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Tube🍂Time

oh i should fix the backlight, which blinks on and off for some reason. time to take it apart!
2 May 2023 at 2:15 | Open on mastodon.social
101 comments
Tube🍂Time replied to Tube🍂Time

welp, looks like i missed a few electrolytic capacitors. check out all that nasty corroded fuzz on the nearby component leads!
2 May 2023 at 2:16 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

all cleaned up! i had to remove all those parts, add flux and reheat all the pads, scrub with IPA, and then put everything back in place. and replace the caps, of course.
2 May 2023 at 2:17 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

it lights up and stays lit, so i'll call that a win. (yes, the hard drive still isn't working, so it's not booting.)
2 May 2023 at 2:18 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

i just got the AC adapter for this! it came in from everyone's (not) favorite auction site. the listing conveniently forgot to mention that it REEKS of cigarette smoke. 🤢
oh well, at least it was cheap.
6 May 2023 at 16:59 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

even the inside smells like smoke. it's not an ultrasonically-welded plastic case (just held together with 4 screws hidden under the labels) so it's definitely not airtight.
6 May 2023 at 17:00 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

pulled the main power transformer for reverse engineering purposes.
6 May 2023 at 17:01 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

last night i reverse engineered it. the design is simple so it wasn't too hard. the files are here: github.com/schlae/Thinkpad700C
6 May 2023 at 17:02 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

it also explains the mystery "INPUT SIGNAL" pin on the old 4-pin IBM Thinkpad power connector. this pin simply increases the output current limit when it is pulled low by the laptop. it's because the power brick is also the battery charger, and when the laptop is turned on, you have to increase the current to compensate.
6 May 2023 at 17:04 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

anyway, isopropyl alcohol wipes and a bath in Simple Green has mostly taken care of the bad smell.

6 May 2023 at 17:06 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

now for that pesky docking connector: I've discovered that a 1.2mm PCB fits perfectly in the connector, so I made a set of two boards that stack and break out all the pins to 0.1" headers.
6 May 2023 at 18:37 | Open on mastodon.social
George Laskowsky replied to Tube🍂Time

@tubetime Please don't step on those! Lego is bad enough already

6 May 2023 at 18:38 | Open on mastodon.gamedev.place
Tube🍂Time replied to Tube🍂Time
math blasterson replied to Tube🍂Time

@tubetime Haha, that was actually my first thought when you started this thread. "Those are just dressed up card-edge connectors." Nice job.

6 May 2023 at 18:48 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

now you know why I need a working logic analyzer. these pins also go to the hard disk connector inside, which makes me think they are the internal bus. the trick is to figure out what they do.
6 May 2023 at 19:43 | Open on mastodon.social
Dustin replied to Tube🍂Time

@tubetime holy smokes you are really deep-diving on this one, well done!

6 May 2023 at 19:46 | Open on geekdom.social
Tube🍂Time replied to Tube🍂Time

next step is to identify control lines vs address and data
6 May 2023 at 20:01 | Open on mastodon.social
DrYak replied to Tube🍂Time

@tubetime when you manage ti document it, you're probably going to make a few hardcore ThinkPad fan happy.

Expect retro OPL2/3 sound card and joystick ports to appear.

6 May 2023 at 20:08 | Open on mstdn.science
Tube🍂Time replied to Tube🍂Time

starting to pick out a few lines. between the cursors is an extended bus cycle
6 May 2023 at 20:39 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

now I'm writing short programs in DEBUG to help me figure out which data lines are which.
7 May 2023 at 22:01 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

i've got all the address and data lines mapped out, and all the basic control lines. now to figure out the DMA lines...
8 May 2023 at 0:09 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

and that's 99% of it figured out. i haven't untangled which IRQ is which, and there are a small number of signals i don't understand yet. but this is functional enough to start building adapters. i'll publish this at some point.
8 May 2023 at 4:56 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

there are a few signals unique to the hard drive connector, so I'm figuring those out now.
9 May 2023 at 0:55 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

the unique signals are the card setup line (turns out this is slot 1 and the dock connector is slot 2), the high address bits predecoded, IDE style, and what seems to be a system reset line.
10 May 2023 at 1:05 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

the hard disk drive has a weird 60-pin AMP CHAMP connector (5176376-2) but that just gets wired to a 52-pin 2mm header. the pin wiring is 1:1 except for the last 8 pins which are not connected.
10 May 2023 at 1:07 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

it was surprisingly hard to figure out that AMP part number, btw. connector manufacturers constantly scrub all information about old products because who knows 🙃

10 May 2023 at 1:08 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

and yes, the hard drive is vaguely like IDE but it uses the Micro Channel bus instead of ISA. IBM called it DBA (direct bus attach) ESDI. this drive uses the POS ID code DF9F.

10 May 2023 at 1:11 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

i needed to figure out which interrupt lines were which, so i wrote a quick and dirty program to detect when an interrupt fires. then i manually triggered them by grounding each pin in turn.
11 May 2023 at 4:31 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

on to a few physical repairs! this corner got really trashed by the hinges, so i need to figure out a way to restore it.
13 May 2023 at 23:14 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

i've used a similar technique to repair an Amiga 500. the idea is to 3d print the missing piece.
13 May 2023 at 23:15 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

it's a quick 20 minute print even with a 0.3mm nozzle, 0.12mm layer height, and 100% infill.
13 May 2023 at 23:16 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

the next step is to carefully carve away at the plastic so that it fits well. small gaps are ok, there needs to be a little room for the glue.
13 May 2023 at 23:17 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

for the glue i am using JB Weld. a little excess is ok since i can file and sand it down afterwards. the locking forceps are clamping the plastic part to the metal tab i installed a few weeks ago.
13 May 2023 at 23:21 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

I'm also doing the other side as well where the damage was less extensive. unfortunately the DC-IN legend is damaged and the connector icon is half missing, so I need to figure out how to replace it. a water slide decal might work.
13 May 2023 at 23:24 | Open on mastodon.social
Cellivar replied to Tube🍂Time

@tubetime Paint pen and a steady hand? ;)

Your work is great to watch!

13 May 2023 at 23:36 | Open on furry.engineer
Darryl Ramm replied to Tube🍂Time

@tubetime All this is making me miss my old Thinkpad 701 Butterfly. Damn that keyboard design was so neat.

14 May 2023 at 0:02 | Open on hachyderm.io
Tube🍂Time replied to Tube🍂Time

the glue has dried. I'm not crazy about the fit but it is much better than before. it should look pretty good after I paint it, someday.
14 May 2023 at 21:34 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

the laptop was missing the modem cover so I'm making a new one. this design is supposed to slide in place, but I think the original was supposed to hinge down, and probably didn't have any openings in it.
16 May 2023 at 0:18 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time
Tube🍂Time replied to Tube🍂Time

oh wow i found documentation for the weird protocol used by the 2.5" ESDI hard drive!
19 May 2023 at 3:55 | Open on mastodon.social
Tube🍂Time replied to Tube🍂Time

a simple program should be able to retrieve these error codes. perhaps i can fix the hard drive?
19 May 2023 at 4:05 | Open on mastodon.social
lopta replied to Tube🍂Time

@tubetime I've seen 3.5" ESDI but never 2.5"!

19 May 2023 at 4:40 | Open on mastodon.social
George R. M. 🇩🇪🇺🇦 replied to Tube🍂Time

@tubetime for a second there I forgot these use the aptly-nicknamed "ThinkPad 700 drive". What a cursed thing it was, DBA-ESDI 2.5".

11 May 2023 at 8:44 | Open on mastodon.social
Glen Akins replied to Tube🍂Time

@tubetime My guess would be acquisitions and not caring about all the product lines of the acquired company. Good news is now that TE owns all connector manufacturers*, they won't have this excuse going forward. (*slight exaggeration)

10 May 2023 at 1:11 | Open on mastodon.social
Brad Bell replied to Tube🍂Time

@tubetime I like how they keep making the connector but change the names and numbers

10 May 2023 at 8:12 | Open on bitbang.social
bitsavers.org replied to Tube🍂Time

@tubetime

I started archiving catalogs from connector companies just because of that problem.

11 May 2023 at 4:54 | Open on oldbytes.space
Jeff Haluska replied to Tube🍂Time

@tubetime Haven't seen somebody do that in about 25 years.

8 May 2023 at 0:48 | Open on mastodon.social
Jeff Haluska replied to Tube🍂Time

@tubetime Time to invent a rubbing alcohol pressure washer.

6 May 2023 at 17:01 | Open on mastodon.social
ĸurth replied to Tube🍂Time

@tubetime don't say 'just screws' … bless the screws

6 May 2023 at 17:02 | Open on social.tchncs.de
FozzTexx replied to Tube🍂Time

@tubetime I once got something that was so bad that the things inside that were still sealed in the original shrink wrap reeked of smoke when I took the shrink wrap off. I ended up throwing away most of the items.

6 May 2023 at 17:01 | Open on mastodon.fozztexx.com
Jeff Haluska replied to Tube🍂Time

@tubetime You're taking good care of the capacitors they're growing in size! 😆

2 May 2023 at 2:19 | Open on mastodon.social
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