486 Speed Display Panel Wiring Help Needed

[RJBJR]

Hello All,
I am building a 486 computer and am using an old 486 case to house everything. The 486 case has a speed display that looks like it was never hooked up as there are neither wires in the case nor a power wire for it from the power supply.
I would like to hook up the speed display but I am clueless about the wiring.

There are two 4-pin headers on the speed display PCB.
From left to right, the first header is labeled pin1=?, pin2="+"(positive), pin3="-"(negative), pin4="S". The second header is labeled pin1="L" , pin2="R" , pin3="H" , pin4=?. The question mark means no markings.

I am guessing the first set of pins with "+" and "-" are for 5v power in. As for the other pins on either header I have no idea.
Included a pic of the headers and the face of the speed display.

Any help appreciated, Thanks.

 

[mbbrutman]

Hi Russ,

These things are notoriously hard to setup - they were all different and there is not a good convention. The basic idea is to jumper LEDs to get them to turn on. Supply the power as you expect, and then experiment with jumpers to make it light up the segments.

Some of them are capable of displaying two different speeds - your header might have an input to select that. I'd get one working and be happy with it, unless you like puzzles.


Mike

 

[Ole Juul]

There was someone on this forum who had "special skills" with those. Perhaps see if a forum search can bring up the thread.

 

[RJBJR]

Hi Russ,

These things are notoriously hard to setup - they were all different and there is not a good convention. The basic idea is to jumper LEDs to get them to turn on. Supply the power as you expect, and then experiment with jumpers to make it light up the segments.

Some of them are capable of displaying two different speeds - your header might have an input to select that. I'd get one working and be happy with it, unless you like puzzles.


Mike

Howdy Mike,

Thanks for the nudge, I put power to it and started playing with the jumpers. Not sure whether I have the proper switch on the case to make the display work properly, there was a good quantity of hot glue applied to the back of the turbo switch which has covered the 3 pins that would, I suspect, feed the turbo display power for changing between turbo or non-turbo mode. I'll have to clean that or maybe get another switch from a different box to give this a chance to function as designed.

 

[RJBJR]

There was someone on this forum who had "special skills" with those. Perhaps see if a forum search can bring up the thread.

Thanks for that, it took some digging to find that good info. For future reference http://www.vintage-computer.com/vcforum/showthread.php?10217-Mhz-display-help

The link to http://www.pcmech.com/article/how-to-program-your-system-case-display/ put me on the right track and now I understand what wiring is needed to make it work.