There ARE pin adapters around, but only seen them for BUS mouse to PS2/serial/parallell PC port: http://www.ebay.com/itm//300785668391

For whowever bought this, can you let me know how the mouse tracking quality is at 1024x768 and 1280x1024 in Windows?

Did not buy that particular one, but.... testing the identical adapter I got, using the PS2-bit to PC, with a BUS mouse mind you, it tracks 'perfectly' at both resolutions 😁

Meaning, I don't see any difference to the optical USB mouse I just used there.
(granted, just whizzed around on the desktop, no games etc, but still...)

As for how the serial-bit(as was the only option in that auction) would perform, I suppose it would be no better or worse than a genuine serial mouse on the same computer.

- But, not sure what purpose this would serve, other than being able to use a BUS mouse in a computer lacking the BUS controller card.... ?

PS: for the record, the auction text is INCORRECT, this adapter does NOT make PS2 into serial, this is surely only used for 9-pin BUS mouse to serial(or whatever other interface).
Granted, I cannot see the pin-out in the picture here, but the FCC-ID is identical to mine, so...

Not a whole lot of purpose really; I was more curious if there was any tracking lag issues with this BUS-serial mouse conversion like there is with the existing PS/2-serial options. It is an ongoing question for me - Why do both the Raritan and Vetra PS/2-to-serial converters have issues with tracking quality and/or lag?

feipoa wrote:

[...]
It is an ongoing question for me - Why do both the Raritan and Vetra PS/2-to-serial converters have issues with tracking quality and/or lag?

Most probably because the chips used to do the real-time conversion are slow and noone really used more than 1024x768 back then with those adapters... A newer pic-based one (like those found in amiga/atari ps2 adapters) would do wonders...

keropi wrote:

feipoa wrote:

[...]
It is an ongoing question for me - Why do both the Raritan and Vetra PS/2-to-serial converters have issues with tracking quality and/or lag?

Most probably because the chips used to do the real-time conversion are slow and noone really used more than 1024x768 back then with those adapters... A newer pic-based one (like those found in amiga/atari ps2 adapters) would do wonders...

I found the loss due to conversion is even noticable at 640x480 in Windows with both adapters. The issues just get more obvious with increasing resolution.

The issue with the Raritan could be due to a real-time conversion considering it has an issue with start-of-motion lag. The Vetra systems unit had less of an issue with start-of-motion lag, but more with tracking continuity (a little jumpy), as if the sample rate taken was not high enough. Without designing a conversion system from scratch, I really cannot comment with any certainty why both companies have failed at this endevour. It makes me wonder if they even designed these in house, or if they contracted some hourly overseas engineer to do it at the lowest possible cost.

The Vetra systems unit was a little easier to use at the resolutions I sampled. The Raritan's start-of-motion lag will make you go mad; you are always overshooting what you are aiming for unless you move your hand really slow.

It occurs to me that the Rapsberry Pi would be perfect for this sort of application. It already takes USB and can output serial with GPIO. All that's needed is a software serial mouse emulator for Linux. I'm afraid I don't quite have the programming chops to do this, but I thought I'd throw the idea out there.

Hatta wrote:

It occurs to me that the Rapsberry Pi would be perfect for this sort of application. It already takes USB and can output serial with GPIO. All that's needed is a software serial mouse emulator for Linux. I'm afraid I don't quite have the programming chops to do this, but I thought I'd throw the idea out there.

Time + commitment!

Slightly off topic, but I wouldn't mind seeing a Gertboard and RTC built into the Rasberry Pi (as one PCB), even if it doubled the cost.

If I understand correctly you are suggesting to make the Pi act as a serial<->ps2 bridge... if you have the knowledge to do this then this project would suit much better a dedicated micro-controller like a PIC or Atmel one....

The Pi alone can't drive a PC's serial port from the GPIO pins. The protocol is right, but the voltage levels are wrong.

You'd still need a MAX3232 or similar to convert the 3.3v LVTTL signals from Pi to +/- 12V for the PC's serial port.

I have a ps/2 port that plugs into the COM1 header and it didn't work with my old ball intellipoints. Ah well.

CTMOUSE did recognize it and enabled it "in Mouse Systems mode" but it still didn't work with my mouse, and the last Mouse Systems mouse i've had was serial.

^ the mouse needs to support both serial and ps2 protocols for those simple adapters to work, it is almost certain the devices tested were ps2-only...

keropi wrote:

If I understand correctly you are suggesting to make the Pi act as a serial<->ps2 bridge... if you have the knowledge to do this then this project would suit much better a dedicated micro-controller like a PIC or Atmel one....

That's true, but it would require custom hardware. Even just an arduino + USB board would cost more than an RPi with serial board. If someone did this for the Pi, their software work would be immediately useful for anyone with a Pi. If someone did their own hardware solution, then the rest of us would have to get some custom hardware built.

Yes, the ideal solution is for someone to hack up a tiny microcontroller board that can do this. But I don't think the market exists to justify doing that, otherwise it would have been done already. It is a little absurd to imagine hooking an 800mhz/128mb computer to a 33mhz/16mb computer just to run mouse input, but this whole hobby is a little absurd to begin with. 😅

it's not really that complicated design-wise... certainly cheaper and usable from the 1st second the pc boots... have a look at the amiga_serial->ps2 converter, if someone writes the PIC program for pc_serial it will work just fine:

the project is here btw: http://aminet.net/docs/hard/mouseps2.lha
I once had a .hex for this kind of purpose , made a single adapter that worked just fine and donated it to a friend... it is lost now along with the project files 😢 the whole thing costed ~4-5eur to make 🙁

How is the PIC Microchip MPLAB IDE compared to the Arduino IDE? I think a lot of people think of the Arduino first for this type of project because of the extensive free base of libraries and online example code. I personally have found creating systems around the Arduino/Atmel to be quick to develop. My only annoyance being that newer IDE's sometimes don't work well with some older add-in libraries. This only means that if I need to alter the code sometime later, it is safest to use the old IDE.

Keropi, did you program your ps/2-to-serial PIC converter in assembly (35 instruction limit), or did you use C? I noticed that MPLAB can work with C compilers. I have the PIC1 starter kit, but have not had the time to play with it yet. I have been spoiled by the Arduino.

The Rasberry Pi + Arduino combination (Gertboard) seems like a very natural evolution to the plug computing and MCU world. For sensing applications, having a low-power SQLite database right on the Rasberry Pi with the Arduino is a dream come true. I'd really like to see an FPGA, Rasberry Pi, Arduino Mega, and RTC combine into one for the ultimate all-in-one gadget.

@feipoa :
I have no idea how the programming was made, all I got was the compiled .hex ready to burn and schematics like above.... If I could program I would make an adaptor without second thoughts 😁

OK, so you did not write the program; someone else did, but you have kept the assembly source code and the IntelHEX compiled code. The PIC16F84 used in this project is a DIP-18. My PICKIT1 starters kit can only accomodate up to a DIP-14. However, I have the PIC16F684, PIC12F683, PIC12F675, and PIC16C745 in stock at home. The PIC16F684 looks the most similiar, but the pins are configurable for different options, such as, RC3/AN7/P1C. The PIC employed in the converter design does not have configurable options, so it might require more assembly language tinkering on my part to accomodate those pin assignments.

Alternately, I have a universial programer which can program various devices like EEPROM, MCU, and PLD's. The PIC16F84 is on the programming list, so the quickest course of action for me would be to order some of those exact PIC chips. PIC16F84-10/P can go up to 10 Mhz, so if you wanted to adjust the designed oscillator from 3.4 MHz double, or triple, you can. This might be a good test if the tracking quality is too slow, but if there are pre-defined wait states put in place, increasing the frequency might not do much. We'll see...

There is another version of this PIC, the PIC16F84A, which seems to be a lot newer, cheaper, and is the "enhanced" version. Some versions of this unit can run up to 20 MHz. I couldn't really find any difference in the pinouts or anything glaringly obvious from the datasheet between the "A" and non-A versions (although I didn't look very hard).

All of these PIC's are sold on digikey, which is just one example of many online IC stores who sell them. Some are also sold on eBay from China. It might source one non-A at 10 MHz and one "A" at 20 MHz as a variation (from China).

I can program the PIC, plop it on a breadboard, along with a few resistors, caps, and a female PS/2 port, and a male DB-9. This shouldn't take more than 1 hour to whip up. I'll also need to hook up my variable supply to 5 V. I'll report back when the appropriate PIC's are in-house. I hope the standard Microsoft Serial Mouse Port drivers work.

Keropi, before you gave away your converter, did you test it in Widows/DOS? How did you program the PIC in the past? Do you have more of these PIC16F84 chips?

@feipoa
I only had the compiled .hex and nothing more... I programmed the PIC with my willem lpt programmer IIRC, have no other device for these things... I only have a couple of 18F2455 pics atm that I was using for ps3 some years back...
We only used the device in DOS I'm afraid, I have no idea if it was OK in high resolutions... 🙁 in DOS it was fine but judging from the amiga design then it will be OK as I tested the elbox adapter with resolution up to 1280x1024 and it was perfect.

I can confirm the following item works:
Cybex 4-port KVM, mpn = "520-147 C"

- Mouse:
Microsoft infrared optical USB mouse(is PS2 compatible/combo mouse) with USB->PS2 green passive adapter.
(this is the mouse I normally use on all my computers, incl the one this is typed on)

Tested on:

1.intel BX board (which HAS PS2 ports already)
a) DOS 6.20(ancient mouse.sys), DOOM2 (standard resolution):
- Works fine/as expected, mouse is recognized on COM1.
(this is an identical DOS image from the hdd of the old serial PC with socket 5 below, i.e. mouse works without changing ANY drivers!)

b) WinXP SP1, 1280x1024:
- Works just fine on desktop/explorer, no skipping or lagging

2. SiS Green socket5 motherboard - no inherent PS2(and serial on ISA cards!)

Only been able to test in the bios so far, due to massive problems getting it started, booting and whatnot.... 😖
(first seems like the AT-PSU is gone, then the HDD-controller card is busted, and the new one does not play well with the system - i.e. boot hangs mid-POST...)

- But can confirm the mouse to actually work in the windowed AMIbios menus (which has some mouse capabilty/options).

---

Disregarding all the computer issues, the only fly in the ointment so far seems to be it requires a PS2 cable(from PC) for power(OR to be actually present/connected, regardless) - i.e. when using only mouse(PS2) as 'master'/console and then 1 serial cable to/from 'slave' PC, no lights turn on when using a generic/universal AC adapter (6v/0,7a).
Only other explanation would be the (/exchangable/detachable) adapter connector tip not fitting properly, but feels like it does.

Making it somewhat harder to easily use as a standalone USB-Serial mouse 'adapter'. Still possible though.

Here is a link for the item:
http://www.ebay.co.uk/itm/370500183604

Edit: a 'glowing' and informative review:
http://www.anandtech.com/print/356

And, I would be surprised if this slightly different 2-port model(PS2 left to the VGA instead of above) did not work as well:
http://www.ebay.com/itm/370573849811
"Cybex Switchview 520-154 B"

------------------------

And while looking at his vast amount of stuff, I also found this intriguing contraption:
http://www.ebay.co.uk/itm/370507405593
"Cybex Commander AR-8 8-PORT KVM Cable Switch 520-001"

The connector for CGA/EGA/MDA in particular. 😲

Not sure what conversions apply - the connectors+cables(see links below) are a bit ambiguos.
Possible to have VGA master and DB9 CGA PC on one of the 'slaves' ?
Should be very cheap for some US-residing punters to pick up and test though (the hefty intl shipping cost really kills it for me...).

Would be very nice if it could double as a CGA to VGA converter as well... 😁 😁

Only problem would be cables, but I assume some of the ones he also sells might be the correct ones ??
http://www.ebay.co.uk/itm/320631292048
http://www.ebay.co.uk/itm/330511716072
.

would it not be more useful to make a USB to serial converter? (if that is possible)

More useful, surely! I'd buy one 😎

But.... someone(?) would have to actually make it first, and have it for sale somewhere 🤣

At least these KVMs are available right now, and some even for less than USD $2 each...(!)