OK I did a search for a configuration of a late 2012 Retina Mac Book Pro….this gives me a fighting chance to see what it takes to repeat this. Thanks for your help!
MacBook Pro (Retina, 13-inch, Late 2012) - Technical Specifications
Display
Retina display: 13.3-inch (diagonal) LED-backlit display with IPS technology
2560-by-1600 native resolution at 227 pixels per inch with support for millions of colors
Scaled resolutions: 1680 by 1050, 1440 by 900, and 1024 by 640 pixels
Processor
2.5GHz
2.5GHz dual-core Intel Core i5 processor (Turbo Boost up to 3.1GHz) with 3MB shared L3 cache
Configurable to 2.9GHz dual-core Intel Core i7 (Turbo Boost up to 3.6GHz) with 4MB shared L3 cache.
Memory
8GB of 1600MHz DDR3L onboard memory
Storage
128GB
Configurable to 256GB, 512GB, or 768GB flash storage.
256GB
Configurable to 512GB or 768GB flash storage.
Size and Weight
Height: 0.75 inch (1.9 cm)
Width: 12.35 inches (31.4 cm)
Depth: 8.62 inches (21.9 cm)
Weight: 3.57 pounds (1.62 kg)2
Graphics and Video Support
Intel HD Graphics 4000
Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 2560 by 1600 pixels on up to two external displays, at millions of colors
Thunderbolt digital video output
Native Mini DisplayPort output
DVI output using Mini DisplayPort to DVI Adapter (sold separately)
VGA output using Mini DisplayPort to VGA Adapter (sold separately)
Dual-link DVI output using Mini DisplayPort to Dual-Link DVI Adapter (sold separately)
Camera
720p FaceTime HD camera