New features/fixes

General:

• New bus timing, fixes compatibility with IBM PC/AT 5170.
• Faster IOCHRDY timing to improve compatibility and spend less time on ISA bus.
• Less aggressive overclock and different startup timing to improve stability on reset.
• Added support for Xbox 360 wireless adapter dongle.

A new release of the more DIY friendly version of PicoGUS "backporting" improvements from the v2.0 board.

• Adds option for integrated DAC section. The purple "GY PCM5102" DAC modules have spotty QA, so integrating the DAC is both potentially lower cost and more reliable. Footprints remain to still allow use of the DAC module.
• Reset stability improvements: RC circuit on Pico RUN pin to delay start on power up and filter out glitches on ISA reset, and U5 is now 74AHC logic family for higher positive-going threshold
• ISA RESET has weak pulldown to allow reliable programming the Pico outside of powered PC
• DACK has weak pullup to allow PicoGUS to be used without DMA channel set
• 5V MIDI circuit: uses open drain inverter for better drive and uses more commonly available resistors
• U2 is now specified as an 74LVC244 in the BOM: it's cheaper and more available and in my testing performs just as well as the 74CB3T3245
• Jumper to apply power to micro USB-B connector on Pico to allow USB HID devices to be used
• Fixes to card dimensions to better follow ISA card specs: narrower card edge and better fit for card bracket in PC cases
• Production files for JLCPCB full PCB assembly
• Updates to thank you section on back

As always immediately after I do a big release, a significant bugfix comes soon after! Don't forget to look at the notes for firmware v1.0.0.

General:

• Increase stability upon startup on PicoGUS 2.0 boards.

The PicoGUS 2.0 hardware brings v1.0.0 of the PicoGUS firmware! This firmware runs on all released revisions of the PicoGUS hardware: 1.1, 1.1.1, 1.2, and 2.0.

New features/fixes

General:

• Support for PicoGUS 2.0 hardware and its software-controlled wavetable header volume (/v xxx pgusinit option).
• A preview of game port joystick emulation using USB joysticks is included in all sound card emulation modes, enabled with the /j pgusinit option. There is also a "joystick exclusive" firmware (pg-joyex.uf2) for when you only want to use a USB joystick and not emluate any sound cards. This is considered a preview because only a few USB joystick types are supported: wired Xbox 360 (and third party clone) controllers and the Sony DualShock 4. More joysticks will be supported in the future! See the Compatibility List wiki page for more information about this feature.
• Much more reliable firmware flashing from DOS. The previous method abused IOCHRDY to hold the ISA bus far longer than usual, and some chipsets would release the bus before certain flash operations were complete.
• A more robust startup sequence to improve firmware boot stability. All firmwares have the same LED sequence when starting so you will know when the firmware is ready.
• Compatibility with slower PSRAM chips that are rated for only 104MHz, such as the Vilsion Tech VTI7064MSME and ISSI IS66WVS1M8BLL-104NLI. This widens available options for those DIYing their own PicoGUS boards.

pgusinit

pgusinit has been updated to version v2.0.0, featuring:

• Updates to pgusinit to support the new firmware flashing protocol, as well as support upgrading from v0.x.x firmware to v1.x.x firmware. If you have a v0.x.x version of firmware running on your PicoGUS, you can upgrade to v1.0.0 with the latest version of pgusinit included with the firmware release package.
• Detects the current card mode and only shows options applicable to that mode when using /? to ask for help.

Adlib emulation:

• Fixes an issue where some software would incorrectly detect PicoGUS as an OPL3 instead of an OPL2.

MPU-401 emulation:

• Sysex delay can be enabled with the /s pgusinit option. This will prevent buffer overflows on older MPU-401 revisions.
• Fake all-notes-off for the Roland RA-50 can be enabled with the /n pgusinit option.
• Fixes song change issue in Frederik Pohl's Gateway. PicoGUS will detect when Gateway is running and enable a hack in how the version and ack are returned. Run pgusinit to restore default operation after you're done playing Gateway.
• Running pgusinit will silence any stuck notes if a program exits unceremoniously.

Note: Please use the version of pgusinit.exe that comes with this firmware!

Version v0.7.0 of the firmware has a much smaller default GUS audio buffer size of 4 samples, thanks to the higher RP2040 clock speed. If you run an older version of pgusinit.exe, it will set the buffer size to 16 samples, negating many of the improvements that this version brings for GUS emulation.

Release notes:

General:

• Runs the RP2040 at 400MHz. This allows for faster reaction to ISA events, holding IOCHRDY low for shorter time periods. This allows better performance for other ISA cards and may help run on faster ISA bus speeds.
• Fixes from @SuperIlu for pgusinit to fix usage message and improve command line parsing.

GUS emulation:

• Higher clock speed enables much shorter interval before checking for IRQs. This should improve compatibility in titles that use IRQs and DMA.
• Fixes for Hand386 and other M6117D-based systems.
• Changes to pgusinit to default to the new GUS buffer size of 4 samples, and support setting the buffer size below 8 samples. Please use the new version of pgusinit that ships with this firmware!

Tandy emulation:

• New emulation core contributed by Aaron Giles. This is the same core used in DREAMM and should result in better accuracy across all titles. or example, sound effects such as crickets chirping and meteor crash in Maniac Mansion and snoring in Zak McKracken sound much better.

CMS emulation:

• New emulation core contributed by Aaron Giles. This is the same core used in DREAMM and should result in better accuracy across all titles.
• Fixes issue with pitch of CMS sound being too high.

MPU-401 emulation:

• Misc optimizations might improve compatibility in some titles.

For known issues, please see the Compatibility List wiki page.

Another bugfix release! This release fixes a bug introduced in firmware v0.5.0 that caused Descent to freeze on the Loading... indicator when running setup and starting the game.

GUS emulation:

• Fixes freeze when starting Descent. This patch release uses a smaller/simpler 4-byte DMA buffer that solves the freeze with Descent while also hopefully still preventing stuttering in Doom introduced by level changes (the reason for the DMA buffer in the first place).

For known issues, please see the Compatibility List wiki page.

CMS emulation:

• New emulation mode: CMS/Game Blaster.

For known issues, please see the Compatibility List wiki page.

Bugfix release! All of the new features of v0.5.0 plus the following fixes:

Tandy emulation:

• Fixed reporting of base port when running pgusinit when on Tandy firmware
• Fixed firmware flashing from DOS when on Tandy firmware

General:

• More reliable firmware flashing from pgusinit by clocking down the Pico and disabling interrupts. Many thanks to JazeFox at Vogons for debugging this issue and suggesting a fix.

Tandy emulation:

• New emulation mode: Tandy 3-Voice. This emulation is on port 2C0h by default, to avoid conflicts or masked IO on the default Tandy port of 0C0h in non-Tandy systems. This is the same alternate port that Matze79's "TNDY" card can use. Use the TNDY driver program to redirect port 0C0h to 2C0h. Also many games need to be patched to allow for Tandy sound on non-Tandy systems with CGA, EGA, or VGA graphics. Note that this mode has not received much optimization, so accuracy and compatibility can be improved.

GUS emulation:

• Resets DMA status bit to 0 on completion of DMA handler. Fixes some Demoscene titles.
• Buffers uploaded DMA samples instead of writing 1 byte at a time. Currently this buffer is 8 bytes, and may be configurable in future releases. Should help stuttering/slowdown issues in games that use streaming DMA audio like Doom.
• Bails out on sound rendering when sample rate changes. This should eliminate any "warbling" sounds when Impulse Tracker resets the channel count on the fly.
• Uses the RP2040 hardware interpolation unit to interpolate samples and clamp output to 16 bits.

For known issues, please see the Compatibility List wiki page.

General:

• New version (v1.0.1) of pgusinit.exe - DMA interval is in µs, not ms

GUS emulation:

• Refactored DMA transfer completion handler: this results in much higher compatibility with titles that use streaming DMA. Overriding the DMA transfer interval is not necessary in most circumstances now.
  • Fixes games: Quake, Doom (and Doom engine games), Duke3D, Descent, Hocus Pocus (partially); Demo: Inside
• Fixed bug where DMA control register was not properly reset between transfers. Fixes garbage samples when uploading mixed 16 & 8 bit samples.
  • Fixes music players/trackers: Open Cubic Player (with gusFastUpload=on), Fast Tracker 2