Hardware – Ask Notes

September 4, 2018

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” 😉

August 31, 2018August 31, 2018

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:”

Perfect packaging :) — Perfect packaging 🙂

And here is the result:

March 30, 2018March 30, 2018

Sony Ericsson that have tx-rx connection

Sony Ericsson that have tx-rx connection:

2218z,
A2618s, A2618sc, A2628s, A2628sc,
F500, F500i,
J200c, J200i, J300a, J300c, J300i,
K300a, K300c, K300i, K500c, K500i, K506c, K508i, K600, K608i, K700, K700c, K700i,
P800, P802, P900, P908, P910a, P910c, P910i,
R300d, R300LX, R300z, R310s, R310sc, R320s, R320sc, R380e, R380sc, R380s, R380WORLD, R520LX, R520m, R520mc,
S700c, S700i, S710a,
T200, T202, T20e, T20ec, T20s, T20sc, T238, T28s, T28sc, T28z, T28WORLD, T290a, T290c, T290i, T292a, T29s, T29sc, T300, T306, T310, T312, T316, T39m, T39mc, T60c, T60d, T608, T60LX, T610, T61c, T61d, T616, T618, T61LX, T61z, T628, T62u, T630, T637, T65, T68, T68i, T68ie,
V600i, V800,
Z1010, Z500a, Z502a, Z600, Z608, Z800i.

Pinouts:

for J200i, J210i, J300i, K300i, K700, K700i, S700, S700i, F500, F500i, K500, K500i, T616, T628, T637, P800, P802, P900, P908, P910, T200, T202, T226, T226s, T230, T238, T290, T292, T300, T302, T306, T310, T312, T316, T20, T28, T29, T36, T39m, T39mc, R520, R520m, R520mc, T65s, T60c, T62u, T68i, T68m, T68mc, T68ie, z1010, T100, T102, T105, T106, T66, T600, R600, R600s, R600sc, A2618, A2628, A3618, Z200, Z300, Z500i, Z600, Z608, Z1010, S700, V600i, V800

bottom Pin	Name	Description
1	ATMS	Audio to mobile
2	AFMS/RTS	Audio from mobile/RTS (connected to GND in cable?)
3	CTS/ONREQ	CTS/Mobile Station On REQuest (connected to GND in cable?)
4	data in	Data to mobile (Rx). (Tx for K300i)
5	data out	Data from mobile (Tx). (Rx for K300i)
6	ACC in	Accessory control to mobile. Used as Rx in some models (i.e. T68) for flashing.
7	ACC out	Accessory control from mobile/handsfree sense. Used as Tx in some models (i.e. T68) for flashing.
8	AGND	Audio signal ground + 0V reference
9	flash	Flash memory voltage + Service (shorted to pin 11 in service cable)
10	DGND	Digital ground
11	Vcc	DC + for battery charging + External accessory powering

Pinout by Cruiser team:

Pin	Signal	Description
1	ATMS
2	AFMS
3	CTS_ON
4	DTMS
5	DFMS
6	CTMS
7	CFMS
8	AGND
9	VPPFLASH
10	DGND
11	DCIO

CTMS stands for Control To Mobile Station; CFMS stands for Control From Mobile Station; DTMS stands for Data To Mobile Station; DFMS stands for Data From Mobile Station

Standard cable is Sony Ericsson DCU-11

The (Tx)&(Rx) are reverse for K300i model, you must connect CTS & DGND together on board and connect the common wire to CTS(Pin3) in phone connector. If your cable is working fine then dont change it.