https://pushbx.org/ecm/dokuwiki/ 2026-06-02T19:34:38+00:00 https://pushbx.org/ecm/dokuwiki/ https://pushbx.org/ecm/dokuwiki/lib/tpl/dokuwiki/images/favicon.ico text/html 2026-06-02T16:44:37+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0602_mid_to_late_may_work?rev=1780411477&do=diff Mid to late May work 2026-05-31 lDOS kernel * Fix to not find a character device on FindFirst with an exact name match and the volume label attribute bit set. (Contains testfind.asm, a test case.) This bug used to be documented in the interrupt list, except the sense is wrong. The intended (MS-DOS v5) behaviour is to never find devices when searching for labels. The DEVNAME function checks "Attrib" to determine that a label search is in progress, but it was set from "SAttrib" only later. Th… text/html 2026-06-01T20:03:02+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2025/0119_ms-dos_simpler_buffers_and_doscode_split?rev=1780336982&do=diff MS-DOS: simpler buffers and DOSCODE split 2025-01-19 This week I first uploaded some changes from the last 20 days concerning an adaptation of the MS-DOS v2.11 buffers subsystem to the lMS-DOS code base. Then I worked on splitting the DOSCODE segment from DOSDATA. This work isn't finished: While the split is done, it is not yet useful. But the hardest part seems to be done. text/html 2026-05-28T21:15:17+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0528_two_hard_problems?rev=1779995717&do=diff Two hard problems Leon Bambrickquoted by Martin Fowler That page collects some more variations on this idiom. idioms text/html 2026-05-18T19:55:11+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0518_early_mid_may_work?rev=1779126911&do=diff Early mid May work 2026-05-17 This week I worked some on debugging DR-DOS v9. The relevant updates to the debugger and loader are listed in yesterday's blog post dedicated to that. Except for Sunday's update to the manual to list nreserve.eld more completely. The only other changes concern the list and WarpLink. text/html 2026-05-16T20:40:11+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0516_dr-dos_v9_trial?rev=1778956811&do=diff DR-DOS v9 trial I tried out the most recent build of DR-DOS v9 recently. In case you're unaware, DR-DOS v9 is a new project that provides a proprietary and closed source DOS that is "a faithful clean-room reimplementation" coupled with the original trademark for DR-DOS. It is "free to download and use for personal, educational, and hobbyist purposes", but does not appear to permit redistribution. text/html 2026-05-11T16:49:53+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0511_early_may_work?rev=1778510993&do=diff Early May work 2026-05-10 IntList For the capital-P L command (add all matching hyperlinked entries to preserved edit files list), resume the hyperlink search at the prior match rather than starting anew. This reduces the time for capital-P L "21.4402" (which adds 32 entries) from more than 4s to about 1.7s. text/html 2026-05-08T16:58:21+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0508_when_0_paragraphs_free_is_not_the_same_as_0_paragraphs_free?rev=1778252301&do=diff When 0 paragraphs free is not the same as 0 paragraphs free Recently I returned to lDOS's memory allocation code that handles LMCBs and UMCBs. I'd intended to determine the amount of changes needed in order to make the allocation more compatible to MS-DOS v5, as in coalescing all free blocks in (only) the area being scanned. In particular, with COMPAT=NOCOLLECTALLMCBS, lDOS would end the scan early if a first fit match was found. MS-DOS would scan to the end of the area even for first fit. (For… text/html 2026-05-03T16:29:05+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0503_april/may_work?rev=1777818545&do=diff April/May work 2026-05-03 lDOS kernel * Replace entries in the int 21h DISPATCH table for user stack functions (33h, 50h, 51h, 62h, 64h) by servernoop which acts like a DOS v1 style error (AL = 00h, CF unchanged). This avoids the inevitable crash if one of these functions is called from a server call (int 21h function 5D00h). text/html 2026-04-28T18:56:23+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0428_late_april_work?rev=1777395383&do=diff Late April work 2026-04-26 lDebug * 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. tractest/convlist.pl * Improve use with gcc-compiled FreeDOS kernel, recognise .ptext and IB sections to set gccsections variable. Also, only dump hash_section_file_offsets once. text/html 2026-04-19T16:10:30+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0419_mid_april_work_on_intlist_and_the_list?rev=1776607830&do=diff Mid April work on IntList and the list 2026-04-19 webecm * Mention that TracList is written in perl. * Add section and news item for IntList. This refers to the new IntList only repo. IntList * Update the commandline with commands Space, Enter, Backtick, and Tab. * Refactor the big hyperlink regexp pattern and share it for all four users. Based on suggestions on perlmonks.org * Treat SF= as a register in hyperlinks, match it to REG = HEX subfn HEX text/html 2026-04-12T16:07:50+00:00 ecm (ecm@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. text/html 2026-04-06T15:10:08+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/blog/pushbx/2026/0406_early_april_work_on_the_list_ldos_boot/instsect?rev=1775481008&do=diff Early April work on the list, lDOS boot/instsect 2026-04-06 This week I contributed some to "the list", a project for updating Ralf Brown's Interrupt List. The RBIL was last updated on 2000-07-16. lDOS kernel * In the manual note that patldos is available both as an 8086 NASM DOS program and as a C program. text/html 2026-04-03T19:09:58+00:00 ecm (ecm@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 2026-03-30T09:28:43+00:00 ecm (ecm@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 2026-03-28T13:25:24+00:00 ecm (ecm@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 ecm (ecm@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 2026-03-22T17:57:58+00:00 ecm (ecm@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 2026-03-15T17:40:05+00:00 ecm (ecm@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 2025-11-04T16:41:44+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/?image=blog%3Apushbx%3A2025%3Acore04_blogo.png&ns=blog%3Apushbx%3A2025&rev=1762270904&tab_details=history&mediado=diff&do=media <img src="https://pushbx.org/ecm/dokuwiki/_media/blog/pushbx/2025/core04_blogo.png?w=320&h=200&t=1762270904&amp;tok=8dd961" alt="blog:pushbx:2025:core04_blogo.png" /> text/html 2024-02-14T17:33:38+00:00 ecm (ecm@undisclosed.example.com) https://pushbx.org/ecm/dokuwiki/?image=blog%3Apushbx%3A2024%3A20240211_175538653_030c.png&ns=blog%3Apushbx%3A2024&rev=1707928418&tab_details=history&mediado=diff&do=media <img src="https://pushbx.org/ecm/dokuwiki/_media/blog/pushbx/2024/20240211_175538653_030c.png?w=500&h=96&t=1707928418&amp;tok=47ecc8" alt="blog:pushbx:2024:20240211_175538653_030c.png" />