Background

A herd of ATMs roaming into their temporary habitat
Data Flow for Processing

Getting Started

(Localized) External Payment Processor device (ATM Dialup to Ethernet)
Getting data byte by byte and the true and proven asdfasdfasjlfdasdfasdfadsfsdf for responsiveness testing
Visualization of the data coming from the serial data of the modem

Decoding and Processing

ATM Processing Request: Send ENQ -> ATM Responds -> You Respond -> You ACK -> You send EOT -> Disconnect
ATM Processing Request: Send ENQ -> ATM Responds -> You Respond -> You ACK -> You send EOT -> Disconnect
Flow Diagram for ATM Communication over Dial-Up
Screen capture from the Protocol Guide indicating supported protocols and reset options
The hidden piece we needed to make the ATM respond, from 1994
jrwr peering into the newly “operational” ATM with the out of service error

Making Bank

Serial Processor Logic
PBX and USB Serial Modems
The “0x0A” issue…
Reason -00010.00 I should not be a payment processor

Wrapping Up

Future Work

CPTC dog mascot tax!

Just some spicy avocado