From bcf0092dd845372729693e160ac4618edfe322a6 Mon Sep 17 00:00:00 2001 From: saji Date: Fri, 2 May 2025 21:31:07 -0500 Subject: [PATCH] added initial wyse 60 repair --- content/blog/wy-60-repairs/wy-60-repairs.md | 43 ++++++++++++++++----- 1 file changed, 34 insertions(+), 9 deletions(-) diff --git a/content/blog/wy-60-repairs/wy-60-repairs.md b/content/blog/wy-60-repairs/wy-60-repairs.md index ec9e13b..0083e84 100644 --- a/content/blog/wy-60-repairs/wy-60-repairs.md +++ b/content/blog/wy-60-repairs/wy-60-repairs.md @@ -100,19 +100,44 @@ Uh, guys? Image of more cold joints on a different chip. -It can't possibly be this, right? U17 and U15 are part of character storage, and -I did see the font RAM output non-zero, meaning it had to have rendered +It can't possibly be this, right? U17 and U15 are part of character storage, +and I did see the font RAM output non-zero, meaning it had to have rendered something! I quickly cleaned up the joints and powered it on. I couldn't see it -at first, but it worked. This highlights the two styles of troubleshooting: +at first, but it worked. + +# Takeaway + +This highlights the two styles of troubleshooting: 1. Hypothesis -> Solution 2. Hypothesis -> Validate -> Solution -It feels pretty good to zero-shot a repair or fix, but it also can leave you with blind spots. -In my case, I didn't want to try to probe the board while hot, but later it became necessary unless -I just started replacing chips indiscriminately. Once I started probing, I wanted to find something that -seemed "off" before going further. I would have noticed the character RAM eventually, if I finished my -testing of the Attribute RAM. In this case it was easy to spot visually and so I didn't need to test it -any further. +It feels pretty good to zero-shot a repair or fix, but it also can leave you +with blind spots. In my case, I didn't want to try to probe the board while +hot, but later it became necessary unless I just started replacing chips +indiscriminately. Once I started probing, I wanted to find something that +seemed "off" before going further. I would have noticed the character RAM +eventually, if I finished my testing of the Attribute RAM. In this case it was +easy to spot visually and so I didn't need to test it any further. +While I was working on this, my friend was using his unit to develop a USB +keyboard adapter. His unit was slightly more yellow and has some centering +issues, but otherwise is fully functional. By the time I had mine figured out, +the firmware was mostly complete, so it was a quick flash away. I might blog +about it some time, but the protocol is really simple. + +I'm typing this last portion in Vim on the terminal, using the VT100 mode. + +( image of editing this post with the terminal ) + +# Next + +It's not perfect. I don't know much about ye olde terminal behaviors +and finding replacements for modern tools that weren't built +with a VT100 compatible in mind is a task of itself. The flow control seems +to be DTR-based, which Linux doesn't support natively. We might be able +to hack around that with a shim but that's a problem for later. It works +fine at 9600 baud using software flow control. + +To the folks who rave about the terminals of yore, I get it now.