We have a great thread on "best practices". But we should have a thread (sticky) where dummies like me can tell the world were we messed up.
I messed up pretty good this weekend. I have some of those permanent protoboards from Adafruit (
https://www.adafruit.com/product/590). I really love the quality of them.
So, recently, I started to build a very minimal 65C02 computer using a couple of them. Thinking I was being really smart, I managed to get the CPU, RAM, ROM and a single NAND on this one board. Basically a computer minus I/O.
While I did get it to free-run (see my other post), I made a few bone-head mistakes.
1) For whatever reason, I decided to leave the bottom two rows empty. I still don't know why I did this. That protoboard has 60 rows. So, now I have 58 to work with. This caused a MAJOR problem.
2) Because of #1, I then decided to put the CPU and NAND gate next to each other with no gap between the two. I didn't anticipate that the IC's would need a little space OVER the sockets. I was assuming the sockets represented the vertical space needed for the IC (no, I didn't dry-fit them before hand). :-/
So this makes the NAND gate actually bump into the CPU. With a little force, I was able to nudge the NAND in its socket. But it's very tight and not completely in the socket (although, it's in there good enough to work...but over time it may drift back out).
3) I left ONE row of space between the CPU and the ROM. I left this space for the decoupling caps. I thought I was being smart here. But again, I didn't anticipate the space needed for the actual IC's. Fortunately, it actually fits right in with no trouble inserting the chips. The trouble comes when trying to pull the ROM back out to program it. NO I didn't use a ZIF socket. And no, I can't program in-circuit because of the programmer I have. Well, I could probably wire something up temporarily but I don't have much space left over. So when the CPU and ROM are inserted, there is NO ROOM to put my chip puller in. I have to pry it out on one side only. Or, pull out the NAND and CPU just so I can pull out the ROM.
I about destroyed the ROM trying to pry it out.
So, that's my woes for today. LOL
I have a large bucket of my "failed" projects. Tons of boards I've messed up. But, I guess that's how you learn. And boy, have I done a lot of learning!
I guess I shouldn't call this adventure a full failure since it does technically work. But I don't know if I will try to salvage it.
See, the thing is, I can solder about 5 times faster than I can wire-wrap. Despite my poor eyesight. But, I have trouble sharing 2-3 wires on the same pin while I solder. Which is why I like these permanent protoboards.
So for the beginners out there...the lesson for today is....
1) Dry fit all components before you put solder to it!!
2) Leave enough working space around each component. Doesn't have to be much. But enough room for a chip-puller is a good idea.
3) Don't try to be uber-clever like I was (trying that is). In other words, unless you're a master maker, don't cram 4 components on a small board if you then have no room to work on them.
4) Use ZIF sockets for chips that you will remove frequently!