Jaan's Tech Logs

3com_etherlink_iii

Anonymous (anonymous@undisclosed.example.com) — 2024-05-03T05:26:19+00:00

3Com Etherlink III is one of the most popular network cards for retro PCs. It has a lot of versions and almost all of them work very well. Some cards have a place for a ROM chip that can be used, for example, to load an XT-IDE BIOS (tested). See also:

592125sc-2

Anonymous (anonymous@undisclosed.example.com) — 2024-11-25T10:32:40+00:00

592125SC-2 was an E27 LED lamp that didn't give out light any more. I opened it, unfortunately I had to break the aluminium at the edges. The type of lamp is written to the side I tested each LED separately with multimeter in diode mode, they were fine. (Not all multimeters go up to the voltage of the white LEDs)

a64-olinuxino

Anonymous (anonymous@undisclosed.example.com) — 2024-03-03T09:08:10+00:00

A64-OLinuXino is an open source hardware project by Olimex. I have used different versions of this board. I've used Ubuntu and Debian as the operating system. I have compiled the kernel for some joystick drivers. I have had to make custom device tree overlays to get a faster I

aztech_radio_card

Anonymous (anonymous@undisclosed.example.com) — 2024-03-19T18:06:25+00:00

I have this Aztech ISA FM radio card that I haven't managed to get working. It seems to be an Aztech SG (Sound Galaxy?) FM Stereo Radio Card. Other text on the card: AZSC62019784, 800-W99531-A12, I38-MMFM601 I have tried FMTuner application without luck.

bash_scripts

Anonymous (anonymous@undisclosed.example.com) — 2024-04-14T17:35:05+00:00

I use a lot of Bash scripts in Linux. These are a few examples. checksize.sh checksize.sh a script that checks whether an image file is certain width & height, then takes action (in this case, removes the file). Can be used together with find. Remove is commented out, because you may want to use the script for something else. The script uses

beaglebone

Anonymous (anonymous@undisclosed.example.com) — 2024-04-06T08:49:29+00:00

BeagleBone Black and Green They are mostly the same, Beaglebone Black has HDMI, Green doesn't have it, but has something called Grove connectors for I2C and UART. Beaglebone has two PRUs which are basically very fast microcontrollers. I've used them for near real-time sound acquisition. I followed the tutorial from this website:

covox_speech_thing

Anonymous (anonymous@undisclosed.example.com) — 2024-05-11T18:41:51+00:00

I have tried a DIY version of the Covox Speech Thing. The driver that worked in Windows 95 was from Vogons: Covox Speech Thing!!!. Covoxwin.zip from there worked. (Only the LPT driver is needed) I think I had to disable my other sound card (Windows 95 - disabled loading sound card on boot) to make the Covox work.

ds12b887

Anonymous (anonymous@undisclosed.example.com) — 2025-05-12T13:48:56+00:00

DS12B887 is a battery-backed RTC (real-time clock) that was used on motherboards during mid-1990s. When the internal battery dies, it doesn't keep time or BIOS settings any more. I have managed to drill one of these RTCs open and resoldered + (plus side) wire to use an external battery (like CR2032).

ezcap_280h

Anonymous (anonymous@undisclosed.example.com) — 2025-06-26T08:59:07+00:00

EZCAP 280H problems Fault: A HDMI to USB recorder had an 12V adapter plugged into its 5V supply port. A total of 3 power converters were destroyed, one for 3.3V, one for 1.8V, and one for 1V (exact value unknown). Two of them had a text “A15T”

fan4800in

Anonymous (anonymous@undisclosed.example.com) — 2024-04-27T10:07:41+00:00

On some ATX power supplies from 2000s, a chip called FAN4800IN was used for PFC+PWM control. On at least one supply, I had to replace the high voltage electrolytic capacitor and maybe some other components, before I got the whole power supply to work again.

flashing_eproms

Anonymous (anonymous@undisclosed.example.com) — 2024-05-03T05:25:47+00:00

I managed to erase an EPROM (NM27C512Q) using sunlight. I left it outside for about a week, after that the chip was empty. Then I put XT-IDE BIOS onto it. First, as the EPROM is 512 kbits (64 kBytes) and the 3COM 3C509 network card has up to 32 kBytes support, I made a file that contains the BIOS 2 times.

forum_bookmarks

Anonymous (anonymous@undisclosed.example.com) — 2024-07-08T11:37:14+00:00

Balena * * Vogons * * Seeed Studio * Pingviin.org

huawei_hw-120200e6w

Anonymous (anonymous@undisclosed.example.com) — 2025-05-23T18:31:24+00:00

I have many times tried to repair the Huawei 12V 2A power adapter HW-120200E6W. It was used with some Huawei 4G router. It had failed randomly. Sometimes it worked, sometimes it didn't. I did stress tests with 1.8A of current for ~1 hour. Sometimes it failed, sometimes it survived.

installing_linux_from_linux

Anonymous (anonymous@undisclosed.example.com) — 2025-05-23T18:06:22+00:00

Attention! The following doesn't work with Secure Boot enabled. You could temporarily disable it do make an upgrade and then re-enable it. Haven't tested, but should work. To install a new version of Linux, I usually just download the kernel and the initrd from network installer media. I copy it to /boot (new files I rename to something like /boot/newlinux and /boot/newinitrd)

lenovo_g34w-10

Anonymous (anonymous@undisclosed.example.com) — 2025-07-02T13:20:10+00:00

Lenovo G34w-10 This curved display just stopped working. I opened it and saw that the so-called T-CON board wasn't outputting any voltages. Most probably the main chip (SM4191A) was dead, but I still ordered a new board. After replacing the board, the monitor started to work.

lg_32lg2100

Anonymous (anonymous@undisclosed.example.com) — 2025-09-29T18:34:20+00:00

This TV had a broken screen, not repairable. These parts are sold on Ebay. Backlight was still functional. Power supply model LGP32-09P Mainboard

makita_dc18sh

Anonymous (anonymous@undisclosed.example.com) — 2025-09-28T17:30:41+00:00

The dual charger Makita DC18SH suddenly had 1 side faulty. No lights came on on that side any more. The controller OB2512 seemed to have a jumping voltage, but on primary side things seemed ok. On the secondary side of the transformer, immediately after it, diode D9 was shorted and had to be replaced.

notes

Anonymous (anonymous@undisclosed.example.com) — 2025-05-30T14:15:30+00:00

Windows 11 installation Installing Windows 11 when the only thing you have is dd in Linux (spoiler: dd will not work) Useful link was: In Bash, for 7z commands, ! needs to be replaced by \! and quotes can be removed. Make 1 FAT32 partition on USB drive, make it active. 8GB USB drive recommended. Use fdisk and mkfs.vfat. After that, mount the FAT partition to /folder/to/usb and then do this:

opl3lpt

Anonymous (anonymous@undisclosed.example.com) — 2024-05-15T08:58:13+00:00

I bought the OPL3LPT from Serda Shop: OPL3LPT It's an Adlib compatible add-on for PC parallel (printer) port. To make it work, I had to: * Make a AT keyboard to USB Mini power cable adapter * Download latest oplutil: EMM386 was needed. To load it, I had to edit config.sys on my

philips_40pfh4309_88

Anonymous (anonymous@undisclosed.example.com) — 2025-09-29T18:25:19+00:00

This Philips 40 inch TV (40PFH4309/88) was in restart loop. The loop was about 15 seconds, it showed briefly a TV channel name, then immediately restarted. First I thought it's the power board, but applying 12V from an external power source gave the same symptoms.

raspberry_pi

Anonymous (anonymous@undisclosed.example.com) — 2024-03-18T17:55:52+00:00

I have used following Raspberry Pi models: * Pi Zero * Pi Zero W * Pi Zero 2 W * Pi 1 A+ * Pi 1 B+ * Pi 2 B * Pi 3 A+ * Pi 3 B * Pi 3 B+ * Pi 4 B * Pi 5 I've used the Raspberry Pies mostly for data logging (USB-serial). I²C

samsung_ue55au7022kxxh

Anonymous (anonymous@undisclosed.example.com) — 2025-10-05T16:50:10+00:00

The Samsung UE55AU7022KXXH TV stopped showing a picture. Audio was fine. I replaced the T-CON board with a new one, I got a black and white picture. After ordering another one from Ebay, the picture is now fine and the TV is working. A picture of the non-working boards:

start

Anonymous (anonymous@undisclosed.example.com) — 2025-10-05T18:01:40+00:00

Here is a list of things that I have some experience with. Retro computers Old computers: * Toshiba T3200SXC (a 1991 portable computer) Old add-in cards, internal and external devices: * 3com Etherlink III Ethernet network card * Aztech radio card * Covox speech thing * DS12B887 battery-backed real-time clock *

terratec_tt1816

Anonymous (anonymous@undisclosed.example.com) — 2024-02-13T13:00:26+00:00

I have two of these ISA sound cards: TerraTec Pro Media TT1816-N V1.0 Drivers are Terratec Base1. Joystick/MIDI port untested yet. Speaker/line out output selectable with jumpers Works with my Toshiba T3200SXC in DOS, might encounter problems in Windows when left uninitialized in DOS.

toshiba_t3200sxc

Anonymous (anonymous@undisclosed.example.com) — 2025-12-29T12:17:57+00:00

Toshiba T3200SXC My T3200SXC Picture taken in February 2024. Specs * Portable computer from 1991 * CPU Intel 80386SX 20 MHz, slot for 387 math co-processor * Non-standard Toshiba BIOS, battery backed * 1 MB internal RAM, expandable to *16

ts-7260

Anonymous (anonymous@undisclosed.example.com) — 2024-03-18T18:03:56+00:00

Technologic Systems TS-7260 I have burnt one device because a jumper was in the wrong position when applying 12V. A very low power Linux computer * 4.5-20V in * Power consumption can be as low as 0.5W, maximum 2.0W * Temperature -40...+85 °C

ts-7800

Anonymous (anonymous@undisclosed.example.com) — 2024-04-26T08:12:38+00:00

TS-7800 by Technologic Systems Specifications: * Marvell MV88F5182 500 MHz single-core ARM9 CPU * 128 MB RAM * 512 MB onboard NAND flash * SD & MicroSD slots * 2 SATA ports * Real-time clock (battery is dead on devices that I have) *

usbc_bug

Anonymous (anonymous@undisclosed.example.com) — 2024-04-22T19:02:59+00:00

When a file called USBC plus some garbage is on your filesystem, you've encountered something called a USBC bug. This usually means that a USB driver, instead of writing some files to the filesystem, wrote the USBC command itself to the filesystem. Some people may think it's a virus, which it most probably is not.

what_drives_me_nuts

Anonymous (anonymous@undisclosed.example.com) — 2025-10-05T18:48:44+00:00

Here are some things that drive me nuts when I'm working with some software or web pages. * Ebay's false positive checks on sale listings * For example, parts / not working - this is too similar to a link. Use: parts OR not working. * “Text on the back says

x.exe

Anonymous (anonymous@undisclosed.example.com) — 2025-05-06T07:59:35+00:00

X.EXE. This is a DOS game made by an Estonian. It's a Xonix clone. The file The game executable (X.EXE) is only 8107 bytes. The executable is from October 14, 1992, and the binary contains a few sentences in Estonian (“Kollarv läks üle max.-i”