I recently impulse bought an ElectroCom Communication Systems MDT-870 radio car terminal for $5 at a surplus sale. Never knew much about these sort of computers but learned a lot since, and yet remain largely in the dark about this particular model given the complete absence of any documentation or schematics online.
This model in particular was common in squad cars in the 1980s-1990s. Some metadata extracted from a ROM that I dumped when troubleshooting indicated "COPYRIGHT 1986-1996 ELECTROCOM AUTOMATION INC." and the particular ROM in this unit had a generation date of March 25, 1996. Based on this, the department may well have used it for the better part of a decade before phasing it out in favor of more contemporary solutions.