Motorola 22F43 14pin dip identify me

[CapLeaker]

Got an old Motorola page out controller here. Something honking old. Came in as no workie. Without schematic or anything. So I did some probing around and found two 14 pin DIP IC's that I need an replacement for.
Motorola 22F43
Motorola 22F44
Got no idea what these are.I got semi lucky and found a 22F44 on a donor. Unfortunately the 22F43 is already missing. If anybody knows what these are and find a cross would be greatly appreciated!

[CapLeaker]

[truclacicr]

Maybe try here?

https://mirrorservice.org/sites/www....ents/motorola/

The sequential part numbers suggest that these ICs may be a functional pair, perhaps a transmitter and receiver?

[redwire]

I found pretty much nothing, it's house numbered

Motorola Telecommunications Device Data DL136 archive.org would likely have the (telecom) IC's but almost all have "MC" prefix. The older databook has app notes which can help if you know the building block functions. With no MCU, I expect a lot of vanilla CMOS logic though.
Is this using DTMF or a codec, modem? All it has for UI is a 7-seg LED display? The IC's connect to a keypad?

Only tidbits I found:
87K01 - SC45070PK/45070 - MC14049UBE
87K09 - MC14028BCP

[CapLeaker]

redwire
This thing is a Pager for a Fire Department and is hooked up to a VHF radio. It has a single digit display and yes there is weird number pad hooked up to it. It must be somewhat programmable. You press the number 1 on the keypad, which sends out a DTMF two tone to open the squelch on the pager. Then you relay a one way message.
I also had a look at an old Motorola book and didn't find anything a 22F43 or an 22F44. There must have been some real old Motorola books with cross references at some point.
Those chips must have been available at some point, because one of them was socketed already. The donor had the socket and the IC missing.
The number pad hooks up right to the pin strip top left underneath the transformer, below that resistor bank.
Once powered up, this thing supposed to show a “0” and then turn to a “1”. First ist always stayed a “0” until I swapped the 22F44. Now it shows a “9” and the relay is continuously on. I swapped the IC to the right of 22F44 as it had a 50% chance of being bad, but turns out the 22F43 is bad, but I don't have a replacement, nor have a clue what it is.
Thanks redwire, even for the little Timbits! This thing should be in a museum, not on my bench for repair. Lol

[CapLeaker]

Maybe try here?

https://mirrorservice.org/sites/www....ents/motorola/

The sequential part numbers suggest that these ICs may be a functional pair, perhaps a transmitter and receiver?

It’s CMOS. I can tell you this much. If I pull 22f43 or the 22f44 it will hinder the unit and just displays “0” these two are not directly connected to each other and they have a few pins each going to the keypad. Also the 22f44 has something to do with the relay.

[redwire]

Ah the pic has more keywords "Motorola Alert Central Paging Encoder"

I did see the 1976 service manual eBay USA https://www.ebay.com/itm/33521188797...item4e0c2f7d64 1 day left, maybe email the seller.
Aaauuurgh fuzzy pics https://www.worthpoint.com/worthoped...ert-4584348476

unit for sale on eBay Canada https://www.ebay.ca/itm/115744377976...item1af2e70c78


"The Moden/100, Moden/36 and Alert Central paging encoders are pretty much the same thing with little difference in features. They all are covered by the same service manual. It is only capable of 6 tones in the PROM.
The tones encoded are are controlled by ROM's U22, and U28. These are Harris Semiconductor HM1-0186 Commercial Diode Matrix. These are a 6x8 diode matrix, which adds up to 48 diodes on the inside.
The links of the diodes inside represent the tones. There are tables in the manual that show how the bits should be.
It's in a 14 pin package. These had to be pre-ordered in bulk from Harris."

[truclacicr]

If the chips are decoding the keypad, then perhaps one is driving the rows, and the other the columns. I would trace the circuit in that area, then we could see what common chips might fit the application.

[CapLeaker]

interesting find redwire. Damn... I wish I could find my glasses this morning... LOL I put em somewhere yesterday...

[redwire]

Just don't sit on them lol. I need new ones but got used to the blur.
This pager thing is a ~1976 design with 1980's build. A long run. It's hard to know how this works - no MCU means it's a simple state-machine I guess.

I wonder if the keypad IC's get zapped with static. Strange they are another numbering scheme different from the other IC's. The Motorola keypad IC's of the era are scan/decode to tone. Like MC14419 does keyboard scan to BCD, MC14410 tone encoder.

[CapLeaker]

Left my glasses on my workbench at work. At least I didn’t sit on it. lol. It’s not the keyboard that gets zapped. On most of them the little transformer has an open primary and they just put a DC wall wart on it. That 22f43 also has something to do with the relay. No MCU on this old thing. I don’t understand the old numbering scheme from Motorola at all. Never seen the letter F in between numbers.

[sam_sam_sam]

I got to ask the question what do you plan on doing with this device if you manage to get it working again

[CapLeaker]

Goes back in service to a certain FD.