I like your ideas, Brian, and how wide-ranging you've made your program. Does it also handle James Yi's HXFER format?
My [co2do](https://github.com/hackerb9/co2do/) is definitely more of a one-trick pony. Still, it's not a bad trick. I've managed to get the VARPTR working on the NEC, so now it generates a single .DO file which should work on any Model T and loads quickly using M/L in a string. You can try it out with my [universal ROM checksum program]( https://raw.githubusercontent.com/hackerb9/co2do/refs/heads/main/testfiles/CRC16.DO) that also should work on any Model T. (Well, except I haven't trimmed the fat yet and it doesn't fit on an 8K machine anymore.) ____ By the way, can anyone with a y2k-patched 8201A and/or 8300 confirm the checksum for those ROMs? Mysteriously, the NEC ROMs that ship with Virtual T are not the same as the ones available on http://tandy.wiki/Model_T_System_ROMs and I'd like to know if those were made specially for Virtual T or what. (And actually, I'd welcome any reports from anybody who has a machine and tries out the checksum program, even if it identifies it correctly, as nearly everything in my [ROM table]( https://github.com/hackerb9/crc16-modelt/blob/main/table.md) right now is unverified.) ____ Next steps for co2do: Shrink the loader down so it can fit larger .CO files on 8K machines. Warn the user if the resulting file won't work on machines with limited RAM (higher MINRAM) or have lower MAXRAM (Tandy 200). Automatically adjust the string space and maxfiles if the RAM limit is close. Automatically use smaller, slower code if the RAM limit would be exceeded. Consider using SAVEM automatically if `fre(0)` says there's enough space, otherwise create a trigger file. Make it easier to have multiple payloads in a single file. Maybe read directly from the serial port for even more speed. Double-check that co2do runs under Mac OS and WSL for Microsoft Windows. —b9
