Non-standard use of POS terminals, is it possible to launch the kernel?

Question

linux

Good day dear!
I inherited 5 pieces of POS payment terminals (from a private bank)
Model: Ingenico ICT220
Stuffed with a bunch of all sorts of interfaces.
There is nowhere to use them for their intended purpose, and there is no point, perhaps someone knows how to "communicate" with them, there is not a lot of information on this issue on the Internet.
It would be possible to use their capabilities to good use
- to make a mini-mining of coins,
- to print all sorts of notifications on a thermal printer
- to control something remotely (something like a smart home)
, in fact, it's all sorted with minced meat!
In general, the essence of the question is probably clear, does anyone have information?
Some specs:

Country of manufacture Russia
Processor ARM9+ARM7 (450 MIPS+50 MIPS)
Memory 16 MB
RAM 16 MB
Keyboard 19 keys
Magnetic card reader 1, 2 and 3 lanes
Number of USB ports 2
Network (LAN) Dial-up Modem, Ethernet, GPRS
Resolution display 128x64
Liquid crystal display
Print speed 60 mm/s
Consumables Thermal tape 57 mm
Interface RS-232, USB
Power supply Mains supply

Answer 1

Hang up , found info on the forum: bankomatchik.ru/forums/34?start=50
Terminals are very well protected, Kuota "The first problem is that Ingenico terminals are activated upon delivery for a specific dealer who writes the software.
Therefore, before uploading, it is necessary compiled files must be signed with the digital signature of this dealer, otherwise the terminal will simply not accept them." bankomatchik.ru/forums/34/5219

Answer 2

They can not even be opened, when opened, the sensor is triggered and the keys are erased from memory.