Late April work

2026-04-26

• For loader MOVE commands and N EXT installation, detect "no EBDA present" if MEMDISK installed itself below an EBDA. This appears to be correct.
• Document MEMDISK EBDA fixes in the news-r11 section of the manual.

• Improve use with gcc-compiled FreeDOS kernel, recognise .ptext and IB sections to set gccsections variable. Also, only dump hash_section_file_offsets once.
• Support relocation type R_386_OZSEG16 used by gcc-ia16, and emitted by ia16-elf-objdump.
• Support relocation type R_386_32 for the -g output of latest gcc-ia16.
• Detect gas listing's source text lines and do not mangle them. For -g output of latest gcc-ia16.
• Skip gas listing of .debug_ sections.

• Fix large write or truncate that wants to allocate 64 Ki or more clusters. The calculation would truncate to 16 bits the amount of clusters to allocate, resulting in file corruption. (This bug is present in MS-DOS v5 as well.) The example test case in the changeset message tries to allocate more than 256 MiB on a 512 BpC, 1440 KiB image (>512 Ki clusters).
• Update lDOS version to 2026 April.
• Drop unused labels in file.nas
• Replace LocalVar macros by lframe. This is identicalised except for using lea sp, [bp - 0Ah] where the original uses sub sp, 0Ah.
• Optimise the lframe initialisation by pushing into lvar slots instead of allocating space with lea then writing the variables using mov.
• Reject extended error 5 in the 21.5A loop on dosemu2 mfs. This error is returned if the specified dirname is actually a file, eg when running 21.5A repeatedly with the same buffer. While that is a user error it shouldn't cause an infinite loop. This changeset detects whether the redirector was called, and doesn't loop on extended error 5 then (only on extended error 50h).

• Add --editor switch and N command (named for "nano" as the editor that I usually use). The N command opens the current entry's corresponding source file (found from --source directory) in an editor. IntList shells out to call the redirector.
• For small-N command instruct the editor to go to the line that's the current detail draw line start.
• Add --build switch, in small-r command run the build scriptlet to update the compiled list from the source files.
• Add I command (UR"I") to display a repo URI corresponding to an entry.
• For capital-I command use main head URI, for small-I use HEAD.
• Accept Shift-Tab as an alternative to Backtick. (Newer ConnectBot allows the programs to distinguish Shift-Tab from just Tab.)
• Add small-p and capital-P commands. Small-P saves a corresponding source file in the "preserved edit files" list while capital-P clears the list.
• Extract getsourceline function.
• Shorten message for preserved edit files.
• Set SUMMARYLINES variable for the status page.
• Show preserved edit files on the status page.
• Update the P list on a duplicate P command or if an N command is used on a file already in the P list.
• Fix matching unnamed hyperlink after a named hyperlink. The name variable needs to be reset while matching the next link.
• Clamp detail draw line start to >= 2 because line 1 is always drawn, so the first Down command should increment it to 3, not to 2.
• Reset detail draw line start upon return to list line select mode.
• Fix KEY_DOWN to display last line of entry. Apparently an off-by-one error. (Related to clamping detail draw line start?)
• Adjust the cursor set column by stop position.
• Use a global stop variable throughout.
• Keep track of hyperlink visibility.
• Add a capital-L command with some options.
• Change capital-L command interface.
  • + and - change the index but don't load a hyperlink.
  • = allows to enter an index on a command line, but doesn't load a hyperlink.
  • Enter loads the selected hyperlink.
  • L acts like + then Enter initially, or like only Enter as a subsequent command.
  • Q returns to the main interface.
• Extract functions getpriorstate and setnewstate.
• Set the unique ID and summary base variables on a successful selecthyperlink run.
• Change capital-P command to a new interface, in which D deletes and L is a no-op as yet.
• Extract function enterresultfile.
• Implement capital-P L command (load all entries referenced by a hyperlink, and add corresponding source files to the preserved edit files list).
• Add capital-P commands:
  • N to edit the preserved edit files list, but without editing the current entry's file.
  • M to edit only the current entry's file (ignoring the preserved edit files list) without clearing the list.
  • E to set the editor command to use.
• Reset to the topmost mode on E command ("end file", ie close a list file).
• Reverse order of files added using capital-P L command, so the first hyperlink match is edited first.

The capital-P L command is fairly slow. It may be better to collect the hyperlinked entries' unique IDs and summary base lines then search for all of them using a single Path::Iterator::Rule run.

• ecm 2026-04z: CMOS typos, update termination functions 21.4C and 2F.111D, detail on 2F.1121 being called only when EOF can have changed, add dosemu2 redirector extensions 2F.1142, .11A3, .11A6, .11C2
• ecm 2026-04aa: Move an 21.40 line from BUGS to Notes, update 21.31, .3F, .40 (FreeDOS and MS-DOS v5 bugs), .50 and .51 (FD/Enhanced/lDebug use direct SDA access, emu2 bug), .56 (shell limitation and wording mistake), .58 (first UMCB position), .59 (error 0Bh and 11h functions), .5D0B (disk full byte is marked with a ">32mb" comment, which means it was added for the MS-DOS v3.40 development branch rather than stating that it only applies to large partitions).
• ecm 2026-04ab: Fix a spelling mistake in glossary entry for IBM, list more functions that may generate errors in 21.59, 21.5A updates and hyperlinking between it and 2F.1118, add sort-as IDs to 21.4402, .4403, .4404, .4405, add sort-as IDs to COMTROL interrupts, update INT 22, add INT 21 entry for DOS functions generally.