Elcotel
Ernest 7D model released in 1987[citation needed]. Likely not NANP-compatible. Not programmable remotely. Many 7D phones were sold by Amway, sometimes considered a scam, and some of those phones can still be purchased brand new on ebay.
The most known phone was the ETX model (and similar: 7-D3 - most likely the difference was mainly the firmware, D3 using D32 series and ETX - D40[citation needed], EG series - same firmware as D3, minor differences in electronic design). ETX was programmed remotely via a modem, software for Windows 95/98/NT is available. Programming the rates is difficult or impossible, but rate override is enough to make it usable. Keypad connector is DB15, different than Protel or Elcotel. Allegedly there were different revisions designed for Elcotel/GTE or AT&T keypad as well. Pictured below: Ernest EG, around 1999:
Main chips: CMD G65SC151 (CMOS 6502 derivative), μPD7759 ADPCM voice generator, MT8870 DTMF decoder, TDK 73K212 (1200 bps modem), X28HC256SI (32kB EEPROM), D43256B (32kB static RAM), M27C256 (32kB program ROM) and AT27C010 (128kB voice ROM).
Startup:
D3 / EG/ ETX does not need the external power except a good 3V lithium battery. In some models it is a common CR2032, in some - soldered battery. It is needed for startup. Initial use may take some time before you hear the dial tone (maybe 30 seconds) to charge internal capacitor. No external power is needed however in some cases it improves the overall experience. DC adapter voltage is not documented but the charging voltage is 12V - therefore I think it's safe to start with 9V adapter, or adjust it to 12V, but not higher.
Programming:
Programming can be done using the Telelink software (Windows 95/98/NT4.0 - can be emulated), a modem, and two phone lines (one for a modem, one for the payphone). As of now, rate files are not available and impossible to edit. However rate override is possible (separately for 7, 10 and 11-digit numbers) using “programmable features” settings. Alternatively (and actually easier in most cases) the options (including rate override) can be programmed locally, but the LCD display needs to be attached (we're planning to start selling one on Ebay in Sep. 2026 for $25 shipped).
Remote programming with Telelink is a bit different than Protel and Elcotel. It lets you save all the current settings. Different type of data (options, rate table, speed dials) are transferred independently. There's one catch: you need to know the 6-digit ID number to connect to the phone. Sometimes it's 000000 but sometimes it's programmed differently and the only way to change it is local programming. If you don't have the LCD display, here's the sequence: shift the program switch to the right, go off hook. Press: * 0 1 [wait 3 seconds] 000000 *. Hang up and shift the switch left. This should zero the ID.
Related documents:
ETX payphone manual
Telelink quick start manual
Photos of inside + how to override the rates
How to connect a regular 16x2 LCD display
Telelink 2.61 - Windows 95/98/NT4.0 software to program the payphone, includes manuals
Ernest 7D Operations Manual 1987 (archive.org)
Ernest D3/ETX voice prompts