CTR-201 manual by GTEL
Programming the Protel CTR-201 COCOT by El Oscuro unofficial guide, has more details on rate bands

310 manual by GTEL

Protel 7000 manual - complete manual by Protel. Installation, initialization, troubleshooting, specs.

Protel 8000 manual - complete manual by Protel. Installation, initialization, troubleshooting, specs.

Ascension User's Guide
Elite User's Guide (has more details than Ascension's)
Charge-A-Port User's Guide - details on how the modem port worked

expressnet_manual.pdf - complete Expressnet manual, 1995

Programming Protel 7000: test of various consumer-grade modems - Using a standard modem with Protel 7000
Programming Protel payphones A quick manual by El Jefe on using ExpressNet to program a Protel board
Programming call routes using Protel Another great manual by El Jefe on using ExpressNet to program call routes
How to initialize Protel phone One-page instruction on how to initialize the payphone
Protel manual programming One-page summary on how to program rates using keypad, not a complete manual but useful

ExpressNet III ver. 1.44 - the most important piece of software, MS-DOS needed.
ExpressNet III ver. 1.55 upgrade - newer version. 1.44 needs to be installed first.
Sample rate and options - rate file for 724-745-XXXX. Outdated (1998) and not really needed.
ExpressNet III ver. 1.30 - floppy disk image, release by PhilTel & danc256
ExpressNet III ver. 1.40 - floppy disk image, release by PhilTel & danc256
Virtual Box image - Virtual Box image (ExpressNet 1.55 + 602 rate file + all firmware files available, release by telesfor.org). Manual included.

There are two types of firmware files: DD upgrade files - to be remotely uploaded by ExpressNet software, to either Flash or non-flash phones, and EPROM chip dumps (you can program it outside the payphone and physically replace). The latter ones contain not only a firmware (first 128kB block), but also voice prompts (the second block). Those are common for most of main board types.
Q.: can they be converted from one type to another?
A.: probably, but not right now. DD files have more complex structure with redundant data. Maybe some day I will find out the way to convert them, if it's even needed…

Do you need any EPROM programmed? Please let us know.

DD upgrade files: (copy to c:\xnet\param\software, see instructions inside)
DD firmware files - early upgrade files (-231) - 12.1997 for 2000/4000/7000/8000. Deprecated.
DD firmware new - large (31) collection of upgrade files, available thanks to PhilTel & danc256. Some as new as 2004, never published before.

EPROM dumps: we currently have a very limited number of firmware files we extracted from the boards. You can also find UPMS1200 modem firmware dumps below thanks to PhilTel & danc256

• Protel_4000_8000-M27C2001-DD8822-00-000.BIN256 kB
• Protel_7000-M27C2001-DD7018-00-800.BIN256 kB
• Protel_7000-M27C2001-DD7019-00-231.BIN256 kB
• Protel_7000-MC272001-DD7018-00-356.BIN256 kB
• Protel_CTR200.zip107.59 kB
• protel-upms1200-3.7.BIN32 kB
• protel-upms1200-4.1.BIN32 kB

List (not complete) of firmware revisions with release dates. We have no further details of what was improved.

*1) Updated version of Firmware DD Release DD-XX21XX-XXX. The new #2 bulletin contains a revised chart outlining the operation of the Call Restrict, CDR and Capture Digits features. Mars Electronics® MS-16 coin mechanism is not compatible with DD7021 firmware.
*2) ECS II may become disabled after downloading DD-XXXX-XX-231 firmware.