martypc

0.4.0 (2025-05-11)

This update brings a massive list of new features, so here's a quick summary:

• New sound system and sound devices including Adlib, Disney Sound Source, and SN76489 3-voice sound
• New floppy disk image library enabling a ton of new floppy disk image types and support for several copy protections
• New frontend supporting both native and WASM, support for native file dialogs
• ATA device emulation, supported by XT-IDE and jr-IDE devices for larger hard disk support
• VGA support and improved PCjr and TGA video emulation
• Memory and register editing

New eframe Frontend

Some dependency API changes prompted me to switch window frameworks. The active Desktop frontend for MartyPC is now based on a customized fork of eframe.

Native File Dialogs

• The RFD crate provides access to native file dialogs for your particular OS, including File Open and Save dialogs.
• Startup errors are now reported via a system MessageBox. You should no longer have to rely on the command line output to tell why MartyPC didn't start.

New Devices

• VGA

  • The IBM VGA card is emulated at last. MartyPC's VGA is based off its EGA implementation, with appropriate changes and additions. Clocked up to 28Mhz, the VGA is an expensive device to run at a character-clock accurate rate, so you may need a fast computer. Mode 13h and ModeX/Y are supported (Wolfenstein 3D's 'ModeY' works!).
  • The Video Card debugger window will show you the VGA's register state, including the current palette in realtime.

• XTIDE Hard Disk Controller

  • An XTIDE Rev 2 device can now be emulated. Since this BIOS is open-source, a machine configuration that includes hard drive support is now the default: ibm5160_xtide.
  • If you want the 'authentic retro' experience, the IBM/Xebec controller is still available as ibm5160_hdd as usual.
  • The VHD creator has been updated to support the wide selection of common hard drive geometries that the XTIDE can support. You'll need to be running a machine with the XTIDE configured to see them.
  • It is now possible to take a VHD file from 86Box (assuming you created it as a 'fixed' VHD) and use it in MartyPC (and vice versa!).

• jr-IDE Hard Disk Controller

  • To go along with the XTIDE, you can now emulate the jr-IDE. This gives you LBA-enabled ATA hard disk support and 736k of conventional memory backfill for your PCjr.

• Adlib Music Card

  • The first audio device in MartyPC besides the PC speaker is the Adlib Music Card. OPL2 emulation is provided by the highly-accurate nuked-opl3 library.

• SN76489

  • The 3-voice sound chip found in the IBM PCjr and Tandy 1000 will be automatically installed on these machines.

• Disney Sound Source

  • If you have a parallel adapter specified, you can attach a Disney Sound Source, and enjoy various squawky digitized sounds in games that support it (Mostly Disney titles, Wolf 3d, Prince of Persia, and a few others. See Mobygames for a list of supported titles).

• Memory Expansion Cards

  • Conventional memory expansion cards can now be specified, at any address and with any capacity. It is possible to have non-contiguous memory regions if you decide to do so, but caveat emptor.
  • An overlay for the IBM PCjr called 'pcjr_memory_sidecar' will provide an extra 512k to bring your PCjr up to 640k.

Bitstream-level Disk Image Emulation

The inclusion of the fluxfox disk image library has greatly expanded MartyPC's floppy disk image support, and enabled support for several copy protection schemes.

Disk Image Support

Fluxfox supports reading a wide array of disk image formats:

• TD0 (TeleDisk)
• IMD (ImageDisk)
• PSI (PCE Sector Image)
• TC (TransCopy Image)
• PRI (P

MartyPC 0.2.2 is here!

Known Issues

• You may get a Windows SmartScreen notification that this application is 'unknown'. You will need to click 'run anyway'. The MartyPC Windows executable is signed via Sectigo; I have done all I can think of to appease Microsoft, and not sure what else to do. This is NOT a malware warning.

• WGPU support for older GPUs has moved from DirectX to OpenGL. If you are running an older graphics card or integrated graphics adapter and experience poor performance, please set the following user environment variable:

WGPU_BACKEND=gl

• macOS users on Intel may experience colored stripes on the screen in fullscreen mode. Enable macos_stripe_fix in the configuration to resolve this.

New devices

• LoTech 2MB EMS Board

  • Added emulation of the LoTech 2MB EMS Card This card can be added to any machine configuration via the lotech_ems overlay. You can specify the window segment and IO base address. However, these values must match one of the values supported by the real hardware or the driver won't work with it.

• Game Port and Joystick

  • Added emulation of the IBM game port card, and basic keyboard-based joystick emulation. There is a new keyboard hotkey (JoyToggle) to turn this on and off (provisionally defined as Ctrl-F9), as well as configurable joystick_keys in the configuration you can use to define what keys control the joystick.
  • PCJr and Tandy 1000 machines will have a game port installed automatically. You can add a game port to any PC or XT configuration via the game_port overlay.
  • Two two-button, two-axis joysticks are assumed to be connected when you specify a game port. Different joystick configurations may be supported in the future.

• PCJr Cartridge Slots

  • Added support in the core, frontend and GUI for PCJr cartridges in JRipCart format. Inserting or removing a cart will reboot the machine. You will only see the cartridge slots when using the PCJr machine.

Frontend Bug Fixes / Improvements

• Added a new resource type 'cartridge' and menu interface to browse and select PCJr Cartridges.

Core Bug Fixes / Improvements

• SERIAL: Fixed many issues in MartyPC's 8250 UART emulation. PCjr now boots without error code 'D' and Checkit2 serial diagnostics also pass.
• BUS: Implemented a terminal_port configuration option under [machine] in the main configuration. Writes to this port will be printed to the host's terminal.
• MC6845: Fixed an issue preventing entering vertical total adjust period if vertical total was 127. Fixes some Hercules display issues.
• HERCULES: Increased the size of the Hercules' display field to accomodate some CGA emulators that drive the MDA monitor slightly out of sync (Fixes BBSIMCGA)
• CGA: Added CGA's external mode register to debug output
• MACHINE: Added a facility to record disassembly listings from running code. The output filename is set by disassembly_file under [machine] in the main configuration. Basically, this feature saves instruction disassembly to a hash table by CS:IP. Modification of code segments will override previous disassembly, so it is most useful to toggle this feature on and off for specified periods.

Debugger Bug Fixes / Improvements

• Serial Status window: Displays serial port registers and statistics.
• IO Status Window
  • Added a 'reset' button to reset all the port counters.
  • Added the last read byte value for each port
  • Fixed panic/crash when resetting machine with the IO Stats window open and scrolled.

Distribution Changes

• Added a SvarDOS-based MartyPC boot diskette to media/floppies/boot. This disk will load the LoTech EMS driver and CTmouse driver.
• Moved FreeDOS to media/floppies/DOS
• Added SvarDOS build 20240201 diskettes to media/floppies/DOS
• Added ctmouse

MartyPC v0.2.1

MartyPC v0.2.1 contains dozens of bugfixes, accuracy improvements, new debugger features, a new CPU (NEC V20), new video cards, machine types and more!

New BIU logic

• 0.2.0 introduced new BIU logic. Unfortunately, 0.2.0 took so long that this 'new' logic already needed replacement. With the discovery of the 8088's 7-cycle bus access time, far simpler BIU logic is possible and has been implemented in 0.2.1. For more information, see my corresponding blog post.

• Along with this new logic comes a slightly different cycle log format; I'm probably the only person on earth that reads these logs, but it's worth mentioning. Several old state columns are gone, and now bus and T-cycles are displayed within two separate 'pipeline slots'.

New CPU Framework

• MartyPC now has a framework to support multiple CPU types, so we can have CPUs other than the Intel 8088. There is a slight performance hit involved in not hardcoding a specific CPU, but I believe there are some strategies I can use to mitigate this.

New CPU Type

• An initial implementation of the NEC V20 has been added. All native-mode V20 instructions are implemented (except BRKEM). This is not cycle-accurate yet, as it was copied and modified from the 8088.
• The Arduino8088 project and the test generation engine of MartyPC were refactored and improved to enable generation of a CPU test suite for the V20, which will be used to incrementally improve V20 emulation accuracy over time. 8080 emulation mode will be added in the future. The V20 test suite can be found here.
• You can add a V20 to any 8088-based machine by adding the cpu_v20 overlay.

New Machines

• Added Tandy 1000 and IBM PCJr machine types and ROM definitions. These are still very much a work in progress.
  • Tandy 1000 is mostly functional, and can accept a ibm_xebec hard disk controller (I will eventually dump the Tandy hard disk controller ROM, but it is a Xebec controller).
  • IBM PCJr needs cartridge browser support and PIO mode implemented for the floppy disk controller.
    • RAW cartridge images can be loaded as ROMs using the standard ROM definitions; however this is less than ideal. I will be adding support for standard PCJr ROM dump formats.

New Video Types

• To go with these new systems, there is now a TGA graphics type. Again, a work in progress.

  • Tandy BIOS identifies the TGA and will boot into 8x9 text mode. Display apertures were tweaked for TGA to support this "tall" mode.
  • TGA adapter operates very differently from other adapter types as it does not have its own VRAM.
  • New core functionality was required to allow mapping of MMIO reads and writes back to system memory.
  • High-resolution 640x200 2bpp mode not yet implemented.

• PCJr graphics are implemented as a subtype of TGA adapter

• Initial support for Hercules graphics card as a subtype of MDA adapter. Still a bit glitchy.

Frontend Bug Fixes / Improvements

• Added missing overlay for dual 360k floppy configuration (thanks DragomirPazura)
• Fixed loading of keyboard mapping files
• Added CPI (Cycles Per Instruction) to benchmark mode.

Debugger Bug Fixes / Improvements

• Added cycle stopwatch UI to CPU Control window. The stopwatch allows you to set two 'breakpoints' and measure execution time between them.
• 'Step-over' logic overhauled. Step-over cycle timeout removed. A step over may not terminate, but this is in line with other debuggers. On further feedback, dropping you off in a random location after timeout was not useful.
  • The expected return address will be displayed in the CPU Control window in the event a step over does not return.
• You can now step-over rep string operations.
• Re-entrant instructions such as rep string

It's been nearly 9 months since the last release of MartyPC. During that time I have rewritten or refactored much of the emulator. Check out this enormous changelog!

Lots of new features mean lots of new bugs, though. I expect a bugfix 0.2.1 will follow shortly. Hopefully, MartyPC now has a much better framework for more frequent releases going forward.

New Features

• New Display Manager Framework

  • New graphics backend abstraction layer will eventually allow frontends built for other graphics backends such as SDL
  • New scaling modes: Choose from Fixed, Integer, Fit and Stretch scaling options
  • Display Apertures: Choose how much of the emulated display field you wish to see:
    • No overscan
    • 'Monitor-accurate' overscan
    • Full overscan
    • Full display field including hblank and vblank periods (for debugging)
  • Hardware aspect correction: Aspect correction is now performed in the shader for reduced CPU load
  • Multi-window support: Define additional output windows in the configuration file
    • Multiple windows can display the same video card, with different display options
    • Windows can be set to a fixed size or scale factor, or made completely resizable
    • Windows can be pinned 'always on top'
    • Windows can be toggled full-screen via CONTROL-ALT-ENTER hotkey
  • Shader support: A basic CRT shader is built into the new display scaler
    • Internal shader features:
      • Barrel distortion
      • Corner radius (rounded corners)
      • Monochrome phosphor simulation
      • Scanline emulation synchronized to emulated video resolution
    • Presets for the internal scaler can be defined in configuration and applied to different windows

• New ROM Definition Framework

  • ROM set definitions are no longer hardcoded. They will be read from ROM set definition TOML files in the ROM directory.
  • Add your own custom ROM sets or contribute missing ROM definitions to MartyPC!

• New Machine Configuration Framework

  • Define multiple Machine hardware configurations, name them, select them in the main config or via command line argument.
  • Configure the amount of conventional memory, the number and type of floppy drives, video cards, serial ports and more!

• New Resource Manager Framework

  • Paths are to 'resource ids' are now fully configurable, and facilities to build file trees are provided. MartyPC can create needed directories on startup. The Floppy and VHD browsers have been rewritten to take advantage of this new system, and so now you can organize your media directories into subdirectories for convenience.

• EGA Video Card

  • EGA is back! A character-clocked EGA implementation is here, although it may still be a bit rough around the edges. EGA will continue to be polished in upcoming releases.
  • Features:
    • Functional emulation of each of the 5 LSI chips on the EGA
    • Per-scanline Pel panning - effects like the wibble in Beverly Hills Cop work
    • Line compare register - See the status bar in Catacombs 3d!
    • CGA compatibility mode - Play Alleycat!
    • Software fonts - change your DOS font, or see a graphical mouse cursor in text mode (Norton Utilities 6.0)
  • Known issues:
    • Visual glitches with n0p's Windows 3.0 EGA driver patched for 8088
    • Some more obscure registers not properly emulated / investigated (SOM, etc.)
    • Aperture definitions / adjustments not final
    • Implementation may be slow in parts - more optimization needed (SIMD?)

• MDA Video Card

  • Not quite as a flashy as EGA, but the MDA card type is now also supported, and moreover, you can install an MDA alongside a CGA or EGA card for a dual head display.
  • 9th column rendering and underline attr