Thread: Ortonview PCB
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Old 7th Jul 2021, 12:45 am   #29
Slothie
Octode
 
Join Date: Apr 2018
Location: Newbury, Berkshire, UK.
Posts: 1,287
Default Re: Ortonview PCB

Quote:
Originally Posted by Mark1960 View Post
The pinout of the 74ls365 sometimes works better when rotated 90 degrees. That would also avoid having the inputs to one buffer threaded through the pins of the other, depending on which direction the input and outputs are coming from.

Did you try prototyping the buffers to check if it fixes the ram corruption?
No, the reason I'm making a board is my attempts at making prototypes on breadboard and matrix board have just been a hassle. I spent a long time at the beginning of the year with a number of attempts to make a breadboard or protoboard version to allow testing various scenarios to little avail (my eyesight isn't great for fiddling with tiny wires). I had a few health problems in March so the project got shelved, but I've picked it up again. If the buffers don't work or make it worse I'll just remove them and jumper the pads of the buffer. I also want a card that I can attach a logic analyser reliably to while I experiment with the firmware, because I'm pretty sure that Karen got it 99% there and it should be a matter of identifying a timing problem or some quality-of-signal issue somewhere causing unintended memory accesses, all of which will be made easier to diagnose if I'm not battling with loose wires or dodgy test connections! I still think that there may be some obscure bug in the firmware but you can only do so much without being able to do some real tests on reliable hardware!
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