controlling a old school led message sign HiTech "AS-0216" with a UNO

hi all, i got a old moving message led sign from flea market, the PS was missing so i got it cheap.
the processor on this unit is looking like a old 8080 processor. but i have better ideas for this.
i want to remove the control unit and replace it with a UNO, the shift registers are separate from the
cpu, i have been looking at a dead end link on NERDKITS

i can't make much heads or tails of this as of yet, but it looks like removing the cpu board and then connecting a Uno might not be that hard, but i just need some advice on connections and or if any additional parts are/would be needed. the ribbon cable lines have been identified in the link.

i am looking to understand which lines will have to be declared in a sketch, to that there is communication.

my hopes are to be able to make this into a scrolling clock / date and maybe a RSS/XML feed for weather.
thanks for any advice. please ask me anything that might help..


Need to see a schematic, or at least a block diagram, to be able to offer any help.

Or a link to the device with technical info.

Without knowing anything about the device we cannot help.


hi guys, sorry its been a while,, this project got tossed onto the back burner.. but i am trying to play with it again..

Crossroads >> this is what i have found while scouring tons of search pages on the net. usually a search shows everything but what i want.. but here is 2 links.. one is foreign, but it may contain some useful info..

if you need any more info, just ask..
i'm just looking to get some data across the screen, so that i know that a UNO or Nano can talk to it..
the old CPU unit will be removed, and uno placed in it's place..
thanks again..

In the photo, you can be pretty sure the power transistors at the lower edge are 'ROW DRIVERS', and the zillions of smaller transistors up the top are COLUMN DRIVERS.
If you check the transistor types - you'll be able to determine if the displays are driven as common cathode (high-side) or common anode (low-side sinking).

Once you have that - there are many examples online to drive the rows & columns...

Basically step through the rows - populating each LED, and turning it on for a few milliseconds, then turn off and repeat for the next row.

These displays are usually scanned vertically (it's faster - less rows than columns), but you may find some that are scanned horizontally to use less power on fewer LEDs at a given moment.
Even less common are displays that scan sideways - but break the panel into several pieces - illuminating perhaps every eighth column on each scan. (a compromise between power and refresh speed)

When you get to the last row/column - start again.
Try to keep the refresh fast enough to reduce flicker, but on_duration sufficient maintain brightness.

Scrolling effects and other tricks are not done in the display / shift-registers - but rather - in the bit-map that is shifted out each time the display is refreshed.

When you're writing code - it's useful to slow down the scanning so you can see/debug the column/row switching.

How many of you winced or smiled when he described an LED display as "old school"? :slight_smile: :slight_smile: :slight_smile:

Now, nixie tubes, that's old school.

well. the display is way over 20 yrs old..