Just a guess/question... Is the PicoGus interrupt jumper set correctly ?

If I'm not mistaken the picogus has only one interrupt line, so if it's set to, say, 7 then trying to use com2 on interrupt 3 won't work.

weedeewee wrote on 2026-07-23, 14:59:

Just a guess/question... Is the PicoGus interrupt jumper set correctly ?

If I'm not mistaken the picogus has only one interrupt line, so if it's set to, say, 7 then trying to use com2 on interrupt 3 won't work.

It is set to IRQ 3 and DMA3, and GUS mode is working perfectly.

I had to avoid the classic IRQ5 DMA1 because I already got an Audiodrive 1868F based sound card there for Sound Blaster Pro stuff . The PicoGUS has an SB16 mode, but I don't want to switch firmwares all the time, and it cannot do SB or GUS while giving me the serial mouse, which would suck in games that need a mouse and sound at the same time, like mostLucas Arts titles or Worms.

Have you disabled on board com ports from bios, so they don't conflict?

Kekkula wrote on 2026-07-24, 06:56:

Have you disabled on board com ports from bios, so they don't conflict?

Yep, both.

Legacy PS/2 support doesn't matter with PicoGUS, it uses native USB to talk to your mouse

Can you take a screenshot of the full output of pgusinit?

NeoG_ wrote on 2026-07-24, 11:45:

Legacy PS/2 support doesn't matter with PicoGUS, it uses native USB to talk to your mouse

Can you take a screenshot of the full output of pgusinit?

Sure.

The lighting is ass, it says:

Serial mouse enabled on COM2.
Mouse report rate: 60 Hz, protocol: Microsoft
Mouse sensitivity: 256 (1.00)
PicoGUS initialized!

Just running through some thoughts

• Is it a PCI motherboard? If yes have you set IRQ3 to Legacy ISA in the BIOS settings? Also disabled PnP if availalable? (By setting PnP OS installed to Yes)
• In other threads, for some reason COM2 dosn't work but COM1 does, have you tried that as a test on IRQ4?
• Do you know if your physical COM ports are working? It would be good to confirm if the issue is related to the card or the resources
• Have you tried saving the settings to flash and having the COM emulation available from cold start instead of switching after booting?

NeoG_ wrote on 2026-07-24, 23:20:

Just running through some thoughts […]
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Just running through some thoughts

• Is it a PCI motherboard? If yes have you set IRQ3 to Legacy ISA in the BIOS settings? Also disabled PnP if availalable? (By setting PnP OS installed to Yes)
• In other threads, for some reason COM2 dosn't work but COM1 does, have you tried that as a test on IRQ4?
• Do you know if your physical COM ports are working? It would be good to confirm if the issue is related to the card or the resources
• Have you tried saving the settings to flash and having the COM emulation available from cold start instead of switching after booting?

It is a ISA/PC motherboard ( https://theretroweb.com/motherboards/s/gigabyte-ga-486am ), the PicoGUS is jumpered to IRQ3 and DMA3, working just fine in GUS mode at the very least (haven't really tested other modes), but the GUS mode, which uses both DMA and IRQ, works in games and Impulse Tracker 2.14.
PnP is enabled, I am unsure whether I can turn it off because my second sound card (Terratec Gold 16/96 based on the ESS Audiodrive 1868F chipset) is PnP.

I have not tried COM1 / IRQ 4, I guess I can try jumpering the PicoGUS to IRQ4 DMA 3 and see if it still works.

I have no physical COM port devices to test the physical COM port functionality with, but a legacy DOS driver for Logitech mice does detect activity on COM2 as long as I set the PicoGUS to emulate a mouse on that port and doesn't if I don't.

Also didn't try having COM emulation work at cold boot, will try that timely.

regarding the com port assignment.. you can either try to enable onboard com1 or get the mousedriver to use com1 with irq3

as in the address that normally is com2 is seen by dos as actually being com1 due to location in bios tables... just a guess.

Jumpering the PicoGUS to use IRQ4 instead (and therefore COM1) makes the mouse work.
It also requires the Logitech mouse protocol (pgusinit /mouseproto 1), otherwise the x axis movement is completely ignored.

That being said, CTMOUSE still says "Error: Device not present" no matter which protocol, but a Logitech-specific mouse.com driver program is providing the functionality I wanted, now that I am forcing COM1 instead of COM2.
Strange, since both serial ports are disabled in the BIOS.

NorsteinB wrote on 2026-07-28, 14:16:

Jumpering the PicoGUS to use IRQ4 instead (and therefore COM1) makes the mouse work. It also requires the Logitech mouse protoco […]
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Jumpering the PicoGUS to use IRQ4 instead (and therefore COM1) makes the mouse work.
It also requires the Logitech mouse protocol (pgusinit /mouseproto 1), otherwise the x axis movement is completely ignored.

That being said, CTMOUSE still says "Error: Device not present" no matter which protocol, but a Logitech-specific mouse.com driver program is providing the functionality I wanted, now that I am forcing COM1 instead of COM2.
Strange, since both serial ports are disabled in the BIOS.

A bit strange regarding the logitech mouse driver.
The com port number, address and irq are more easily understood given their "fixed" standard addresses & irq combinations, the fact that the bios enumerates them at boot and fills a specific table with the addresses at which one is found, (which in your case would be zero since you disabled them), the fact that at first you had pgusinit set the mouse at com2, while there would be only one emulated port, which would be COM1 but with the address and irq for com2 and something along those lines of somewhere it got lost in translation.
I'd have to look at what pgusinit does to make dos see the emulated serial port. or maybe Polpo can chime in if & when he has the time from not working on the picoIDE.