Support of Microsoft Serial Mouse on /dev/ttyS1

[toncho11]

Hi,

Is it possible to add Microsoft Serial Mouse on /dev/ttyS1 ?
I am trying to use mouse in ELKS.

[copy]

v86 emulates a PS2 mouse, which seems to be supported by elks. I wouldn't mind supporting serial mouse too, but it's probably not very widely used.

[toncho11]

No. This documentation is completely outdated.
There is experimental support for PS2 mouse on a serial line, not the bios PS2. But this is not the case in copy.sh, right?
So either Microsoft serial mouse or PS2 mouse on a serial line will be welcomed.

[toncho11]

And why in https://copy.sh/v86/?profile=elks it does say Mouse: No on the right. It should provide PS2 mouse, right?

[SuperMaxusa]

But this is not the case in copy.sh, right?

Do you mean that ELKS supports PS/2 protocol via serial port?

it does say Mouse: No on the right. It should provide PS2 mouse, right?

Yes, it reacts to PS/2 mouse initialization.

v86/src/browser/main.js

Lines 2233 to 2237 in 2996c08

	emulator.add_listener("mouse-enable", function(is_enabled)
	{
	os_uses_mouse = is_enabled;
	$("info_mouse_enabled").textContent = is_enabled ? "Yes" : "No";
	});

[toncho11]

Yes, PS/2 protocol via serial port (not through the BIOS INT 33h).

[copy]

I wouldn't mind supporting this, but it's not a high priority.

[ghaerr]

Hi @copy and @SuperMaxusa,

Do you mean that ELKS supports PS/2 protocol via serial port?

Yes. When ELKS is setup for PS/2 mouse, it executes the following code when reading from a serial port:

/*
 * Input routine for PS/2 mouse.
 * Returns nonzero when a new mouse state has been completed.
 */
static int
ParsePS2(int byte)
{
    switch (state) {
        case IDLE:
            if (byte & PS2_CTRL_BYTE) {
                buttons = byte & (PS2_LEFT_BUTTON|PS2_RIGHT_BUTTON);
                state = XSET;
            }
            break;

        case XSET:
            if(byte > 127)
                byte -= 256;
            xd = byte;
            state = YSET;
            break;

        case YSET:
            if(byte > 127)
                byte -= 256;
            yd = -byte;
            state = IDLE;
            return 1;
    }
    return 0;
}

In other words, it parses each byte of the 3-byte PS/2 mouse message read from serial. It could easily be upgraded to the 4-byte version for mice with scroll wheels or five buttons. It doesn't write anything to the mouse.

I wouldn't mind supporting this, but it's not a high priority.

That would be fantastic, thank you! Let me know if need any help from my end.

I recently ported Microwindows to ELKS, and everything is now running, multiple applications drawing in multiple windows, all running 16-bits, see the screenshot below. @toncho11 has tested this with copy/v86 and all is also running except the mouse. At this time, the ELKS kernel doesn't know anything about mice and implementing a hardware PS/2 mouse requires trapping IRQ 12 which isn't allowed for application programs... the Microwindows server performs all the mouse reading/decoding, all from serial on ELKS (and Linux). I would like to add hardware PS/2 mouse support to the ELKS kernel but its a bit complicated and requires more changes that it should. QEMU and 86Box allow serial mouse emulation but we really like how easily copy/v86 boots and runs an OS right from the web.

16-bit ELKS running Nano-X on QEMU

Thank you!

[SuperMaxusa]

Hello @ghaerr, nice to see you! Awesome work, looks really cool!

Let me know if need any help from my end.

I have experimented with ELKS and the serial port and I have a question: is it possible to change a default mouse port for ELKS (mouse utility) and Nano-X?

I tried to export MOUSE_PORT=/dev/ttys1 (on QEMU and v86) but it still uses ttys0 instead of ttys1. My ELKS version is v0.8.1.

In copy.sh/v86, COM0 is used by the terminal by default, so it would be better to use a different COM port.

Thanks!

[ghaerr]

Hello @SuperMaxusa,

Thanks, it's been fun getting Nano-X back running 16-bit.

Yes, it's possible to change /bin/nano-X and /bin/mouse to use the second serial port as you mention using export MOUSE_PORT=/dev/ttyS1 (note the capital S not s). However, you should probably be running ELKS v0.9.0-dev, as there have been some changes made recently in this area. I've attached a ready-to-go 32M bootable ELKS image for you, with the mouse port set to /dev/ttyS1 in /etc/profile. (Login as root, then type "nxstart" to start nano-X).

In copy.sh/v86, COM0 is used by the terminal by default, so it would be better to use a different COM port.

Great, I prefer it that way myself, as in that configuration debug or informative messages will be displayed on /dev/ttyS0 which is routed to the host terminal session, while the mouse operates on /dev/ttyS1. With QEMU, there is otherwise no way to get debug messages to the terminal if the mouse is on /dev/ttyS0.

Internally, there is an ELKS hack that sets QEMU=1 at boot (for qemu only) when it is programmatically found that QEMU is running, and then the mouse port is set to /dev/ttyS1 automatically (unless overridden by MOUSE_PORT=). This aids in getting users running without having to otherwise separately specify MOUSE_PORT=/dev/ttyS1. For copy/v86, we'd just upload an image that has MOUSE_PORT= set and everything should run. I've done that on the attached HD32 image.

hd32-minix.img.zip

Thank you!