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HP 9895A Part 2: Epic Controller Board Repair (and a
HP 9895A Part 2: Epic Controller Board Repair (and a transparent chip surprise)
#9895A #Part #Epic #Controller #Board #Repair
“CuriousMarc”
We restore more HP 9895A dual 8″ diskette HP-IB drives, but these will be way more challenging. We’ll need a full on logic …
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HP propreitary protocol: Am-I-go?
I'm not a dumb guy, but I'm also not the brightest bulb in certain rooms. This room simply makes me feel inadequate in my technical knowledge; completely and utterly. Master Ken is the kind of guy that is just so smart that he's socially awkward. I revel in the time when you feature Master Ken. It's just fun to listen to him explain things. A curious question I have – are common life items as easy for you guys? Like if you had to replace a clutch or change oil or rotate tires? Do any of you cook well? I just imagine you guys being perfect at nearly everything you touch. I'm a former (recovering) perfectionist. Once I learned what I was, I realized that it was very debilitating. I always leave an imperfect mark on my projects as penance for abusing myself all those years.
@28:52 – This very thing happened to me at the Staind/Seether concert Wednesday night. I went to kneel down and my knee overextended and collapsed underneath me. I ended up doing a small roll across the carpeted club level. By the time I got back to the hotel at midnight, i had a balloon for a knee and walking was hard. It sucks getting old.
"The Input Buffer shall be equal to or greater than zero in length." β IEEE 488.2 apparently feeling the need to explicitly exclude the use of negative-length buffers
most entertaining!
Great analytics and repair. Maybe try to insert a smart buffer to that bad output line, Could be slightly logic voltage levels output is bit off, so Z80 see a 1 instead of a zero. I think if you probe it, you see its out of logic level specs. @ "Master" Ken, thanks for the chip inside tour.
Wow! Thank you!
You guys just astound me, I so enjoy watching you get stuff on its feet again.
This is soooo impressive!
I love seeing the HP 16C on the desk, hopefully helping out!
Really amazing work, Marc and the Marc-o-nauts.
Bringing out the logic analyzer. — meh
Bringing out Ken and Eric. — HERE WE GO!
Could I please get the HP85 test code for the drive? I wanted to run it on mine.
You guys are fantastic. Giving the "shoulders of giants" a big leg-up!
I just want to say that I got my "My other computer is an IBM SYSTEM/360" T-shirt today. I don't think I know anyone who will get the joke, but I do! π
Eight drives.. time to set up RAID 60 on them! π
"10 beginner programmers' mistakes: syntax error, undeclared variable, off-by-one error."
Nice work! Always happy to see you recombobulate vintage tech to a good working order.
That chip looks extremely complex, I couldn't make anything meaningful out of it. Ken is a true Sheriff of Electronics, ha! And again, I hope I learned something.
πππππ
Neat, neat !!
Beer, chicken wings, and 40 minutes of @CuriousMark
Man, what a night!
That FIFO looks like space invaders.