I remember variants on this for several platforms by the authors: Don Inman, Ramon Zamora, Bob Albrecht. TRS-80: https://www.amazon.com/Advanced-TRS-80-Level-

I remember variants on this for several platforms by the authors: Don Inman, Ramon Zamora, Bob Albrecht. TRS-80: https://www.amazon.com/Advanced-TRS-80-Level-II-BASIC/dp/0471096776 https://www.amazon.com/Advanced-TRS-80-Level-II-BASIC/dp/047... TI-99/4a: https://www.amazon.com/Introduction-TI-BASIC-TI-99-4A/dp/0810451859 https://www.amazon.com/Introduction-TI-BASIC-TI-99-4A/dp/081... Visual basic for dos: https://www.amazon.com/Visual-MS-DOS-Prentice-Innovative-Technology/dp/0139486623 https://www.amazon.com/Visual-MS-DOS-Prentice-Innovative-Tec... VIC-20: https://www.amazon.com/Vic-BASIC-User-Friendly-Guide/dp/0835983773 https://www.amazon.com/Vic-BASIC-User-Friendly-Guide/dp/0835... Here is the full TRS-80 text: https://archive.org/details/trs-80-level-ii-basic-a-self-teaching-guide https://archive.org/details/trs-80-level-ii-basic-a-self-tea... Who were these guys? They were all over the map.