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mozzwald

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Everything posted by mozzwald

  1. I've designed a custom carrier board for the nodemcu with a new take on the SIO connector. OSHPark boards have shipped and should arrive this week. The new SIO connector uses round DSUB pins that solder directly to the PCB which slides part way into a 3D printed connector. This should make it smaller and easier to build (no need to cut, strip, crimp wires for SIO). Here's a test I did with an old SIO23V3 pcb: In the mean time I've been working on a case to put it all in: Below you can see how the pins sit on the carrier board: Lots of empty space in the bottom since the nodemcu sits on top and carrier board is dead center. Clips hold the two halves together, buttons for reset and flash, cut out for microusb: In the earlier stages of the case design I had posted some pictures on twitter. Someone had asked about making it a pass through device with SIO in and out. I think this could be done using the same technique but using male DSUB pins. The issue with adding it to this board would be placement of the nodemcu and having the microusb port accessible. If you rotate the nodemcu 90 degrees it would interfere with a neighboring SIO port if plugged into a device (like a disk drive). Or, it could have two ports with pins and you just use a cable to connect it.
  2. I briefly thought about this, but I don't want it to interfere with a neighboring SIO port. Will need to measure. If plugged into the back of your 1050 drive it should allow the neighboring SIO connector to also be used. Ultimately, my goal is to have something plug and play for stock or minimally modified Atari systems. If you can build Mytek's 1088XEL/XLD then I assume you can figure out how you want it connected internally 😉
  3. I have 2 questions/concerns about the nodemcu modem if anyone could comment.. 1. Is there any issues with using the SIO 5V to power the modem? I know the 1200XL has a current limit resistor. The other systems afaik are spec-ed at 50mA load on 5V. I have not run any tests to check current draw of the Nodemcu board, but my limited use so far on an 800XL has shown no problems. Having the MicroUSB accessible when plugged in to SIO could make this a non-issue on systems where the Atari 5V is unreliable for the modem. I have an Atari 400 I can test with. 2. The MicroUSB port and Wifi antenna are on opposite sides of the Nodemcu board. To me, it makes sense to put the USB on the side away from the SIO connector but then the antenna is close to the system and would have traces underneath it on the carrier board. Do you think this could cause issues with either wifi signal strength or data transmission on the SIO lines?
  4. There's a pull down resistor under the nodemcu, no capacitor. The nodemcu already has a 10uf capacitor on it's input
  5. Nice. This is what I made for Thom to use as a test rig. He should be getting it this week.
  6. Nevermind what I said earlier, it looks good
  7. Should be possible in software. Really, all we need is the command line and read the command. If it's not for the modem, ignore it. Could probably make it work exactly/similarly to an 850. I think motor ctrl is a good temporary solution, not needed ultimately. New R: handler is probably the best route as Thom suggests
  8. Looked at the thru hole schematic and I think you have the mtr ctrl and cmd lines swapped like in my first wiring diagram. I'll hafta verify again with my actual hardware again when I get home. As long as the esp8266 can see what is happening on the motor control and command lines, it can decide when to write or read the datain/dataout pins. So, if the esp8266 is supposed to be D1 and it reads a command for D2, it can ignore it. Likewise, it can respond to a D1 command. It's just a matter of making the code do that. Atarigeezer's hardware version which uses motor control to physically disconnect the tx/rx lines will not work like this.
  9. The 8 channel one I have is 14mmx28mm, 2.54mm spacing. Rows are roughly 10.25mm spacing (uses up 5 rows on a breadboard)
  10. Here is my fixed and updated wiring diagram. I tried shifting some of the SIO lines to different GPIO's but had problems with the Nodemcu booting. This setup boots every time. Note, you must disconnect it from SIO to use the USB for programming (with interrupt/proceed connected). I could not get it to boot into programming mode when connected to SIO (Atari on or off). Some of the flash chip pins are shared with GPIO's and are likely being pulled down preventing programming mode. I don't really know if the Interrupt or Proceed lines work without pull up/down resistors, they are currently always high. Is there a way to toggle those from BASIC for testing? Is this a good plan: use the Nodemcu board as-is and create a carrier board with the level shifting and SIO connections? Basically have a plug in SIO Modem dongle.
  11. I can't check for sure til later when I get home. If you have the esp8266 board defs installed, its one of them. Iirc, it does have nodemcu in the name, likely the latest version number.
  12. I'm currently experimenting with the gpio's on the nodemcu (esp12e/f) to include connection with the proceed and interrupt SIO lines. I think those are what someone was going to use for a new Rhandler. It's a bit tricky picking the gpios to use as some are used for bootloader / flashing.
  13. True, and I did think about this after the fact. It should be possible to move the command/motor control code out of the flow control options.
  14. Oops, yeah, I have the CMD and MTR lines wrong the wiring diagram, sorry about that. You should probably use a level shifter, but to each his own. You may burn out the esp. The swap for TX/RX is to prevent the esp boot msgs from being sent to the Atari at power up. I thought it could interfere with boot. Keep this in mind if you have any issues booting with it connected. If you could try doing a file transfer and report your results it would be much appreciated. I can do small files ~15k or less but anything larger never starts and just times out using Bob Term. And yesterday I tested it with Platoterm at 1200 baud which worked great.
  15. The fix is up. https://github.com/mozzwald/Zimodem/tree/atari
  16. I found the problem. DTR code was causing the connection to break during disk activity. Removing that seems to be working. I sent and received a small txt file with xmodem. I will clean up the code and push changes to github tomorrow.
  17. The problem is that when connected to a bbs, any SIO activity causes the connection to die and the modem is put back in AT command mode. There is a noticeable delay when the system tries to read from floppy. Then, I assume the connection is lost and the system reads from the disk just fine. In AT command mode, SIO activity is working fine.
  18. I don't have access to the files area so I installed mystic bbs on a linux box at home. I am unable to send or receive files. When connected to a server, the disk access causes the connection to be dropped and the modem is put back in command mode. Looks like more work to be done in Zimodem code 🥴
  19. Just a few more notes about the setup... You can flash the nodemcu with the usb port as normal. When Zimodem starts up, it switches the TX & RX lines from the default GPIO 1 & 3 to GPIO 15 & 13. This prevents the bootloader messages from being spewed out to the atari at powerup. This also means, you will not see anything on a serial terminal on the computer when connected with the usb port (also the command & motor lines would need to be pulled low for transmission to occur). The 1k resistor on GPIO 15 is required to prevent the nodemcu bootloader from trying to boot from SD card at powerup. The pull down on Atari side Motor Control was needed as the level shifter wasn't pulled down enough to register a low reading. Can anyone recommend a bbs that has files available for download with Xmodem? I want to see if it will work with bobterm.
  20. Definitely not using i2c on the nodemcu. Not really sure what was causing the problem. I got garbage on both the atari and pc when testing with a usb to uart adapter. Also tried 2 different boards to make sure it wasn't a bad one.
  21. I tried a similar level shifter and it didn't work (TXS0108) so I got the fet based one instead.
  22. I've been fiddling around with my nodemcu (esp8266) board, Zimodem firmware and the atari and have been successful with using the modem while allowing the atari to still use the sio bus with minimal parts. I have a simple fet based level shifter (wiring diagram below, amazon part) that adds the motor control and command lines to nodemcu inputs. When either line is asserted, the Zimodem firmware allows other devices to communicate on the bus and ignores the transmission. The modified firmware adds a new Flow Control type (FCT_AMTRCTL) which must be enabled for it to work. If you wish to flash the firmware to a previously used zimodem/esp board you should format the SPIFFS before flashing so that the new flow control will be selected by default, otherwise you will have issues with it not communicating as it will be set for some other flow control scheme (this issue bit me a couple times during testing). The modified Zimodem (v3.5) firmware is in my github (atari branch) at https://github.com/mozzwald/Zimodem/tree/atari
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