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MHz display panel circuity ???

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First post, by Spotted Cheetah

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Does anybody remember to those old PC cases which had TURBO button and a small two digit panel showing the speed of the PC?

I got one such panel, and as i liked those much, i built it in in one of my old PCs. It works fine, switches between "LO" and "HI". Now the "problem" is that i found that on this panel's back i found tons of jumpers with which i played around a bit and found that they are for setting up the display of this panel 😀 - but i have no idea how they actually behave... Maybe with trial and error i could figure out, but if for some reason any of you knows how that circuity behaves, it would save me a lot of time. I just wish to change it's display for the sake of the thing 😀

Maybe wrong topic, then sorry, but i could not find any better place for it...

If nobody knows after i tried those through i may give you the behavior (if i not destroy the poor panel...) - of course only if i feel i more wish to do it than how i fear of destroying the poor circuity, and if any of you is interested.

Left this dictatoric junk. No. IV.

Reply 1 of 13, by 5u3

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Yeah, these were the gadget you had to have on your case back in the days... 😁

Actually setting them up should be quite simple (depends on the circuit of course, but they all were wired up in a similar (cheap) way.

Most times they are coupled with the turbo switch, so the thing has two states: Turbo on or off. Each of the jumpers corresponds with one segment on the 7-segment display and determines if it should light up on a given state. Remove all the jumpers first and hook the thing to your mainboard. Then try placing a jumper and check which LED segment lights up. If nothing lights up, do not place the jumper there. Continue until you have the figure you want. This being done, toggle the turbo switch and repeat the process for the other state.
There are some fancier models where the above method does not work. These usually have two rows of jumpers and can only display numbers (so you can't define new "chars" on the segments). In this case the jumper positions represent binary numbers set in powers of 2, so the first jumper means 1, the second 2, then 4, 8, etc... The set values are added to determine the number displayed.

Reply 2 of 13, by Spotted Cheetah

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Thanks 😀

I already figured out that on mine for each led (i mean each line) there are three possible jumper positions (or to not short - circuit anything at all): one will turn it on in "hi" mode, one in "lo" mode, and one in both. The placement of these states appear to be somewhat weird (So not as excepted that each line follows the same scheme, they appear to be "random"), while some jumper placements reversed the hi/lo state.

I just fear a bit of that what if i accidentally place a jumper that way that i short - circuit the thing so make the panel diing... Although now thinking it again it not looks like possible if it was set up wisely since then i may just place the jumpers in a way that i just connect two things what where connected already (so does nothing). I guess i can follow your method and pull everything out :p

The most stupid thing is that this gadget for me just hangs on a few wires out of the case (like my PC Speaker :p ) as there is no place for it on the case... Maybe i will stick it somewhere on the PC - or maybe it is just good as it is 😁

Left this dictatoric junk. No. IV.

Reply 3 of 13, by HunterZ

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My Wyse 8MHz 286 actually had a full dot-matrix LCD display on the front that was big enough to show a single line of about a dozen characters or so. There was even a program included that let you display your own strings of text on it. Normally it just showed the CPU speed and I think the current time.

Reply 4 of 13, by Spotted Cheetah

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Here is the circuit, i could figure it out on my own... Although i could not find out what can turn on the dots (they are always off, maybe they are not even wired in).

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Left this dictatoric junk. No. IV.

Reply 5 of 13, by HunterZ

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It's likely that the dots are not wired to the jumper-board, but if you can get to the pins on the back of the 7-segment display then you may be able to power them that way (you may need to add your own resistor or wire through the one on the jumper board though).

Edit: Here's some info on the display itself before the jumper board is added: http://www.play-hookey.com/digital/experiment … en_seg_led.html

Reply 6 of 13, by Spotted Cheetah

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I think i understood what the article meaned - based on how the thing appears to be assembled it seems to be possible to solder the display panel out of it and then i would see which connector leads where from it. But i have not got a proper equipment to do this. Maybe if i can catch on which connector it gets the power (i think short - circuiting the mobo would not be a nice thing through that panel) by studiing the wiring (so if it is not hidden by some other part or the panel itself) with some trial - and - error i might get which connectors are for turning on the dots.

The dot - matrix gadget would be good for me with the time as i altered my Windows disabling it's end - user interface (with the Start menu) to make it loading and functioning much faster, so i can not see the clock (Except if i give a "time" command in a DOS box) 😀 . But then how to get the system time?? - Huh !? - maybe with building some own hardware 🤣

(By the way are home - made hardwares possible with WinXP? Like those built by train - modellers to control their trains using the PC? A lots of years ago i heard about such...)

Left this dictatoric junk. No. IV.

Reply 7 of 13, by samudra

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Got this with a new old stock AT case I recently bought.

Maybe it is of use to anyone (besides Amigaz, hehe).

caseledpinout.png

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This is not a QEMM error.

Reply 8 of 13, by markot

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This is already an old thread and I have a question related to the instructions posted by samudra, so I will ask here.

It seems clear to me how numbers 16 and 120 are related to each other in the big table, but how are the digits 1 and 2 configured to the pins above?

For this combination there are 2A 3B 1C 2D 2E 2G and I don't understand how the jumpers should be set.

Reply 9 of 13, by NJRoadfan

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The first two rows of pins controls the right most digit ("ones"), while the last two rows control the center digit ("tens"). The hundreds digit is controlled by the H pins on the sides.

One of my cases came with instructions for that block, and shows shaded pins as an example.

http://www.minuszerodegrees.net/led_speed_dis … 568%20S305H.jpg

Reply 12 of 13, by badmojo

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Intel486dx33 wrote:

Is there already a thread with the different types of LED displays and the jumper manuals ?

That’s rich coming from the ultimate un-googled questions thread starter 🤣

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