fl42v

So, yet another "if you're in the middle of nowhere and can't/don't_want_to wait for proper tools to arrive" kind of post.

Firstly, there's pico-serprog with quite good instructions from the libreboot project. Unfortunately, it didn't want to detect the chip at all in my case (in hind sight, likely due to the board pinouts being different between my board and a regular pico and them providing pico pins and not gpio numbers)

What worked, albeit rather slowly, was pico-dirtyjtag. If using this one, the connections are as follows:

• cs - gp19
• miso - gp17
• mosi - gp16
• clk - gp18
• gnd - gnd
• 3v3 - 3v3

The chip pinouts can be sourced from the libreboot guide/a laptop schematic/ic datasheet. Flashing with sudo flashprog -p dirtyjtag_spi -w rom.rom (or flashrom instead of flashprog). It may complain that there are multiple definitions matching the chip, in which case you manually choose one of the mentioned with -c (in my case -c W25Q32FV and -c W25Q64BV/W25Q64CV/W25Q64FV for top and bottom chips respectively).

Also applicable to stm boards with the main dirtyjtag repo.

So, I've dug up my corebooted t440p and decided to check if it'll work with the battery from my t480, and it did! Well, sort of.

Since coreboot also replaces the embedded controller firmware (mb sometimes they keep blobs of it, idk, but certainly not in case of t440p), we won't get those nasty "battery not supported, pay me" messages even if they've changed the verification since then.

However, I suspect some batteries may be unprepared for the power draw of earlier models. I've tested it on 2 batteries, one was a 22wh → 72wh conversion with BMS built on top of a cheap controller with rather unpleasant feedback from battery repair people; the other one was a more trustworthy 72wh clone powered by bq8050. The latter one worked ootb, while the former somewhat worked: fine in uefi, fine in grub, drop voltage to 0 as soon as the os starts loading → poweroff. If the power supply is plugged in during boot, the battery works fine (may drop voltage again under load, haven't tested it myself).

Soo, basically the use case is that you can try to retrofit the guts of a newer battery into older thinkpads if those run core/libreboot.

I've replaced cells in my fake battery a few days ago, and while recalibrating the bms I noticed what looked like it trying to overcharge the cells -- the voltage went up to above 12.6v and stabilized at around 12.9 (which amounts to ~4.3v per cell and is 0.1v above what cell manufacturers generally recommend). Idk if that's the intended behavior or clone manufacturers trying to shorten the lifetime of said batteries, so if the owners with genuine batteries can provide that info, I'd really appreciate it.

On linux, you can check this with cat /sys/class/power_supply/BAT*/voltage_now (as your usual user, those files are world-readable); not sure about windows, tho.

Out of curiosity, I've been watching a few restorations of those spectrums, and I've noticed the keyboards having a rather peculiar construction, judging by today's standards. They have 2 springs, the small one, as far as I understand, presses the membrane layers together, and the larger one returns the key into neutral position once the key is released.

I personally haven't used any spectrums, yet I've encountered the very same construction on a keyboard of a Russian clone of said machines (namely, zx atas), and to this day I haven't touched anything worse... The only way I can describe it is like trying to type on a piece of raw meat.

So, if anyone here had a chance to type on the original spectrums, was it this bad? I suspect otherwise since I haven't heard of crowds of people requesting PTSD treatment, but the whole thing still somewhat bothers me 😅

Just thought I'd share. Probably nothing new or fancy, but may help some of you find a way to repurpose devices that aren't worth repairing into home servers or something: e.g. op5 I've used has better CPU compared to raspberry pi 4, can run linux (postmarketos, albeit with some caveats), and costs less if bought with broken display (or nothing if you have one lying around)

Decided to share an older "project" of mine - ms sculpt wireless to wired conversion (also, it runs qmk, so we get all its features). A sensible person would order a custom pcb (such projects exist on the web, take a look if you're interested), but I went with removing all the components except from the ribbon cable connector, sending the PCB smooth, gluing a piece of discount card to isolate the traces, gluing a Chinese rp2040 on top, and wiring all the necessary traces to it. No, it wasn't fun. Yes, it works.

Bonus: when I disassembled it now I found out the type-c wasn't soldered well and decided to separate from the board:

So, here we go: using phone as a poor man's microscope (note: also, still works)

The end result kinda doesn't give it out, so whatever (insert your frontend -- backend jokes here)

x-post from tg: https://t.me/theaftertimes/15396