Blinker/Turn relay TBB44 schematic and lt-spice model


I have one of these in my old BMW R75/6 motorcycle. As I once had a short to chassis on one of the cables from the relay to the lamps the relay stopped working. After resoldering the (internal) relay and fixed with the contacs, the relay worked, sort of. The indicator lamp did only blink once or twice and then nothig. As I could not find any schematic or spare parts on the net, i decided to do some reverse engineering.
The 0.033 Ohm resistor in the schematic is actually a metal bridge going from the relay to the center connector to the right, see component-side. This metal bridge had become very hot and probably changed resistance, I do not know what the resistance was before the incident, so 0.033 Ohm is after. Anyhow by parallel connection of a suitable resistor Rtest with R10 (10 Ohm) the indicator lamp worked again. Note this resistor shall be selected so that the indicator stops blinking if one of the blinker lamps gets broken, if a too low value is used then this won't work.

relay connectors-in-back component-side foil-side lt-spice-schematics(jpg) lt-spice-model

Autostart for ATX computers that not support start at power on in BIOS


If you want to use an ATX computer for a firewall or fileserver or something else that you want to autostart after a power failure and the BIOS for the machine does not support that... what to do?
Here is a small hardware patch using a c-mos 555 circuit that can fix that:
board installation1 installation2 schematics(pdf) schematics(jpg)

Locate the +5V standby and a ground from the ATX power supply and tap in to those. Next you need to locate the wire to the power-button and tap into that. Then you should be all set.
The only drawback i know with this solution is that if the power outage is so short that the +5V standby does not disappear, then this circuit will not be able to start the machine.

Stackpointer - Datorföreningen Stackens organ

Gamla inscannade nummer + lite annat finns här.

About PDI/2:

The StackPointer article about PDI/2 from 1988.
A short .pdf presentation of microprocessors in servotechnology (in swedish).
Jörgen Städje writes about PDI in swedish and in english, far down.
The SAFA site is here.

Patched firmware 1.0q for the Yamaha CRW 2260

If you have modified your CRW 2260 to 4260 (4x) and want the latest firmware you have it here.
If you have not (yet) done that, look here for an instruction on how to do it.

The PDP11-emulator is here:

A sligthly modified version of Bob Supniks PDP11-emulator:

Connect to ELVIRA port 4000, login as user: 99,99    password=user


Operating system is RSTS/E V 8.0. The emulator is running on a AMD K6 300,
so the it is slithly faster than a real PDP11/73.

NOTE: disconnect is a bit slow after logout.

The ELVIRA homepage (some more stuff)

INIT.SYS Y2K patches to RSTS/E V8.0 and 9.2:

To allow RSTS/E to boot to a date after 31-dec-99 use this for V8.0-06, for V8.0-07 and forV9.2-10 with $ONLPAT.

Problems with SLOW RTL8029 based ethernet card?

Look here, it might help.