JVS IO to RS485 input on ripoff X2 build

    • All TypeX/X2 games will I/O error if you do not have the actual JVS controller hooked up to a JVS device. Since the rs232 to rs485 adapter isn't an actual JCS controller, it doesn't matter whether it can take JVS input or not, the games won't boot without some form of external modification.

      Part of this process I'm trying to figure out is what the point of it all is for X2 games specifically. I can use it just fine with other JVS software for input translation but not the games natively. That's probably no big deal in the long run, but it's a roundabout way of going at it. Either way, being able to accept JVS input is great, opens the door for using things like MAME or other PC games thru JVS :)
    • I use the JVS PAC for mame because the default key map is set up for it. The reason I was hoping to skip it for X2 is because the default kepmap includes alt and space which will crash the game when pressed at the same time. Using a non standard keymap fixes this, but to enable that I have to leave the jumper on that allows other combinations of buttons to perform extra functions. I prefer not to have that jumper on. Minor inconvenience but an inconvenience nonetheless.
    • Bump.

      Does anyone know what the Taito I/O card actually does?
      Looks to me that it is just an off the shelf part and not something specific to the JVS standard..



      The part number is G4S306-IO, which is referenced in the user manual for the DFI G4S306-C motherboard which looks to be the model used for the Taito Type X...
      Is this the same I/O as used with the TTX2?



      There are several references to a 'card-edge connector (optional)' in the manual that include 'Game port', 'S/PDIF' & 'Serial' connections.



      I assume the 10 pin connector opposite the USB port is the serial connection.
      I can't tell from looking at the PCB what conversion is occurring, but as this is just off the shelf... is it simply a serial to USB conversion?

      Com2 --> USB --> JVS I/O

      (Yes, i am aware that the JVS 'USB' port isn't following USB protocol, but perhaps it is just a relay to the serial interface...?)

      I am interested in native JVS support on a non native TTX2 setup
      Perhaps a suitable substitute for the Taito I/O card could be found that would manage this task?

      Could someone with an actual TTX2 check their I/O card to see:

      1. If it is the same as the card above,
      2. What the two chips on the USB side of the card are?

      Cheers!
    • that JVS board is a bridge between rs232 standard serial found on most computers to rs 485 the serial protocol used for JVS. the only simiarity JVS has with USB is the port it uses. it is in no way similar in any layer of its communication and can cause damage to either device if plugged in to usb.

      the board also acts as the first IO board in the chain and sends the dip setting to the game via the JVS protocol.

      as for the 2 chips on the board one is a RS485 to TTL converter the other is a microcontroller that takes in the TTL and spits out rs232 aswell as handle the dips and acts the the first JVS.

      a very similar board is used in a TTX2 and they should be compatible with each other although i have not tested this yet. i will once a TTX+ arrives from japan in the coming weeks.

      edit:
      the JVS board takes power from the Front panel header as well as activates the reset switch when it doesn't sense any JVS traffic across it
      it also pass a reset switch to the pci bracket and HDD and power status LEDs
      Cab: Sega Blast City
      Hardware: TTX2, TTX3, Sega Ringedge and Steel Chronicles
    • corey wrote:

      as for the 2 chips on the board one is a RS485 to TTL converter the other is a microcontroller that takes in the TTL and spits out rs232 aswell as handle the dips and acts the the first JVS.
      has the binary for that Atmel chip been dumped? I'm curious how difficult it would be to build a clone of this PCB... at least for the dips/JVS port
      "Information wants to be free"
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    • skate323k137 wrote:

      I came across this gallery that shows someone wiring a JVS serial interface to a rs485 adapter and using it directly. Has anyone here done the same?

      imgur.com/a/grdqU
      Haha, you found my ancient "omg how to bootleg TGM3" guide from when I knew next to nothing about JVS apart from the fact that it used RS485 as its transport protocol and the first RS232 to RS485 adapter that I bought happened to work with Type-X games by pure chance (I've tried the same with several PCI/PCI-e RS485 cards, but the initial handshake / control code translation causes the game to reject the connection).

      Good luck with replicating the I/O card! Someone once told me it's "basically the reference circuit for the MAX232 and MAX485 chips, easy to implement for anyone who remotely knows what they're doing", or something along those lines.
    • if compatibility is dependent on the adapter I managed to find that exact adapter on amazon: amazon.com/niceeshop-RS232-Com…ywords=rs232%2Brs485&th=1
      "Information wants to be free"
      VOOT | RFM | Kraylix V3 | FiF Jr. | KI2 | UMK3 | E29 | E29| TOTD | DDR
      Follow my projects on Instagram: instagram.com/twistedchu

      Buy my 3D Printed Parts: bit-district.com
    • twistedsymphony wrote:

      if compatibility is dependent on the adapter I managed to find that exact adapter on amazon: amazon.com/niceeshop-RS232-Com…ywords=rs232%2Brs485&th=1
      Picked one up from eshop.sintech.cn

      Stupid question time... Motherboard -> RS232 -> MAX232 -> MAX485 -> RS485 -> JVS I/O ? :rolleyes:

      MAX232 Datasheet wrote:

      The MAX232 device is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5V, and can accept ±30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels.

      MAX485 Datasheet wrote:

      The MAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 are low-power transceivers for RS-485 and RS-422 communication.
      Related:

    • Modern mobo's don't always have a rs232 port anymore. So, why not use an ftdi usb serial adapter instead? The outputs of such can be 5V or 3V3 so that you can interface directly with the MAX485 rs485 driver.

      This still leaves the issue that the Taito JVS adapter is a JVS device itself. The microcontroller on the board also responds to the JVS protocol and the adapter appears as JVS adapter 0.

      This brings us to the method used to enumerate JVS adapters. They use an extra signal line that can be pulled to GND by the adapter. It can be 5V, 2.5V or 0V. Such line does not exist on the RS485 protocol.

      You could emulate the JVS adapter 0 in software, or you could use an arduino connected to the pc as Comport. The chinese clones hardly cost more than an ftdi serial adapter.