Scott Baker managed to buy a Ciarcia Trump card on eBay in 2022, without disks of software (someone sent him those later). 

The board does have two 2K boot ROM chips, which only have about 62 bytes of active code. And they are listed in the articles. I have OCR'd them and posted them here.

The code talks through a 2K RAM with the address lines driven by a counter. The interface is the 8-bit PC bus, which is completely obsolete in 2023.

Since the boot code is simply to load code through an 8-bit stream, a modern alternative might be to use an FTDI 8-bit FIFO USB module. You could then hurl a block of code through a virtual terminal then run it.