Notices by Tube🌞Time (tubetime@mastodon.social), page 2

this was great for a while, but on July 16, 2022, Excess Solutions opened their doors to the public for the last time. and on that day, I decided to get myself a guaranteed supply of chips, and two of my friends were totally down for it.

most of their inventory got sold to Excess Solutions (located in San Jose).

if you've been wondering why i haven't been posting as prolifically this year, this is the major reason.

over the last few months, i spent hours and hours carefully packing chips into separate drawers. by putting multiple part numbers into a single drawer, i was able to reduce it down to just 12 cabinets.

after separating out my share of the parts, i stuffed them into thousands of plastic ESD-safe bags, each labeled with a sharpie and stored in a moving box.

HSC originally used black ESD foam which degraded horribly over the years. i hate that stuff. i hate the sour smell it gets when it degrades, and i hated having to pick hundreds of chips out of crumbling, decaying foam.

* yes, many of the drawers (for MOS parts) have ESD protection in the form of an aluminum foil layer. i applied it with glue and this custom 3D-printed jig.

OK some answers to questions you might have:

* i don't want to run an electronics business so i'm not planning to sell any. doesn't mean i won't give parts to friends occasionally.

* yes, i have a catalog of parts organized in a spreadsheet, which makes it much easier to find things

so i did something totally insane. the local electronics store was closing down and so i (and two friends) purchased THEIR ENTIRE STOCK OF INTEGRATED CIRCUITS. and today i finally finished organizing my share into these 12 cabinets. 🧵

ahh yes, the little known 3M Sandblaster Pro

@mntmn FAT12 vibes

i've got a new teardown up: this time it is the Thinkpad 700C battery pack. it's ultrasonically welded shut, but i figured out a pretty good way to open it up.

https://www.ifixit.com/Teardown/IBM+Thinkpad+700C+Battery+Pack+Teardown/176472

what's interesting is that the board hosts a microcontroller. the schematic lists it as a "6510" which makes me think it is 6502-based.

it would be nice to be able to repair the logic boards. a schematic exists, which is quite helpful.

I'm tinkering with some old hard drives, like this ST-251.

you can find good info here: https://bitsavers.org/pdf/seagate/mfm/ST-251/

another version of the board has the EPROM footprint populated, and the chip is marked R6518AJ, which is definitely a Rockwell microcontroller. the firmware has already been dumped.

on my board this is the part marked 80118-501
R1512-11

and it has the Rockwell logo, making me think it is something from their R6500 series of 6502-compatible microcontrollers.

oh yeah. i've mapped it starting at address 0x3000 but the hardware maps the ROM chip in starting at 0x0100, where it just gets aliased all the way up to 0xFFFF. the absolute jump addresses located in the vectors at the top of the ROM refer to addresses starting at 0x3000, so i'm just using that.

this definitely looks like 6502 code. time to pull it into Ghidra.