A summary of the above would be "...use abank of physical switches to directly input binary data to memory " while the computer is halted. Back in the "old day

A summary of the above would be "...use abank of physical switches to directly input binary data to memory " while the computer is halted. Back in the "old days" the 80's ... we would get a static RAM chip (6116) put a battery on top of the chip along with a bit of circuitry to make "battery backed" could use the physical switch method to load a program into such a setup and then plug this RAM into computer, would need to be a right location in memory map for it to work... From Google - describes such a circuit / mod from Elektor magazine ... "An Elektor article from June 1985 describes a plugin circuit for using two battery-backed 6116 RAM chips as a replacement for a 2732 EPROM. This circuit uses a 2-bit binary decoder to select the correct 6116 RAM chip, ensuring proper operation and data retention via a battery backup, a key feature of the low-power "LA" version of the 6116 chip. ..."