GSSquared v0.11.0 Released

Posted by: A.P.P.L.E. Date: August 25, 2026 0 Likes 5 Views

I am pleased to announce the release of GSSquared v0.11.0.

GSSquared is an Apple II series computer emulator.

Supported platforms
  • Apple ][
  • Apple ][ Plus
  • Apple //e
  • Apple //e Enhanced
  • Apple //e Enhanced with 65816 CPU and Super Hires Video
  • Apple IIgs ROM 01
  • Apple IIgs ROM 03
Pre-built binaries
  • macOS (Intel and Apple Silicon)
  • Windows 10+
  • Linux AppImage (should run on many Linux distros; tested on Ubuntu 22)

This release is about connecting the virtual machine to the real one — host serial ports, print-to-clipboard, Host FST on Windows — and about display and accuracy: CRT shaders on Windows and Linux, Second Sight Apple II text, CD-ROM / APM volumes, and a large round of IIgs timing and MMU fixes (including textfunk). The debugger can snapshot video pages, and the debug protocol now works on Windows.

Features
  • Host Serial. Attach a real host UART to IIgs SCC or Super Serial from the Control Panel or config editor: macOS /dev/cu.*, Windows COMn, Linux /dev/ttyUSB* / ttyACM* / ttyAMA* (Bluetooth/debug callouts skipped). Guest baud, data, parity, and stop bits pass through. Unplugged dongles stay attached and retry.
  • Print to clipboard. Serial and parallel ports can attach a Clipboard device. Guest output is buffered, high-bit stripped, and copied to the host clipboard after idle-close (~10s) or Ctrl-Reset, with a toast for the byte count.
  • CRT shader on Windows and Linux. The CRT GPU effect (already on macOS) is available on Windows (D3D12 / DXIL) and Linux (Vulkan / SPIR-V). Toggle with Display → CRT Shader or F7. Prebuilt shader blobs ship with the app; extra compiler SDKs are not required to build.
  • Host FST on Windows. Share a host folder with GS/OS as :Host on 64-bit Windows. ProDOS type/auxtype, Finder info, and resource forks are stored in NTFS Alternate Data Streams (use an NTFS folder).
  • Second Sight Apple II text. With a Second Sight card, Display → Second Sight Text renders Apple II 40/80-column text through the card’s VGA path (Apple-ified font from the Second Sight ROM).
  • CD-ROM / APM on BazFast. Mount .iso CD dumps (always write-protected). If the image has an Apple Partition Map, each ProDOS and HFS partition appears as its own SmartPort unit — the usual path for 1990s Apple IIgs CD-ROMs.
  • IIgs paste. Edit → Paste Text and Shift+Insert now work on IIgs ADB, matching the existing II/IIe path: one character per frame so the guest can keep up.
  • Debugger video pages. The debugger Video pane can decode a specified display page (hgr1, 80text1, SHR, …) as a static thumbnail while you step.
  • Drivers volume. File → Mount Drivers still mounts /GS2.DRIVERS. The installer on that disk has options to install Host FST, Marinetti, and Uthernet II.
Accuracy
  • IIgs FPI registers ($C035–$C037, $C02D, $C068, $C071–$C07F) are billed as fast cycles instead of 1 MHz Mega II accesses — textfunk display timing is correct.
  • Ludicrous speed is now fixed multiples of the 14 MHz clock so the video scanner still runs. Speaker, Ensoniq, and related devices no longer fall apart under LS.
  • 65816 / 6502: WAI implementation; PLB is 4 cycles (was 2); XCE is 2 cycles (was 1); native-mode relative branches no longer take a page-cross penalty (ROM 03 beep pitch).
  • ROM 03 keyboard repeat rates above default are no longer extremely slow.
  • IIgs MMU: bank $E1 language-card decode; linearization and shadow fixes; ROM 03 cold-start reset; banks $F0–$FF treated as fast ROM.
  • GS/OS mouse tracking on 640-pixel SHR desktops no longer tracks as 320.
  • Second Sight VBL is generated in text mode under ludicrous speed (GNO/ME no longer freezes).
Bug Fixes
  • .2mg images with missing or zero header parameters no longer truncate or misread; header sanity checks are stronger.
  • BazFast refuses 140K floppy images (those belong on a 5.25″ drive) and will not mount the same host file more than once.
  • File → Quit now works on Windows (enabled at System Select; use Close Emulation while a machine is running).
  • Debugger monitor pane jumps to the newest output after a command instead of staying scrolled to the top.
  • Windows path handling in system settings is more reliable.
Internals
  • Debug Protocol listens on Windows AF_UNIX sockets (--debug on Win10+). New/extended commands: mount/unmount storage, linearized text-page capture, get/set CPU registers, and PASTE_TEXT (Python paste_text) so agents can fill the paste buffer in one round-trip.
  • Debugger user guide: UsingTheDebugger.md.

You can download the latest release of GSSquared from the Github page at:
https://github.com/jawaidbazyar2/gssquared/

Author: A.P.P.L.E.
The A.P.P.L.E. Website is run by the Apple Pugetsound Program Library Exchange Users Group and is open to all Apple and Macintosh fans and their friends.
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