4.01 / 21-02-2022
Altirra
Accuracy
Performance
Features
Altirra is a full cycle-exact emulation of all documented hardware features for the Atari 400/800, 1200XL, 600/800XL, 130XE, XEGS, and 5200 systems and is particularly notable for having a very well equipped debugger tool.
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Windows: XP SP3+ for x86/x64
Qualcomm Snapdragon 835+ for ARM64
Most Recent Changes
--4.01--
Bugs fixed
Additions: Fixed LOADEXE.XEX using old $FD device SIO code for the program loader instead of $7D.
AltirraOS: Fixed math pack compatibility issue with FDIV modifying FLPTR (fixes B-Graph pie chart routine).
AltirraOS: Fixed a cursor position checking bug with split screen Gr.0 (fixes the BASIC game House of Usher).
AltirraOS: Fixed compatibility issue with KEYDEL handling (fixes cursor movement in BrushupV40).
ATBasic: IOCB#7 is now automatically closed on I/O errors to avoid SAVE files being kept open for write.
Cassette: Fixed FLAC decoder crash with some block sizes.
Cassette: Fixed regression with FSK blocks in CAS files being read as turbo pulses instead of FSK pulses.
Disk: Retuned XF551 high-speed C/E to data frame delay.
Display: Workaround for D3D11 minimum precision crash on Intel Iris Xe 30.0.101.1069 driver.
Serial: Pad out 850 relocator to match length of original firmware relocator (fixes compatibility with loaders that hardcode the relocator length).
VFS: Fixed wrong file being accessed when using atfs:// paths to access files inside a DOS 2 disk image.
--4.00--
Tape: New turbo support, tape editor, and support for loading raw tapes directly from .flac files.
Disk: Atari 815 emulation, 8" disk geometry support, Disk Explorer can now access files in Indus CP/M images, many full disk drive emulation fixes.
Display: Palette solver, monochrome mode, HDR display support, ANTIC fixes.
Sound: Improved audio filtering, automatic output switching when using WASAPI output, POKEY fixes.
Input: Preset template generator for making input maps, low-latency paddle option, retuned trackball speeds, 5200 fixes.
Devices: Percom AT88-SPD, SIDE 3, 1090 80-column board, Bit 3, virtual FAT16/FAT32/SDFS hard disk; modem, XEP80 and Rapidus fixes.
UI: Improved dark mode theme support.
Debugger: Memory window upgraded with variable width, type, and graphics decoding support; improved speed, more banked cartridge debugging support, improved 65C816 native mode support, more timestamped logging options, and more verifier options.
--3.91--
bug fix release for the 3.x line containing critical bug fixes
--3.90--
features added
* AltirraOS: The boot screen in the XL/XE version now continues boot on disk insertion rather than forcing a reboot.
* AltirraOS: Extended memory scan limit for 800 version to $D000 to support 52K expanded configurations.
* Audio: Individual channels on the secondary POKEY can now be muted.
* Cartridge: Added JRC 64K + RAM cartridge type.
* Cassette: Optimized cassette tape emulation routines.
* Cassette: Added option for high-pass prefiltering before the turbo tape decoder.
* Debugger: Improved loop detector in history view to more precisely capture loop.
* Debugger: Added @tapepos pseudovariable.
* Debugger: Specifying ? for a path argument now opens a file dialog to select the path.
* Debugger: The disassembly window now has support for showing procedure dividers, previewing called procedures, and jumping to call targets.
* Debugger: Disassembly and History views now save their disassembly settings.
* Debugger: Added option to disable automatic system symbols.
* Debugger: Alt+Shift+click on the display jumps to History at the corresponding beam position.
* Debugger: Verifier supports detecting access to non-canonical hardware addresses.
* Debugger: .caslogdata command superceded by updated CASDATA/CASDATA2 logging channels.
* Devices: XEP80 can now be switched to different controller ports.
* Disk: Added full emulation for 810 Turbo, Amdek AMDC-I/II, and Percom AT-88 disk drives.
* Disk: A warning is now displayed when attempting to insert a disk into a drive that doesn't support it (e.g. double-density disk into an 810).
* Disk: Detailed errors are displayed when a disk image write fails on the host and is remounted virtual read/write.
* Disk Explorer: Added Import File and Export File commands so that drag and drop is not needed to copy files.
* Display: Added option for frame blending in linear color space for better accuracy.
* Display: Color settings can be saved and loaded from external files.
* Display: Added new default preset for PAL.
* Display: The Hue Start slider in color settings now has the same I-Q angle definition in PAL quirks mode and works in PAL high artifacting mode.
* Firmware: Add Firmware now detects OS ROM images even if the specific image is not recognized.
* Firmware: Added detection for more MIO firmware images and support for auto-trimming padded 16K images down to 8K.
* Input: The keyboard layout editor now warns if the key mapping being added conflicts with a keyboard shortcut.
* Recorder: Added options for pixel aspect ratio and frame scaling.
* Recorder: Added support for recording to WMV and H.264 through Media Foundation on Windows 7 and later.
* SaveStates: Save state format rewritten to v2 (*.atstate2), now based on JSON within a .zip file for better accessibility and versioning.
* SaveStates: CPU state can now be saved mid-instruction.
* Simulator: Reordered frame wait and device poll timing around VBLANK to reduce input and output latency.
* UI: Added experimental dark theme support.
* UI: Added /reset command-line switch to selectively reset settings.
* UI: Audio monitor now shows modified frequencies for two-tone mode, indicators for two-tone mode and asynchronous receive mode, and better shows ultrasonic effects.
* UI: Added audio scope for viewing raw POKEY output.
* UI: Added options for controlling mouse pointer visibility.
* UI: Audio monitor positioning can now be customized.
* Video: Added PERITEL adapter and monochrome monitor emulation.
bugs fixed
* AltirraOS: Audio configuration is reset more often on tape reads to produce familiar sounds.
* AltirraOS: Disk boot can now occur after cassette boot and right cartridge non-boot.
* AltirraOS: OLDADR usage adjusted for compatibility with SDX QUICKED.SYS.
* AltirraOS: SIO transmit operations can now be interrupted by User Break.
* AltirraOS: The Display Handler now properly sets the default background color (COLOR4) to $06 when opening a GR.11 screen.
* AltirraOS: KRPDEL is now set and keyboard repeat rates are NTSC/PAL adjusted on the XL/XE/XEGS version.
* AltirraOS: Fixed an SIO issue with an out-of-spec short delay from asserting the command line to first command byte.
* AltirraOS: Fixed disk boot issues if a PBI device or cartridge init routine issued an SIO request with DAUX2 > 0 before the disk boot.
* AltirraOS: The boot screen now resets the Break key state properly after a boot is interrupted by the Break key.
* AltirraOS: Improved native mode compatibility of 816 version.
* ANTIC: RNMI (400/800 System Reset) is now always synchronized to VBI.
* Audio: Fixed stereo mixing being twice as loud as mono mixing.
* CPU: Fixed cycle timing for indexed illegal read-modify-write instructions and ARR #imm ($6B).
* CPU: Fixed extra instruction being run occasionally for a DLI delayed by WSYNC.
* CPU: 65C816 (dp,X) addressing mode now always wraps in emulation mode when accessing high byte regardless of DP.
* CPU: 65C816 (dp) addressing mode properly wraps in emulation mode with DP aligned, except for PEI (dp).
* CPU: 65C816 WDM instruction now properly fetches two bytes.
* Debugger: .dumpdsm -s option now interprets 6809 instructions.
* Debugger: Line number information is now updated properly when using cartridge bank mapping in MADS listings.
* Debugger: Disassembly window now accepts cartridge bank addresses.
* Debugger: Fixed broken option to auto-load kernel ROM symbols.
* Debugger: Reduced frequency of stale memory in the disassembly window.
* Debugger: Fixed incorrect call nesting in history window in Z80 mode.
* Debugger: Fixed some disassembly errors in 6809 mode.
* Debugger: Input byte (ib) now correctly issues read cycles with side effects in the main CPU address space.
* Devices: Fixed crash on ANTIC reading from SoundBoard hardware registers.
* Devices: 65C816 emulation fixes for Veronica.
* Disk: Fixed some illegal indexed RMW instructions taking too few cycles for 6502 coprocessors in full disk emulators.
* Disk: Full drive emulation FDC now allows Write Track commands to proceed immediately when the index signal is already active.
* Disk: Improved accuracy of RIOT interval timer.
* Disk: Corrected FDC head load and initial DRQ timings for Write Track command.
* Disk: Implemented FDC Write Track quirk for back-to-back CRC ($F7) tokens.
* Disk: Fixed some 6809 coprocessor emulation bugs.
* Disk: Corrected side 2 sector mappings for ATR8000, Percom, and XF551 full drive emulators.
* Disk: Fixed case where drive timing could be disrupted after hitting a drive coprocessor breakpoint.
* Disk: Seek sounds no longer overlap when disk access is accelerated.
* Disk: Fixed crash when ejecting disk at specific point during disk read command.
* Disk: FD1771 FDC now properly times out in two revolutions instead of five in 810 full drive mode.
* Disk: Fixed bogus FDC interrupts from Force Interrupt commands.
* Disk: Indus GT ignores ready status to match hardware.
* Disk Explorer: Fixed a filename validation bug with DOS 2 disks where duplicate files could be written if the original filename had extra characters after the extension.
* Disk Explorer: Modifying a mounted disk image now forces a disk change to flush caches on emulated full drives that do track buffering.
* Display: Fixed an issue with color profiles having the wrong color matching setting when initially established.
* Display: Fixed crash when pasting into enhanced text display in CIO mode.
* Display: Typing in enhanced text display (CIO mode) now clears the attract mode counter.
* Firmware: Fall back to next available firmware if default firmware for a type is removed.
* Input: Character mappings in custom keyboard layouts didn't work for non-ASCII extended characters.
* Input: Changes to custom keyboard layouts didn't take effect immediately.
* PerfAnalyzer: Joystick state (PIA port A) is now captured in traces.
* POKEY: Improved accuracy of two-tone mode timing at 1.79MHz.
* Recorder: Fixed SAP type R initial silence detector checking AUDFx registers instead of AUDCx registers.
* SaveStates: POKEY serial input state is now saved.
* SCSI: Fixed BSY being asserted in selection phase even for non-existent devices.
* Simulator: Improved accuracy of power-up values for POKEY and GTIA registers.
* Simulator: Display message via placeholder ROM if kernel ROM file could not be loaded.
* VBXE: Fixed a crash when toggling shared memory option.
* VBXE: Fixed double correction of display with gamma or color correction options enabled.
* VFS: Fixed zip/gz paths with non-ASCII characters not being encoded properly and getting dropped on restart.
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On their next update, this section will be refreshed.