https://pushbx.org/ecm/dokuwiki/ 2026-04-17T12:55:39+00:00 https://pushbx.org/ecm/dokuwiki/ https://pushbx.org/ecm/dokuwiki/lib/tpl/dokuwiki/images/favicon.ico text/html 2026-01-12T20:21:05+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0112_early_2026_work_on_emu2_etc_test_cases?rev=1768245665&do=diff Early 2026 work on emu2 etc, test cases 2026-01-11 lDOS kernel * Implement COMPAT option NOCOLLECTALLMCBS. Using this makes it so the lDOS allocate memory functions won't collect all free MCBs before running the main loop to allocate. Instead, every free MCB encountered during the main loop collects free MCBs after itself. This is text/html 2026-01-13T20:23:56+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0113_some_more_test_cases_as_of_recently?rev=1768332236&do=diff Some more test cases as of recently Trace Interrupt + Other Interrupts tests My first attempt test.asm: Hook interrupt 8 (IRQ #0) and interrupt 1 (Trace) and try to check when the IRQ is delivered, if the Trace Flag and Interrupt Flag are set by the same text/html 2026-01-16T15:38:42+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0116_idiom_on_having_written?rev=1768574322&do=diff Idiom on having written I'd rather outsource watching sunsets idioms text/html 2026-01-19T19:44:35+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0119_early_mid_january_work_on_the_mcp?rev=1768848275&do=diff Early mid January work on the MCP 2026-01-18 This week I put some work into the Master Control Program (MCP), and a new helper utility called the Codified Likeness Utility (CLU). (Both, of course, named for programs in the Tron franchise.) The MCP is stored in a file named ldosmcp.com or ldosmcpz.com which contains the lDOS kernel, a triple-mode lDebug build, the lDOS pre-boot loader, the instsect tool to install boot sector loaders, the patldos tool to patch lDOS kernel files, an Extension fo… text/html 2026-01-19T19:34:29+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0119_mcp_boot_menu_timer_test_cases?rev=1768847669&do=diff MCP boot menu timer test cases Two test cases that I created to debug the timer for the Master Control Program's boot menu default. I submitted these to a dosemu2 repo discussion. First attempt 20260114/test.asm: This is the first attempt, cut directly from the MCP development repo. (Because it uses some macros, particularly the text/html 2026-01-20T17:23:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0120_debugger_command_to_dump_the_first_system_file_table_entries?rev=1768926202&do=diff Debugger command to dump the first System File Table entries I added to the ~/.dosemu/drive_c/ldebug.sld file so it contains the following: @:applicationstartup @:devicestartup @install getinput @install quietinstall @ext extlib.eld quit.eld install @ext extlib.eld extname.eld install @extname lib set c:\extlib.eld @install quickrun @ext alias install @ext rcexec install @alias add sfd rc.execute @dw ri31s:CC + 6 + 0 * 3B l 3B; @dw ri31s:CC + 6 + 1 * 3B l 3B; @dw ri31s:CC + 6 + 2 * 3B l 3B; … text/html 2026-01-23T19:54:10+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0123_idiom_on_mistakes?rev=1769194450&do=diff Idiom on mistakes The Daily WTF article idioms mistakes smart wise text/html 2026-01-25T16:28:11+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0125_late_mid_january_work?rev=1769354891&do=diff Late mid January work 2026-01-25 This week a little work happened. The MCP and CLU also got alternative backronyms to describe what they do: Multiple Command Payload and Comspec Load Utility. MCP/CLU * Try to enlarge CLU's environment if insertion of the COMSPEC variable fails. Due to a hack, this is likely only needed when the CLUMCPFLAG indicates that CLU shouldn't relocate its process. (The hack is that if the process is relocated, text/html 2026-02-01T17:49:37+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0201_overview_of_educational_topics?rev=1769964577&do=diff Overview of educational topics This article lists some topics I think any education on program logic work should cover. I collected these notes over several months, though I have thought about many of these for years at this point. Debugging Debugging is a crucial skill for working with software. Whether it be tracing, inserting log or print statements, or "rubberduck debugging" (explaining the logic of the program to someone else or to an object). text/html 2026-02-02T20:08:10+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0202_late_january_work_on_traclist?rev=1770059290&do=diff Late January work on TracList 2026-02-01 The idea of these changes is to take an existing trace listing (.tls) file of the lDOS kernel and find corresponding offsets within the MS-DOS v7.10 kernel. As they're both based on the same code base, I expect that there will be some similarities remaining. text/html 2026-02-04T18:40:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0204_chasing_a_warplink_bug?rev=1770226800&do=diff Chasing a WarpLink bug Today I used the current WarpLink revision, "release 4 by ecm (2025 September)", trying to peruse some details in preparation for a new feature. Cue my surprise when it failed to link even the simplest examples! The error Observe: text/html 2026-02-10T16:36:09+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0210_early_february_work_on_warplink?rev=1770737769&do=diff Early February work on WarpLink 2026-02-08 This week I worked on WarpLink some and a bit on the lDOS kernel. The lDOS changes are to make use of a new feature, the WLCALC post-link calculation. WarpLink * Fix a bug where files without fixups would fail to initialise data_fixup_count. This is described in some detail text/html 2026-02-15T21:44:37+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0215_early_mid_february_extensions_to_warplink?rev=1771188277&do=diff Early mid February extensions to WarpLink This is not actually a regulation Sunday blog post as I didn't prepare it on the HP 95LX, due to the place I usually write these being closed for the carnival days. This week I prepared some new extensions to the WarpLink OMF linker, most of which was originally written in 1989 through 1993, and released to the public domain in 1999. I have been working on WarpLink since 2023. text/html 2026-02-16T14:03:36+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0216_recent_warplink_tests?rev=1771247016&do=diff Recent WarpLink tests These tests were written to test several of the wlcalc and wllist features during their development. They're all stored in <https://pushbx.org/ecm/test/20260204/> The scriptlets The basic assemble and link scriptlet looks like this (as of the most recent WarpLink revision - some of the switches require a newer revision than others). It assembles the test object file, then links it using the local text/html 2026-02-25T16:53:47+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0225_late_mid_february_work_on_warplink?rev=1772034827&do=diff Late mid February work on WarpLink 2026-02-22 lDebug A new lDebug release, r10, has been uploaded. As part of the release three changesets were created: * LSM update and indicating the r10 release date in the manual's News chapter. * Branch named for release10. * Uncomment the r11 future news section in the manual. Also, the release is now listed as a news item on the ecm webpage. WarpLink text/html 2026-02-27T17:11:42+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0227_alignment_calculation_in_three_instructions?rev=1772208702&do=diff Alignment calculation in three instructions Found in a 2025-08-29 changeset of the ecm fork of WarpLink: mov bx, [alignment_table + bx] ; bx = alignment mask and ax, bx neg ax and ax, bx and neg and. That's odd. I assume it works because I would have worked it out at the time but it's not intuitive. text/html 2026-03-04T17:14:00+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0304_late_february_early_march_work_on_warplink?rev=1772640840&do=diff Late February (+ early March) work on WarpLink 2026-03-01 WarpLink * Bugfix, read back the tempwllist structure after the innermost loop may have run, to update it with twlListUsed set to twlUsedListItem. * Fix to preserve the ?collectfunction across the call to the innermost loop. This bug took me more than 60 minutes to properly diagnose. * Fix repeated wllist entry crossing the boundary of a LEDATA block. The prior code assumed that the LEDATA boundary would always coincide with a te… text/html 2026-03-09T18:43:41+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0309_early_march_work_on_ldebug_warplink_ident86_and_patchini?rev=1773078221&do=diff Early March work on lDebug, WarpLink, ident86, and patchini 2026-03-08 This week I uploaded a new branch to the lDebug repo, updating the sources to build with a makefile that assembles multiple object files, then links them using the WarpLink linker. text/html 2026-03-15T17:40:05+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0315_early_mid_march_work_on_several_bits_and_bobs?rev=1773592805&do=diff Early mid March work on several bits and bobs 2026-03-15 patchini * Extract lib.asm from patldos assembly language port * Move the cut function into lib.asm * Extract msg.asm from patldos * Re-use lib.asm in patchqry.asm * Add option define _INCLUDEPATCHQRY for patldos.asm * Extract messages from patchqry.asm into msg.asm * Add sections to assembly language sources (CODE, DATA, and BSS) * Enable assembling both tools together * Call patchqry as a subfunction from patldos.asm… text/html 2026-03-22T17:57:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0322_late_mid_march_work_on_ldebug_c?rev=1774198678&do=diff Late mid March work on lDebug &c 2026-03-22 WarpLink Emit a THEADR (Translator Header Record) to the wllist object file, to conform to the specs and not use a stale filename in the Module column of the .map file segpart list. Reference to the OMF guide is in the changeset message. tractest text/html 2026-03-28T13:25:24+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0328_comments_on_label_delta_arithmetic?rev=1774700724&do=diff Comments on label delta arithmetic Today I posted a stackoverflow question and answer on how to do arbitrary calculations on assembly language labels, How can I do arbitrary calculations on assembly language labels?. As a companion to that question, here is a collection of comments in which I have referred to label delta arithmetic before. text/html 2026-03-28T10:27:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0328_lz-style_match_copy_in_a_window-sized_circular_buffer?rev=1774690042&do=diff LZ-style match copy in a window-sized circular buffer I consider this code "a small masterpiece of 8086 assembler programming", unlike LZEXE's online depacker which buffers the entire depacked data. This code enables streaming decompression with a buffer exactly the size of the match window, for arbitrarily large streams of data. text/html 2026-03-30T09:28:43+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0330_what_is_a_debugger_and_how_can_it_help_me_diagnose_problems?rev=1774855723&do=diff What is a debugger and how can it help me diagnose problems? 2014-08-19 answerRaedwald linkspam text/html 2026-04-03T19:09:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0403_late_march_work_on_the_debugger_and_kernel?rev=1775236198&do=diff Late March work on the debugger and kernel 2026-03-29 This week I also finished my stackoverflow.com Q&A and companion blog post on NASM label delta arithmetic. I have espoused the use of this for years, but there wasn't a canonical explanation to refer to yet. BTTR Software bootmgr After seeing it listed text/html 2026-04-12T16:07:50+00:00 Anonymous (anonymous@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0412_early_april_work_on_intlist_ldos_boot_ldebug?rev=1776002870&do=diff Early April work on IntList, lDOS boot, lDebug 2026-04-12 This week I got IntList into a state where it does most things I want it to do. tractest/intlist.pl * Highlight potential links. * Highlight references to tables too. * Allow marking the first link using Tab. * Allow to tab through visible links. * Cycle back to first visible link after the last one. * Re-calculate firstlinkline every time the pane is redrawn.