So it is basically exactly like MS-DOS Player, but more accessible to us Westerners. I am looking forward to trying it!

mattnz wrote on 2025-05-27, 09:29:

Hi all,

I started out wanting to write a 8086/8088 .OBJ file unit test framework, but got side tracked by the ability to run MS-DOS command line programs on my Apple Silicon Mac. I've concentrated on getting Borland development tools working, so the following runs successfully in your command shell/terminal: Turbo Assembler 3.2, Turbo Linker 3.0.1, Turbo Librarian 3.0, Turbo Pascal 5.5 & 6.0, and a program from Fabrice Bellard called INFOEXE.

This is really cool!

mattnz wrote on 2025-05-27, 09:29:

The CPU emulation is rock solid due to it passing Single Step Test suite's 2.5 million tests - 10,000 per opcode (thanks to Daniel Balsom/MartyPC).

Glad you found them useful! It's always great seeing another emulator take advantage of them.

Ringding wrote on 2025-05-27, 13:49:

So it is basically exactly like MS-DOS Player, but more accessible to us Westerners. I am looking forward to trying it!

I hadn't come across that particular bit of software before, probably because it's Windows only, and I'm pretty much entirely on Mac these days (for my day job requirements). MS-DOS Player is obviously a way more feature complete emulation and handles full screen text mode DOS programs.

Let me know how you get on and what other programs you'd want to run. I'll probably look into getting Microsoft Assembler + Linker running at some point.

GloriousCow wrote on 2025-05-27, 17:26:

Glad you found them useful! It's always great seeing another emulator take advantage of them.

I wouldn't had bothered writing this if the test suite wasn't available. Like everyone else on this forum, it's been 35 years since i've done any 8086 assembler so I was very rusty on all the opcodes, segmented memory addressing etc. I must get on with implementing my unit test framework now, the original goal.

1.0.1 now released with updated xt (macOS/Linux) and xt.bat (Windows) scripts to allow running XT from anywhere on your system (assuming PATH is set).

Quick update. I've converted several scans of the 8086 Relocatable Object Module Formats PDF's into an editable Word document named OBJ.docx (and then saved that as a readable PDF named OBJ.pdf). So for anyone (like myself) interested in the .OBJ format from Turbo Assembler etc, this is super useful. Files are in the doc/ directory of the xt repo.

GitHub: https://github.com/electricbolt/XT/blob/main/doc/OBJ.pdf

obj is "ugly child". Also, avaible "Microsoft OBJ" and "Borland OBJ". Yes, all of them support one format. But in own way.
Check this:

https://github.com/DosWorld/rtools
https://github.com/DosWorld/rtools/blob/maste … /DOC/RDOFF2.TXT
http://github.com/DosWorld/rtools/tree/master/EXAMPLES

Hi all,

I've released version 2.0.0, which has been rewritten entirely in Swift, and therefore now only targets macOS 26+ (Apple Silicon only). New in this version:

* Same super friendly developer experience for adding new interrupt handling using a combination of Swift property wrappers and annotations:

1@Interrupt(function: 0x09, description: "Write string to standard output")
2func writeString(_ cpu: CPU, @ASCIZ(terminator: "$") @DS @DX _ s: String) {
3  Foundation::write(STDOUT_FILENO, s, s.count)
4  cpu.reg.AL.setValue(("$" as Character).asciiValue!);
5}

* Installed via macOS package (signed and notarized). Automatically installs "xt" to /usr/local/bin.
* Now runs MASM 5.10, LINK 3.65 and Undocumented DOS book's MEM.EXE.
* Larger integration test suite.
* Ability to convert MS-DOS command line programs into native macOS apps. e.g. "xt app MASM.EXE masm".
* The CPU emulator is now a Swift Package (https://github.com/electricbolt/xt-swift-cpu8088) available to import into other projects as required.

https://github.com/electricbolt/xt-swift-user … .0/xt-2.0.0.pkg

mattnz wrote on Today, 00:15:

and therefore now only targets macOS 26+ (Apple Silicon only).

Hi, that makes sense, though I really hope there's a future chance to get Swift/Xode 27 to produce applications that will run on Sequoia 15.6+.
Because macOS 26 with the rounded corners is ugly.
It would be a bit depressing to think that good software now requires macOS 26+. IMHO.
But of course, that's a bit off-topic. Please never mind.

Edit: I've searched the web a bit and there's an undocumented switch that enables Xcode 27 Beta to compile to old OS targets again (pre OS X 12).
So maybe, eventually, there's some hope for Swift, too.