Thank you to Steven, Brian, Kurt et al. for your suggestions. This is the TPDD, catalog 26-3808.
I think the simplest option for me is to order one of the TPDD disks from Arcade Shopper, which I will do today. The manual describes the boot process from the disk. I do have a cassette drive, CCR-81, but I don't have REX implemented yet and would like to verify operation sooner rather than later. I'll report back when operational. Thanks again for your responses. -CH- <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
