Jump to content

Photo

TIPI - TI-99/4A to Raspberry PI interface development


84 replies to this topic

#76 aftyde OFFLINE  

aftyde

    Chopper Commander

  • 212 posts

Posted Wed Jul 5, 2017 3:06 AM

Love the idea of a PEB board that could quite literally replace every other card...    Being able to fire up a 80 col F18A term program to talk with the PI would also be cool... running MUTT for email on my TI would be satisfying!  ;)



#77 ElectricLab OFFLINE  

ElectricLab

    Chopper Commander

  • 192 posts
  • Location:Hillsboro, Oregon

Posted Tue Jul 11, 2017 4:54 PM

Hey look, a TIPI thread!

 

I've been so incredibly busy with work during the past couple of months, and haven't been keeping up with the forums here. I'll have to do something about that :)



#78 ElectricLab OFFLINE  

ElectricLab

    Chopper Commander

  • 192 posts
  • Location:Hillsboro, Oregon

Posted Tue Jul 11, 2017 5:00 PM

"TIPI", I like what's happening here, looking forward to it. Will this work with a raspberry Pi 3, and could the code be ported to a beaglebone? Thinking out loud, don't know anything about them, but do have two Beaglebones, white and black. I am going to experiment in a few months and see if I can go in the same direction. Cool things going on in the TI community ;-)

 

Yes, it should be able to be done with a Beaglebone. In retrospect, we should have used a Beaglebone since they're TI :)
Since Matt has reduced the pin count for the interface to the TI, TIPI should work fine with the older PIs as well. 



#79 --- Ω --- OFFLINE  

--- Ω ---

    --- Ω ---

  • 10,195 posts
  • TI-99/4A Fanatic
  • Location:In the den playing with my FinalGROM 99!

Posted Wed Jul 12, 2017 8:48 AM

I can see a future with hundreds of new and newly returned TI-99/4A users world-wide.  Many of them will be running configurations with a TIPI or 32K sidecar paired with an F18A and a FinalGROM 99.  

 

The future's so bright, I gotta wear shades. - Timbuk 3 (used out of context)



#80 Shift838 OFFLINE  

Shift838

    Stargunner

  • 1,881 posts
  • SHIFT838
  • Location:Texas

Posted Wed Jul 12, 2017 2:05 PM

Love the idea of a PEB board that could quite literally replace every other card...    Being able to fire up a 80 col F18A term program to talk with the PI would also be cool... running MUTT for email on my TI would be satisfying!   ;)

 

Yes this would be fairly easy to do.  'tcpser' to the rescue on the Pi.  you could connect a RS232 card to a USB to Serial adapter to the pi.

 

Of course not sure if the TiPi is using all the GPIO pins of the pi.  If not there could be room to expand there as there are serial lines on the GPIO connector for the Pis.  If I recall it's pins 6, 8 and 10.  I would really need to test to see if this would work, but it should.

 

I currently run it this way with my MiST machine and use tcpser via the GPIO.  I use tcpser with the TI99 on the pi as well via a USB to serial cable then to the TI rs232.  I can get up to 38400 with TIMXT accurately this way.

 

So plenty of options I'm thinking..



#81 jedimatt42 OFFLINE  

jedimatt42

    Stargunner

  • Topic Starter
  • 1,157 posts
  • Location:Beaverton, OR

Posted Wed Jul 12, 2017 3:47 PM

I'd rather just write new TCP clients on the 4A and skip tcpser and baud rates and just let the PI do the buffering.

But for legacy serial based programs, what Shift838 suggests should work great, provided you have a legacy RS232 card.

As for GPIO pin usage.. I have moved to the lower pins on the GPIO header of the Raspberry PI. So that snap on I2C solutions are easy to use, and most of the pins are available for imaginative hackery.

I need at a minimum 7 GPIO + ground. But I'm using the 2x5 section at the end, which brings out an extra GPIO and doubles up the ground connection...

-M@

#82 jedimatt42 OFFLINE  

jedimatt42

    Stargunner

  • Topic Starter
  • 1,157 posts
  • Location:Beaverton, OR

Posted Thu Jul 13, 2017 1:33 AM

 

Yes, it should be able to be done with a Beaglebone. In retrospect, we should have used a Beaglebone since they're TI :)
Since Matt has reduced the pin count for the interface to the TI, TIPI should work fine with the older PIs as well. 

 

One of the design goals ElectricLab and I both realized and implemented was the need for the communication protocol to work no matter how slow or bogged down the RPi gets. Since you'll likely to turn the RPi into a network file server, or be managing from the web server on board. 

 

Also the software side has the IO highly isolated so I would expect it is easy to port to an alternative platform with GPIO and python. 

 

----

 

Updated routing and layout has occurred to fit the form factor of the 32k sideport RAM card.  Just needs some time to bake in the back of my head, and I need to remap my verilog to the CPLD and check viable pin assignments... :)  Routing is the ultimate puzzle.  I'm sure I forgot something, or will pretty a few things up.  But at least it passes the design rule check. And the parts fit on the paper layout test. 

 

https://github.com/j...cad/pcboard.pdf

 

 

-M@



#83 Sinphaltimus OFFLINE  

Sinphaltimus

    Stargunner

  • 1,790 posts
  • Distracted at the Keyboard
  • Location:Poconos, PA

Posted Thu Jul 13, 2017 7:39 AM

Just curious about the Pi setup. I'm going to order a Pi3 for RetroPi use. Could the same Pi be used with your TiPi implementation and still have RetroPi on it? Wondering if a Pi purchase for TiPi means a dedicated Pi or not.



#84 --- Ω --- OFFLINE  

--- Ω ---

    --- Ω ---

  • 10,195 posts
  • TI-99/4A Fanatic
  • Location:In the den playing with my FinalGROM 99!

Posted Thu Jul 13, 2017 7:42 AM

One thing I've been wondering about the TIPI project, since it's based on a Raspberry Pi, are addons going to be referred to as A la Mode?



#85 jedimatt42 OFFLINE  

jedimatt42

    Stargunner

  • Topic Starter
  • 1,157 posts
  • Location:Beaverton, OR

Posted Thu Jul 13, 2017 8:30 AM

Sinphaltimus:

The RPi should not have to be dedicated. I have features in the code that backs off when not servicing requests from the TI.

Omega:

No. :)

-M@




1 user(s) are browsing this forum

0 members, 1 guests, 0 anonymous users