pushbx wiki

Enhanced DR-DOS single-file load

Anonymous (anonymous@undisclosed.example.com) — 2024-01-08T09:42:28+00:00

Enhanced DR-DOS single-file load 2024-01-07 As I had previously mentioned on the FreeDOS FDISK bug tracker on github, I went and combined the EDR-DOS kernel files to create a single-file load experience. I also described some possible advantages to a single-file load in the BT…

Late mid August work

Anonymous (anonymous@undisclosed.example.com) — 2023-08-21T20:20:36+00:00

Late mid August work 2023-08-20 The main developments this work occurred on the Enhanced DR-DOS codebase, which I collected into a repo before patching it. Some of the patches were contributed by a user of the BTTR forum. seekext The seekext TSR gained support for passing the file handle information service on int 21h function 71A6h to the redirector. This uses a dosemu2 extension service on int 2Fh function 11A6h, if available. This is particularly important for the 2011 revision of EDR-DOS…

How to create an iniload file carrying a DOS kernel

Anonymous (anonymous@undisclosed.example.com) — 2025-01-07T22:52:18+00:00

How to create an iniload file carrying a DOS kernel A user found that lDOS iniload was used in a certain boot image. After my answer identifying and describing iniload, the following question occurred in a comment: user pts, 2025-01-05 Building a native kernel The gold standard for building a complete, triple-mode kernel so that it is wrapped by lDOS iniload and optionally with an inicomp stage is

Early September work

Anonymous (anonymous@undisclosed.example.com) — 2024-09-10T19:06:11+00:00

Early September work 2024-09-08 The prior week nothing changed and that Sunday I didn't get to write a blog post regardless. This week some changes did happen. inicomp * Add _OPTIMISE_SMALL_INPUT define. Barely used yet. This actually sat in my repo for a while already but I only got around to committing it last Sunday.

Early mid July work

Anonymous (anonymous@undisclosed.example.com) — 2024-07-14T20:48:06+00:00

Early mid July work 2024-07-14 This week I started the ident86 project, which combines several parts to aid in comparing ports from one assembly language dialect to another. WarpLink The build using the mak.sh script now creates NASM listing files. These are for use with the convert listing files script.

Mid December up to early January

Anonymous (anonymous@undisclosed.example.com) — 2025-01-13T18:08:00+00:00

Mid December up to early January 2025-01-12 inicomp Upload an older patch to add a -B switch to the testfile program. This causes it to run an int3 breakpoint right before calling depack. webecm Add news item for lDebug release 9. ldosboot Optimise iniload some. This includes one noteworthy instance of abusing call to push the offset of something on the stack and branch elsewhere. Trying to Proceed past this call (using lDebug's P command) will fail.

Early mid September work on lDebug, EDR-DOS, and lDOS instsect

Anonymous (anonymous@undisclosed.example.com) — 2024-09-17T20:26:41+00:00

Early mid September work on lDebug, EDR-DOS, and lDOS instsect 2024-09-15 lDebug * Add structure for Extension for lDebug (ELD) trailer header * Support ELD trailer header in debugger's ELD loader * Support ELD trailer header in list.eld * Add eldapend tool to create a file with ELD trailer header pointing at an ELD *

Late September, early October work

Anonymous (anonymous@undisclosed.example.com) — 2024-10-13T17:59:13+00:00

Late September, early October work 2024-10-13 Last Sunday (2024-10-06) I travelled back from my partner's place, so I didn't get to write a blog post. Therefore we'll cover two weeks' worth of work today. kernwrap All of these changes were picked from lDebug.

Interlude: Current lDebug startup files

Anonymous (anonymous@undisclosed.example.com) — 2025-03-04T21:10:55+00:00

Interlude: Current lDebug startup files Something else for today: Because the Düssel-Café was closed for carnival last Sunday, today I want to list and discuss the ldebug.sld startup files that I have been using recently or not so recently. Plus, the scriptlet I use to enable booting different files in dosemu2 without having to move around a lot of files nor to re-configure dosemu2. This scriptlet allows to boot into lDebug's debugger command prompt rather than chainloading the FreeDOS kernel i…

December January work: Brief overview of the last 6 weeks

Anonymous (anonymous@undisclosed.example.com) — 2024-01-24T11:33:24+00:00

December January work: Brief overview of the last 6 weeks 2024-01-21 It's been a while since I got to write one of my regular blog posts. Hence, forgive me for being brief. TracList * Round parens are accepted as relocation markers throughout * Allow to highlight opcode after brackets in a line * Allow highlighting when a line ends in a dash after machine code * Allow a match after brackets/parens, but not if the match would start with a relocated value

Early August work

Anonymous (anonymous@undisclosed.example.com) — 2024-08-12T19:21:40+00:00

Early August work 2024-08-11 EIDL EIDL was a simple TSR that installed an int 28h handler which runs a hlt instruction, then chains to the prior handler. My adaptation of it combines the simple handler with the TSR example's multiplexer, as well as the optimal installation and advanced deinstallation method.

Mid late May work

Anonymous (anonymous@undisclosed.example.com) — 2024-05-21T19:34:19+00:00

Mid late May work 2024-05-19 lDOS MBR * Work around Book8088 / Xi8088 BIOS bug when detecting LBA * Optimisation: Do not zero CX after rep movsw * Normalise function 41h input al=dh=0 * Optimise: Share pushing DI before oldmbr CHS and LBA dispatch * Check for CHS overflow * Share setting DL after oldmbr CHS and LBA dispatch * Optimise: Make secpercyl a word, and re-use zero in DX * Drop CHS overflow check for last division, it is always passed

Mid to late July work

Anonymous (anonymous@undisclosed.example.com) — 2024-07-29T19:29:46+00:00

Mid to late July work 2024-07-28 The last two weeks I improved ident86 and used it to identicalise the Enhanced DR-DOS drdos module (ported to JWasm) as well as a new port of MSDebug to NASM. This new port re-used the fixmem.pl script from the WarpLink port to NASM.

freedos-devel mail on EDR-DOS single-file load, JWasm port, and ident86

Anonymous (anonymous@undisclosed.example.com) — 2024-08-09T17:51:14+00:00

freedos-devel mail on EDR-DOS single-file load, JWasm port, and ident86 Copied from my mail to the freedos-devel list. Hello Eric, hello list, On at 2024-07-26 13:04 +0200, Eric Auer via Freedos-devel wrote: " Hi! News from BTTR: while working on a single-file version of the EDR-DOS kernel,

Mid late August work

Anonymous (anonymous@undisclosed.example.com) — 2024-08-27T19:19:30+00:00

Mid late August work 2024-08-25 lDebug Bernd Böckmann requested a build of lDebug that can be booted on a machine with 256 KiB of low memory. I prepared smalll.sys, which can boot with as little as 192 KiB and leaves 86 KiB resident. This required a few changes: * Fix build with _EXTHELP=0 * Fix build with _EXTENSIONS=0 Unrelated changes: * Update copyright year in debug.asm, msg.asm, uu.asm, the online help page ?L, and the manual lDOS boot (experimental)

Much work in February/March

Anonymous (anonymous@undisclosed.example.com) — 2025-03-10T18:57:57+00:00

Much work in February/March 2025-03-09 As mentioned, last week I didn't get to write a proper blog post. So this one's about two weeks' worth of changes. SRDISK Fix the error handling in realloc_ems_handle. EMS doesn't set an error code in BL, and do not modify the indirect pages variable in case of error. inicomp Two changes to the test file program:

Drive letters beyond Z:, merged DOSENTRY and DOSCODE, disk full checks, trail binary

Anonymous (anonymous@undisclosed.example.com) — 2025-09-29T18:07:48+00:00

Drive letters beyond Z:, merged DOSENTRY and DOSCODE, disk full checks, trail binary 2025-09-28 This week I took on the support for the six drive letters beyond Z:, making lDebug, devload, SRDISK, MS-DOS v7, lDOS, EDR-DOS, FreeCOM, and dosemu2 able to use them. I wrote about this

Early November work

Anonymous (anonymous@undisclosed.example.com) — 2024-11-11T19:03:21+00:00

Early November work 2024-11-10 This week some work happened on Enhanced DR-DOS, lDebug, MSDebug, and MS-DOS. I was also involved in commenting on several stackoverflow questions. stackoverflow MS-DOS Debug misbehaves when writing to 1000h:0 A user attempted to assemble some code at 1000h:0 using the command

Mid September work on fixupp, instsect, and lDebug

Anonymous (anonymous@undisclosed.example.com) — 2024-09-22T17:53:41+00:00

Mid September work on fixupp, instsect, and lDebug 2024-09-22 This week some interesting developments occurred. fixupp This tool is a re-implementation of the ltools/fixupp.exe that was included in the OpenDOS 7.01 Machine Readable Sources package, as that was provided without sources. It operated on RASM-86 output object files to make them compatible with the object files assembled by JWasm. The exact purpose perpetually escapes me.

Early June work

Anonymous (anonymous@undisclosed.example.com) — 2024-06-12T21:47:10+00:00

Early June work 2024-06-09 lDebug The load_unit_flags equates are moved into iniload.mac, and a data link is added for load_unit_flags. The chstool Extension for lDebug will now use these flags. instsect Add flag _LBA_WORKAROUND to the LBA detection search strings. Not yet uploaded: Detect doubles in the LBA search strings, and eventually avoid writing them.

Mid to late October work

Anonymous (anonymous@undisclosed.example.com) — 2024-10-28T20:47:13+00:00

Mid to late October work I didn't get around to writing a blog post last week, so this one covers two weeks' worth of work. 2024-10-27 Instruction set reference Fixed insSTOSB stating that it "sets the flags accordingly". Also add to other string instructions that flags are not modified (ins, lods, movs, outs).

Late March work

Anonymous (anonymous@undisclosed.example.com) — 2024-04-02T19:39:56+00:00

Late March work 2024-03-31 lDebug * Do not use AX in LINKCALL ELD * Fix builds without history or with history in the data/entry segment * Fix, do not parse opening paren of linear address as part of the expression * Documentation updates EDR-DOS * Pick SvarDOS kernel patches since January * compbios, compbdos: Port to ia16 gcc with libi86 by using a far buffer for input (

Mid to late June work

Anonymous (anonymous@undisclosed.example.com) — 2024-06-30T17:33:11+00:00

Mid to late June work 2024-06-30 The last three weeks included a vacation time for me. I didn't do a lot of work during these two weeks. TracList An initial revision of the convedr.pl script. This only handles RASM-86 output files correctly so far, combined with WarpLink map files. After

Mid late January work (Enhanced DR-DOS, lDebug, lMS-DOS)

Anonymous (anonymous@undisclosed.example.com) — 2025-01-28T19:56:12+00:00

Mid late January work (Enhanced DR-DOS, lDebug, lMS-DOS) 2025-01-26 Enhanced DR-DOS A user reported that PC-DOS command.com (after hacking its version check) didn't work correctly running a REN command on EDR-DOS. I was able to reproduce the error, and found that it was present in OpenDOS v7.01 already (but not in DR-DOS v6.00 or

Early mid May work

Anonymous (anonymous@undisclosed.example.com) — 2024-05-12T20:31:02+00:00

Early mid May work 2024-05-12 wwwecm scripts Added msdos4 build. Added kernwrap as a dependency for edrdos and msdos4 builds. MSDebug Added the function checkend to the assembler, reject most cases of trailing garbage after the last accepted operand. Some cases remain, eg in, out, shifts and rotates. But many cases like mul, mov, xchg, push, and pop no longer accept trailing garbage.

Early July work

Anonymous (anonymous@undisclosed.example.com) — 2024-07-08T19:03:50+00:00

Early July work 2024-07-07 Enhanced DR-DOS * Add listing file output for dosgrps.asm * Fix: LFN search calling the redirector should not expect FAT+ size bits in the DTA * Fix: Address all new LFN variables using the BDOS_DATA segment instead of a mix TracList * convedr.pl: * extract function to process .rel file * allow lack of initial blank before offset of machine code dump * allow specifying explicit .rel files * subtract group base from segmented section address in …

Mid December: Last regular blog post of 2025

Anonymous (anonymous@undisclosed.example.com) — 2025-12-21T18:15:44+00:00

Mid December: Last regular blog post of 2025 2025-12-21 This is the last regular blog post of the year. There may be some irregular ones still. ident86 * Fix typos in the manual. * Fix screvid.but hyperlink to lead to the ident86 repo rather than lDebug's. Master Control Program * Add lDOS pre-boot loader to kernel payload, and allow loading it from the boot menu.

Mid late February work

Anonymous (anonymous@undisclosed.example.com) — 2024-03-03T17:09:54+00:00

Mid late February work 2024-02-25 This week some development on lmacros, instsect, lDebug, and EDR-DOS and FreeDOS happened. lmacros Add the fill_at_least macros to avoid an overflow in the debugger letting the entire build fail. Instead, the field will be filled if its content is shorter, but allowed to assemble as well if the content is as long as or longer than the fill length.

lDebug work in early April

Anonymous (anonymous@undisclosed.example.com) — 2024-04-08T19:51:40+00:00

lDebug work in early April 2024-04-07 Updates to the manual Only listing the most important changesets: * List INSTALL TOGGLE * List more INSTALL nouns (1, 2, 3) * Document L and W commands for sectors * Update vardco with 7th variables Code changes * init and qq will disable interrupts while relocating EBDA * bb: Many comments added and updated

Cleanup, InDOS, trampoline, INSTALLFIRST= lDOS kernel work in August

Anonymous (anonymous@undisclosed.example.com) — 2025-08-24T20:46:09+00:00

Cleanup, InDOS, trampoline, INSTALLFIRST= lDOS kernel work in August 2025-08-24 wwwecm scripts * Add tlsfiles to update script. * Always run mak.sh of tlsfiles, even if no update has been pulled. * Make tlsfiles an update_as_dependency * Also run mak.sh for update_as_dependency tlsfiles This repo collects all build dl wwwecm .tls files and logs them into hg for public read access using hgweb.

Late January work

Anonymous (anonymous@undisclosed.example.com) — 2024-01-29T18:08:56+00:00

Late January work 2024-01-28 Here's this week's work. lDebug dpb.eld * Add ADDRESS mode to specify address to read DPB from instead of a drive * Add EXTENDED= mode with FREEDOS, MSDOS, and EDRDOS keywords to select format * Add ONLY keyword to skip base DPB * Add LIST SKIP number and LIST DRIVE drive modes to use DPB pointer chain from the DOS List of Lists

Early mid August work

Anonymous (anonymous@undisclosed.example.com) — 2023-09-03T21:09:17+00:00

Early mid August work 2023-08-13 This week some development of the debugger and of dosemu2 happened. lDebug * Interrupt 0Dh, 0Ch hooks optional at run time (INSTALL INTFAULTS install flag noun) * Optional interrupt hooks share a lot of code now (1, 2, 3, 4) * In init the parsing of switches now capitalises the switch letter rather than doing two branches per switch

Mid August work (not much)

Anonymous (anonymous@undisclosed.example.com) — 2024-08-20T19:41:44+00:00

Mid August work (not much) 2024-08-18 fixmem * Call addequate for section or group names listed in WRT clauses, and add section or group name to the equates structures Enhanced DR-DOS Finished port of drbio to NASM. ident86 * Add -f switch to change or increase default fuzzy compare equal delta limit (from default 32)

Early December work

Anonymous (anonymous@undisclosed.example.com) — 2024-12-11T14:30:36+00:00

Early December work 2024-12-08 Today marks the 100th blog post that I wrote on the HP 95LX. It also is likely to be the last post in December due to the café closing for a few weeks starting tomorrow. lDebug The lDebug repo got updated some. *

August / September work

Anonymous (anonymous@undisclosed.example.com) — 2023-12-04T20:47:07+00:00

August / September work 2023-09-03 Some work on EDR-DOS and lDebug happened. A manual for TESTHOOK has been added. Additionally, some experience using lDebug was gained. EDR-DOS During testing of building Enhanced DR-DOS from within itself (running in dosemu2, either on MFS-redirected drives or on a FAT32 hard disk image) it turned out that EDR-DOS's command.com does not support the /Y switch to the COPY command. I had used that switch for FreeCOM in order to copy the

Late August work

Anonymous (anonymous@undisclosed.example.com) — 2023-08-28T21:25:47+00:00

Late August work 2023-08-27 This week some development happened. I also finished an audit of all lDebug changes in recent months and did a pass over the entire lDebug manual to update the worst outdated parts. Finally, I prepared the lDebug release 6 yesterday. MSDebug changes The range parameter type's manual entry

Support of segment overrides for XLATB

Anonymous (anonymous@undisclosed.example.com) — 2024-07-01T19:47:03+00:00

Support of segment overrides for XLATB Copied from a mail sent to freedos-devel: On at 2024-06-30 23:04 +0200, Bernd Böckmann via Freedos-devel wrote: " Hello, I have a question our assembly people: I stumbled upon an unusual instruction in the EDR-DOS source [1]. In RASM86 this is expressed as

October November work on porting the MS-DOS v4.01 kernel

Anonymous (anonymous@undisclosed.example.com) — 2024-11-04T18:13:29+00:00

October November work on porting the MS-DOS v4.01 kernel 2024-11-03 Today I finally uploaded the first steps toward porting the free software MS-DOS kernel (released on 2024 April 26) to build with NASM and WarpLink (and x2b2 and round and convlist.pl). So far only one file has been ported.

Late February work

Anonymous (anonymous@undisclosed.example.com) — 2024-03-03T17:22:46+00:00

Late February work 2024-03-03 This week some development happened on lDebug, inicomp, and ldosboot. (At the time of this writing, the prior blog post still isn't released. Oh well.) The SvarDOS repo for Enhanced DR-DOS had some discussion about compression formats. lDebug * Work around old Exomizer incorrectly checking its -P switch, by doubling it

Early September work

Anonymous (anonymous@undisclosed.example.com) — 2025-09-14T17:48:05+00:00

Early September work 2025-09-07 fixupp To help port the default overlay manager of WarpLink to NASM, we had to use symbols starting with a dollar sign. But NASM didn't support those. (In the upcoming NASM v3.00 some support has been added.) To bridge this gap, I modified the trusty fixupp utility once again. It will now replace one or more leading "D." in section, class, or symbol names by a dollar sign each.

MS-DOS v3.40 versus v4.00

Anonymous (anonymous@undisclosed.example.com) — 2025-05-01T18:00:11+00:00

MS-DOS v3.40 versus v4.00 I have recently referred to the "v3.40 branch" of MS-DOS. This refers to the v4.00 and v4.01 versions that are well known and that have shipped most sources in the 2024 April release. The v3.40 distinction is as opposed to the "European MS-DOS v4.00", "Multitasking MS-DOS", or

Mid early March work

Anonymous (anonymous@undisclosed.example.com) — 2025-03-17T19:42:29+00:00

Mid early March work 2025-03-16 Only some updates to the lDOS kernel, and supporting tools. One changeset from last week uploaded to the lDebug repo. kernwrap Add an option to disable building of the version.com utility. This is needed to include the COM loader into ldos.com, which requires building version.com before this point.

Restoring modified files from NASM listing files

Anonymous (anonymous@undisclosed.example.com) — 2025-12-23T21:41:09+00:00

Restoring modified files from NASM listing files I accidentally reset a repo using the hg strip -f command, which destroys unsaved changes in the current working directory. I still had the original .lst listing files created by NASM, however. These turned out to be expressive enough to completely restore the deleted changes in this case.