem is it's a lot of work. When I compare that with say the SMB in single step mode (perhaps after setting a hardware 20 bit address breakpoint etc.) its really hard to justify the effort (IMHO). A simple logic probe tells a lot. A multichannel logic display (USBee, Saleae etc) is what you need for difficult timing problems. Bad IC's, traces, sockets, wrong jumpers and the like quickly show up with a simple logic probe.

John