Removing supervisor password (SVP) on ThinkPad T42

Recently received two ThinkPad T42 laptops ( some company decided to upgrade its IT and were giving away them almost for free ). After turning them on got an 271 error and later was prompted to enter password.

It seems battery was dead on both of those laptops and when its dead, real time clock goes bananas and you are asked for supervisor password to set the clock again ( if supervisor password was set ).

Offcourse nobody knew anything about what password it was. So had to figure it out myself how to solve this situation.

On ThinkPad T42 SVP password is stored on EEPROM chip 24RF08. One thing that sometimes work and was reported by many T42 users is to short pins 3 and 4 of 24RF08, procedure:

  • Short pins 3 and 4 of 24RF08, keep them short
  • Tun on ThinkPad
  • Press F1 to go to BIOS
  • If asked for password press enter
  • Go to Security – Passwords – Supervisor password
  • Release shorted pins
  • Enter new password, save and reboot.

Then go to BIOS again and disable SVP password by entering the password you just saved.

Like they say – “it worked on my two t42 machines” 😉

ThinkPad T42 removing SVP
ThinkPad T42 removing SVP
ThinkPad T42 removing SVP
ThinkPad T42 removing SVP

ZX Spectrim 128 +3 composite video output and drive belt replacement

Did some work on ZX Spectrum 128 +3 I have. One thing was I wanted to make it work with small “TFT Color monitor” (for a car rear view). This monitor has a composite video input.

First I tried using CSYNK and GND signals for a composite video input. You get the video but it was terrible quality. It seems that “The 128 ZX Spectrums including the +3 (and +2A, +2B) have audio sound modulated onto the video, which reduces the clarity of the composite signal that is available at the modulator input.”(1).

Then I found this document – “Video fixes and video cables
for all ZX Spectrum 128K models”. There is a chapter on Creating composite video-out on a +2A / +2B / +3:

“Although the ZX Spectrum 128K heat sink model and the grey ZX Spectrum +2 have a composite video-out signal on pin 1 of the RGB connector, the ZX Spectrum +2A, +2B and +3 are missing this feature.
Instead of the composite video signal they have a dangerous 12V on pin 1 that will seriously damage your TV or monitor!
But you can add the composite video signal yourself, with the same fairly simple circuit as that is integrated on the heat sink model and +2.
The steps:
1. First remove the 12V from pin 1 by removing resistor R44 (should be the same for +2A, +2B and +3, and very close to the RGB connector).
2. Add this circuit:”

zx spectrum +3 composite video mod
zx spectrum +3 composite video mod

 

zx-spectrum-rgb-pinout
zx-spectrum-rgb-pinout
Perfect packaging :)
Perfect packaging 🙂

And here is the result:

zx spectrum +3 composite video mod
zx spectrum +3 composite video mod

 

 

Result
Result

 

 

The Shallows: What the Internet Is Doing to Our Brains

The Shallows: What the Internet Is Doing to Our Brains
The Shallows: What the Internet Is Doing to Our Brains

Recently have finished this book. From the times of Plato and Aristotle our brain and way of thinking is changing and adapting to our way of living. Every tool we use becomes a part of us, but also we become a part of a tool we use. Clock, written word, computers, world wide web. Everything we use changes us, changes how we think, changes how we remember things.

Its a good read that raises a lot of interesting topics.