Assembly Studio 1.0.1

Installer: AssemblyStudio-1.0.1-setup.exe (53.5 MB)
SHA-256: 17f4f02ed28c69f0a155f2106ab76d7a3303b424e4a15026c2efa5d780990370

The installer is not code-signed, so Windows SmartScreen may warn before running it (choose More info, then Run anyway). Check the hash first with Get-FileHash .\AssemblyStudio-1.0.1-setup.exe. If you have 1.0.0, run this installer over it: your settings are kept. See docs/09-release/install-guide.md.

Highlights

• Write, build, run and debug 8086 assembly programs for DOS (.COM), in one window, fully offline.
• NASM 3.02 is included. A new installation builds and runs the samples with no setup.
• Step through programs and watch registers, flags, memory, the stack and your variables change. Changed values are marked.
• Samples, tutorials, an instruction reference and help are built in.
• Free and open source under the MIT License.

What's new in 1.0.1

• Assembly Studio has its own logo, NASM's memory brackets around the debugger's execution arrow, [▶]. You'll see it on the
  program, the taskbar, the title bar, the Start menu and the installer.
• Nothing else changed: the features, the supported scope and the known limitations are those of 1.0.0.

Features (since 1.0.0)

Feature	Requirements
Files: new from a template, open, save (atomic), tabs, recent files, unsaved-changes prompts, crash recovery of unsaved edits	FR-001..FR-008, FR-019, FR-020, NFR-011
Editor: NASM syntax highlighting, line numbers, current line, undo/redo, block indent, find, replace, go to line, zoom	FR-011..FR-017, FR-022
Build with the bundled NASM: diagnostics on the source lines, a hint for MASM/TASM syntax, clear errors with a next step	FR-018, FR-021, FR-023..FR-032, FR-065, FR-066
Run inside an emulated 8086 PC (1 MB, real mode): Run, Pause, Stop, Reset, an instruction budget; the IDE never freezes	FR-033..FR-042, FR-067, FR-095, FR-096
DOS text services: INT 21h functions 00h, 01h, 02h, 07h, 08h, 09h, 0Ah, 4Ch, INT 20h, Ctrl-C; a console panel with keyboard input	FR-039..FR-041, FR-063, FR-064
Debugging: Step Into, Step Over, breakpoints, current instruction with disassembly, execution history	FR-049..FR-053, FR-057, FR-058
Panels: registers (with 8-bit halves and number formats), flags, memory (hex and ASCII), stack, variables	FR-046..FR-048, FR-054..FR-056, FR-097
Learn: 8 samples, 5 tutorials, an instruction and concept reference, help pages	FR-045, FR-068..FR-072
Settings: assembler path, editor and execution preferences, reset; About with diagnostics, release notes and notices	FR-075..FR-082, FR-087, FR-090
Accessibility: keyboard for every workflow, visible focus, screen-reader names and announcements, dark, light and high-contrast themes	FR-091..FR-094

Fixes

None in 1.0.1.

Supported scope

• Processor: Intel 8086 in real mode with 1 MB of memory. Every documented 8086 instruction except IN, OUT and the 8087 (ESC)
  instructions. 80186 and later instructions are not supported.
• Assembler: NASM syntax, assembled by the bundled NASM 3.02. A different NASM, 3.02 or later, can be set in Settings.
• Programs: DOS .COM programs of up to 65,278 bytes, starting at offset 100h.
• Services: the DOS functions listed above. No files, disks, clock, memory allocation or BIOS services.

Known limitations

• First start after a Windows restart: can take several seconds (about 8 seconds was measured on an Intel Core i5-8265U).
  Later starts take under 2 seconds.
• Variables panel: NASM doesn't record what a label's data means, so a 1-byte variable is shown as a byte and a 2-byte one
  as a word, even a text such as db 'OK'.
  • At most 64 bytes of a variable are shown; a longer one shows its first 64 bytes in hex followed by "…".
  • Variables are read in at most 2 regions of 4,096 bytes. A variable outside them shows "(not shown: too far from the other
    variables)".
• Program size: .COM programs can be up to 65,278 bytes (64 KiB minus the 256-byte PSP and the 2-byte stack word). Real DOS
  allows 65,280.
• Processor: 8086 only. IN, OUT, the 8087 (ESC) instructions and instructions of the 80186 and later are not supported; the
  help page "Unsupported instructions" lists them.
• Programs: DOS .COM programs only. No .EXE programs, segments, or linking several source files.
• DOS and BIOS services: only the INT 21h functions listed above, INT 20h and Ctrl-C (INT 23h). No files, disks, date, time
  or memory allocation, and no BIOS services (INT 10h, INT 16h and so on).
• Input and output: text only, through the Console panel. No graphics, sound, mouse, timer or printer.
• Assembler: NASM syntax only. MASM and TASM syntax is not accepted.
• Tested systems: this release was tested on one Windows 11 PC. Installing on a clean machine and running on Windows 10 LTSC
  were not tested.
• Not yet tested with users: the planned first-use session with new users hasn't been run.
• English only.
• The installer is not code-signed, so Windows may warn before running it (see the install guide).

System requirements

• Windows: 64-bit Windows 11, or Windows 10 version 21H2 (build 19044) or later. Only Windows 11 was tested.
• Disk: about 190 MB. The installed size is 185 MB.
• No .NET installation needed: the runtime is included. Nothing is downloaded, during installation or afterwards.

Installation and upgrade

Run AssemblyStudio-1.0.1-setup.exe and accept the license page. It installs for the current user and needs no administrator
rights. If you have 1.0.0, run the 1.0.1 installer: it installs over 1.0.0 and keeps your settings. Uninstalling removes the program but never your
source files or settings. See docs/09-release/install-guide.md.

Third-party components

Assembly Studio includes:

• the Microsoft .NET runtime and WPF;
• AvalonEdit, CommunityToolkit.Mvvm and Iced;
• NASM 3.02.

Their licenses are in THIRD-PARTY-NOTICES.txt in the installation folder, and in Help → About → Third-party notices. Six .NET
files are under Microsoft terms, which you accept on the installer's license page.