Hello everyone,
I've been working on a TF534 build to get some practice in before the TF536 boards get here.
Things have gone reasonably well and the board boots diagrom now, but I'm trying to track down some memory problems. If I scan $40000000 to $40400000 then I get this:
I think this is telling me that it could read the bottom 16 bits ok, but the top 16 bits are duff. Or have I got that the wrong way round?
I'm thinking it could be:
1) Bad solder job on IC6/7
2) Duff IC6/7 (quite plausible as I've had them on and off a couple of times)
3) Bad solder job on RAMCS2/3 on the RAM CPLD
I've reflowed and inspected a couple of times, so I'm leaning towards 2)...
Neil
Neil's TF534 buiild
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- arkadiusz.makarenko
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Re: Neil's TF534 buiild
I had a lot of problems with soldering RAM chips.
I took needle and checked each leg to be 100% sure that they were soldered.
I took needle and checked each leg to be 100% sure that they were soldered.
Do not trust people. They are capable of greatness.
~ Stanislaw Lem
~ Stanislaw Lem
Re: Neil's TF534 buiild
Hi Neil,arkadiusz.makarenko wrote: ↑Wed May 20, 2020 11:11 pm I took needle and checked each leg to be 100% sure that they were soldered.
Built a TF534 a few weeks back, had a few issues with the memory scan on the initial boot.
Found my issues by conducting continuity tests between ram chips on the address lines. If you have Eagle or another software package that will read the board file, you can easily follow the circuit and check your soldering.
As @arkadiusz.makarenko indicated above a couple of fine needles attached to the multi-meter probes, and check each leg is connected will also identify ordinary solder joints.
Hope that helps
Life is really simple, but we insist on making it complicated - Confucius
Re: Neil's TF534 buiild
Thanks for the tips guys. Will give it another shot this evening
Re: Neil's TF534 buiild
Success!
And here's the finished article. Things were getting a bit hairy around memory town there, as you can see
Well, I've learned a huge amount putting this together. I'm sure the 536 build will go a lot more smoothly.
Thanks for your help, and thanks @terriblefire for creating it! Can't wait for my 3.1.4 ROM to get here so I can really try it out...
BTW, I have a few boards left over. If anyone's interested, shoot me a PM
Neil
And here's the finished article. Things were getting a bit hairy around memory town there, as you can see
Well, I've learned a huge amount putting this together. I'm sure the 536 build will go a lot more smoothly.
Thanks for your help, and thanks @terriblefire for creating it! Can't wait for my 3.1.4 ROM to get here so I can really try it out...
BTW, I have a few boards left over. If anyone's interested, shoot me a PM
Neil
Re: Neil's TF534 buiild
Great work Neil, was it just a few flaky solder joints in the end?
Life is really simple, but we insist on making it complicated - Confucius
Re: Neil's TF534 buiild
Yeah, one on the big CPLD and a few on the RAMs. First time working at this tiny scale, but starting to get a feel for it now.
Re: Neil's TF534 buiild
Hi neilo040
Since terriblefire deleted the TF534 Github repositories there aren't any Kicad or Gerber files, I wonder if you could point me in the right direction for these, please.
I know you were selling some PCBs on eBay in 2020, I'd like to make a board or two up and a PCB stencil would save a bit of fuss and bother.
Help appreciated!