norwestrzh via N8VEM-S100
2015-06-30 01:20:43 UTC
No luck getting the V3 board to work. I assume that the checkout procedures posted for previous versions of the board work (in a general way) for the V3 version?
I set up the simple loop shown (input from port 30h and loop back to repeat input, infinitly), and I can see board select wiggle. Same for output to port 30h. The OUT_OE* and _LE* and IN_OE* and _LE* wiggle (seperately) as I would expect them to with input and output from port 30h.
Then I entered a little program that send 80h to port 33h and then loop sending incrementing values in the A register to one of the 8255 ports 30h, 31h, or 32h (A, B, or C). There is activity on the 8255 chip select, and WR pins. The OE* and LE* pins of U108 (373) show activity, and I can see activity on the data bus of the 8255 and the 373 (U108). BUT, nothing appears on any of the 8255 ports (A, B, C). I have tried two flavors of Intel 8255s (A-5 and A-2) and an AMD 8255, with the same result.
What am I doing wrong? Is this going to be another one of these deals where the board is sensitive to the flavor of 8255? If so, what is the "magic" type, and where can I get one (some)?
Anybody get their V3 boards going?
Roger
I set up the simple loop shown (input from port 30h and loop back to repeat input, infinitly), and I can see board select wiggle. Same for output to port 30h. The OUT_OE* and _LE* and IN_OE* and _LE* wiggle (seperately) as I would expect them to with input and output from port 30h.
Then I entered a little program that send 80h to port 33h and then loop sending incrementing values in the A register to one of the 8255 ports 30h, 31h, or 32h (A, B, or C). There is activity on the 8255 chip select, and WR pins. The OE* and LE* pins of U108 (373) show activity, and I can see activity on the data bus of the 8255 and the 373 (U108). BUT, nothing appears on any of the 8255 ports (A, B, C). I have tried two flavors of Intel 8255s (A-5 and A-2) and an AMD 8255, with the same result.
What am I doing wrong? Is this going to be another one of these deals where the board is sensitive to the flavor of 8255? If so, what is the "magic" type, and where can I get one (some)?
Anybody get their V3 boards going?
Roger
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