[cctalk] Re: DLOAD BASIC command for Color Computer 1/2 heritage

Just some references: https://techheap.packetizer.com/computers/coco/unravelled_series/color-basi… This states DLOAD is input only On page 88, I don't see DLOAD listed - it goes from CLOADM straight to EXEC (so it is not clear to me on how DLOAD is implemented) https://colorcomputerarchive.com/repo/Documents/Books/Unravelled%20Series/e… "DLOAD is the most obscure command in the Color Computer and absorbs a substantial amount of space in the ROM. DLOAD is so poorly understood because Tandy has never made the necessary companion routine, DSEND. DLOAD will DOWNLOAD a file over the RS 232 line from another system, however there is no companion routine, which will transmit a file over the RS 232 line to another Color Computer. Once a DSEND routine is built and made available to the masses, DLOAD will be much better understood." In the Extended BASIC ROM, it does have a section for DLOAD (and I think a DLOADM?). Maybe inspecting that code might give some idea on its origin. Maybe DLOAD was a way to stream in a newer test ROM or other system test/support software from a "larger" machine {e.g. a mainframe with a 6809E emulator?}). http://vtda.org/docs/computing/RadioShack-Tandy/8759038-780-SL_TRS-80ModelI… I don't see DLOAD listed for the TRS-80 Model 3 (there is an INP keyword that talks about PORT 0-255, and this manual talks about supporting two cassette ports) https://ia801906.us.archive.org/30/items/Introduction_to_TRS-80_Level_II_BA… No DLOAD in the TRS-80 Level 2 BASIC (I spot checked to see if it might be under a different name, nothing stood out) https://archive.org/details/IBMBASICAV1.10Manual/page/n13/mode/2up No DLOAD in the IBM 5150 BASIC 1.10 (some suspects: LOG, LOF, GET/PUT, COMn statement, IN/OUT - maybe one this means DLOADM?). Appendix F-2 describes using BASIC to interface with the Async Serial IO Adapter, page F-8 describes using the INP keyword) Not sure if any that helps on the lineage of DLOAD. I looked at the Altair BASIC manual, didn't see any DLOAD there. And also the IBM 5110, (NOT a Microsoft BASIC) http://www.bitsavers.org/pdf/ibm/5110/SA21-9308-0_IBM_5110_BASIC_Reference_… Not sure if any of that helps, in terms of finding the DLOAD protocol. In the Color BASIC unravelled (first link), some of the code talked about using SPACE? As-in, something different than 8-N-1 (the SerialIO could also be used for a printer, so maybe 7-SPACE-1?). -SL On Mon, Jan 30, 2023 at 12:02 AM Jim Brain via cctalk <cctalk(a)classiccmp.org> wrote: