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made this what I assume (need to probably double check) https://docs.google.com/spreadsheets/d/1mYFaJtgVhPvKsuKDdjkZC5vIky9P8YRwqAQSOlFhX0Q/edit?usp=sharing IC buy chart/map with links
I've found quite the bit after searching for a while!
I am really enjoying it. I'd love to get a cracked iie regular and put it into a maceffects clear case.
I noticed that! So many off ebay were just stamped/prodded with school logos. Really fascinating. I'm happy to leave mine as is. But I...
Received last week but just now getting around to posting it.
Well after searching a bit for a iie, I bit the bullet and decided to gamble on a $100 apple iie off eBay.
What will come with it? Does it really come with monitor?
Opened it up, wrapped decent, would've liked a bit more...
Glad to see another /// thread at the same time ;) saw your post on my thread!
I'd definitely reseat all the chips. Hopefully all yours aren't rusted out like mine. Those chips were known to "wander out of place"
For the bottom board (metal casing that it's screwed to) you can see my post, I...
Hopefully yours actually works! Or at least more life than mine ;)
Mine still hasn't been put back together yet.
Extremely busy week at work leading up to the holidays
Hoping to dive back in either next week or after new years.
Fully disassembled last night and washed
Photo mid wash
It has gotten a full alcohol bath earlier but didn't get everything.
It got a FULL bath last night, lots of scrubbing to get off stubborn parts, cleaner than ever now.
I might try the vinegar bath. Wait a bit for the regular to dry or...
It's probably kicking and screaming as I take it through it's timing paces
But I'll be damned if it's not working! Just a few hiccups :) What's a fun project without hiccups though.
I'll admit, I took the whole thing apart, labeled every IC, and gave it a nice scrub, soap and water. It'll get...
Most things that look like that have continuity from what I've tested (bottom of the board where I've been focusing)
I tested a couple of the traces that are right next to each other on the top of the board (where it was in the absolute worst condition, rust and everything) and some of them are...
Well, in an unexpected place.
Keyboard logic!
https://apple3.org/Documents/Schematics/Keyboard%20Logic.jpg
APPLE /// LOGIC SIGNAL SOURCE
Signal Location Meaning
KVCC 9-4b KEYBOARD VCC
From the manual
Keyboard Light: The keyboard light indicates the VCC is...
New on the list of things that just screwed up.
A resistor that blew out.
Put G12 back in, turn on to look at something.
Hear a pop/crack and a burning smell. Turn it off and look by smell and bam, a resistor that went boom.
That'll be getting replaced.. in the meantime. Anyway to know...
Moved on to the next part of the logic diagram.
After cleaning, swapping, checking, IC checker etc I can confirm one of these IC is dead. G12 74LS161.
Moved it, cleaned it, checked underside and everything is good. No matter where I put it, it stays no signal on what is now G12 C1M pin 2...
I set it to trigger mode normal and stopped during capture and it looks a lot more like what I'd "expect" to see? If that's what you're referring to at least.
Data: edit: accidentall used wrong photo, inserting correct one, no different but is a stopped capture.
Address:
I keep thinking I'm crazy, but I clean the IC and socket again, sand legs again and bam clock on the CPU.
Amazing how dirty this board was!
Trying to track down where the hell my video is though!
I understood the timing logic diagram after staring at it for a long time a bit more, looking up...
Nice to know I was reading that correctly then!
Thank you for the explanation.
E7 is a simple 74LS00
So 12 and 13. Reseated and cleaned the socket again.. and...
Guess who has a 2mhz clock signal!
The 6502! WOO!
I think my ground might have been messed up to be honest. Too tired + trying to properly do things I guess doesn't go well.
So ignore my troubleshooting in post #123. I am so sorry folks. Silly mistakes intensify.. I knew 60hz waves didn't look right. Especially such large ones. Darn auto...
Went down a small rabbit hole on this one too.
If I'm reading this correctly, the logic prom is sending a signal to D5 -> E7 -> A11 -> PH0 which is the input on the 6502
Starting from the F7 pin 13 PROM:
This carries exactly to E7 pin 8.
Then the moment it reaches A11 pin 2 it turns...
Note to me in the future. Don't post results until you've re-seated and cleaned chips / sockets ;)
10 and 11 are both now 1.19mhz a piece. False alarm there.
Guess who has a new osciliscope that can pick up MHz, replaced a crystal and now gets 14.3mhz on pin 5 B13.
This guy! Wooo!
Off to find the rest of the brokenness in this machine.. pin 5 matches basically what 6 and 8 see for output (expected 14.3mhz)
Pin 12 is sending out 7mhz, good
Pin...
Hope yours are in better shape than mine ;)
Mine is just a love project at this point to save a rare old machine. I'm too far in (too much money in!) to not fix mine.
Here's to hoping you get the twins working and no big hiccups, like no video!
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