hints & tricks in no particular order
09/03/2025
I'll summarize what I learnt while working on 3 different T4400, 2 of them being T4400C and 1 being a T4400SX (with a "last gen" plasma screen no less!) Power supply The power supplies on all three of them needed a recap, as the laptops would not start otherwise (or sometimes start and stop suddenly). The caps are […]
09/03/2025
I expected it would be as easy as removing the batteries -- which is a must anyway on those old laptops because battery leaks are just another name for time bombs. Surprisingly for tech that old, the password doesn't seem to be stored in volatile memory. Let's dig! In the maintenance manual, it is said: Deleting the […]
02/11/2023
I had the misfortune of plugging this card halfway without realizing it, and to launch 3C5X9CFG to change its base address and IRQ. While flashing seemed OK, the card would then fail the EEPROM Vital Data Test, meaning corrupted EEPROM content, and a card that would no longer work properly. The EEPROM not only stores […]
11/08/2023
Every year or so, I try to run all the machines in my collection. As can be expected, the failure rate is going up every year, and there is not always an obvious "recap" fix. Sometimes, however... The HP OmniBook 430 is a nice little machine featuring some nice additions such as MS-DOS on a ROM and a tiny integrated […]
08/08/2023
Finally got a Spectrum +3 that was not outrageously expensive. Of course, in such case, it is safe to assume it won't work properly. I was not disappointed. The computer would display garbage characters on screen, which is a good sign. This means power, clock, CPU and video are just fine. This usually indicates some […]
13/05/2023
The "hard disk on ISA" card was a trend in the late 80s. I've got one sitting there for years. The reference on the ISA card is WDC 61-000347. The HDD itself is a WD93028-X manufactured in September 1989. It does sound like it could work i.e. no weird noises, spinning OK, heads moving OK but the controller decides that […]
18/08/2021
This KB is taken from some old microsoft archive, mirrorred on https://jeffpar.github.io/kbarchive/kb/066/Q66530/ Back in the ancient MS-DOS days, If you did not SYS right after FDISK and FORMAT, you could well end up with a "No Room for System on Destination Disk" error. In one case, it turned out I had to use a 4.0 […]
25/04/2020
The Tandy 1000SL is a neat XT compatible with a few tricks: advanced mode with 16 colors and a sound chip! Unfortunately, it only has 576 KB of available base RAM. So the trick is to find a MS-DOS with the best features for the lowest RAM. So I decided to make some tests: Total Reserved Used Free MS-DOS 3.20 570 454 44 […]
04/06/2017
The Toshiba Libretto 50CT originally came with Windows 95. It was not meant to be used with MS-DOS, and it does not have a hardware volume control. The Libretto uses an OPL3 sound chip that is Sound Blaster compatible—or perhaps the other way around, since Sound Blaster uses OPL3. However, compatibility does not extend […]
19/03/2017
I got a Compaq Portable III for very little money, mainly because it was considered dead. Disassembling, cleaning, and reassembling it somehow brought it back to life, with the exception of the CMOS battery and the floppy drive. I would not usually mention the CMOS battery, because it is obvious that batteries this old […]
13/03/2017
There are many Floppy Drive USB Emulators and not all are equal. Here is a list of GOTEK models: Formatted capacity 1.44MB : SFR1M44-*** 1.2MB : SFR1M2-*** 720Kb : SFRM72-*** Cables IDC34pin+4P power plug IDC26pin withour additional power FPC26 flat cabel 1.0MM pin distance use mdoel SFR***-**26 FPC26 flat cabel 1.25MM […]
13/03/2017
25/02/2017
I've been intrigued by Ret0bright for some time. This magic cooking recipe makes your old yellowed plastic computers like new again. It is not very clear what the consequences of the treatment are, since it involve chemical reactions and interactions with light and oxygen. The recipe is a bit complex though, but I […]
28/01/2017
I recently got a Commodore SX-64 to play with. Problem; the floppy drive, a Commodore 1541 was working a bit too randomly to my taste. Luckily, it is quite to find good advice (but also bad one) on the vast internet. It came out to be a problem with the drive spindle clamp mechanism. I found a very useful forum post […]
04/06/2016
Just a reminder of some of the vintage HDDs I still use... Conner CP3044 (40 MB) BRAND MODEL SIZE CYL HDS SECT WPCOMP LZONE TYPE WHERE? LINK CONNER CP3044 40 MB 980 5 17 0 980 ATA Specs CONNER CP2121 120 MB ATA Compaq Contura 4/25 PDF · Specs TOSHIBA MK4025GAS 40 GB 16383 16 63 0 16383 ATA-100 Specs
03/04/2016
03/04/2016
Title says it all :) I wanted to build a serial loopback plug compatible with the ancient CheckIt diagnostic tool. It wires serial inputs to serial outputs so that the port may be tested. There is more than one way to wire up a loopback plug - but this is the most common. Pinout front view: From Pin Pin To CD 1 6 DSR […]
23/11/2014
05/11/2014
10/05/2013
I got my hand on a 2005 computer which needed some fresh OS and a bios upgrade. The PC didn't have a working floppy drive but could fortunately boot on USB (which is not a given on older computers). The trick was to get a USB stick with a bootable FreeDos on it. It was quite easy! Use gparted to create a single FAT16 […]