TI Mini Expansion System

[Artoj]

Hi All,

While going back over a few of the ideas I have being looking at, the V9958 with HDMI on the Tangnano20k is a definite goer. So I put together the I2C and a 16 bit GPIO with the Tangnano20k and make it fit inside the case, which I have called TI-TANGO. This is only a preliminary excursion to make sure it will all fit inside. A set of ribbon cables must be used to bridge parts of the circuit, H1/H2 and H5/H8 and H4 goes to the back of the Cartridge port, the only other soldering will be the sound port pin connection. The choice of a back plane is still to be decided while the addition of 32K is also another part not done as yet.

 

The I2C uses the spare pin of the TMS9901, giving you control of the I2C port by, R12 = >0000 with TB 12, TB SBO SBZ 16, TB SBO SBZ 17, which are enough to do the job, this still needs some prototyping.(as per S Conner). You will need to reposition the TMS9901 and add a socket, while the TMS9929/18 needs to removed and a socket added as well.

 

The GPIO uses 74ls259/74ls251 to give you 16 bits of I/O by, R12 = >0400 with CRU bits 0 to 15. (as per T Nouspikel)

 

Regarding the Tangnano20k you will need to follow the thread on the Atari forum for more details (as per Retrocanda76). Regards Arto

[GDMike]

Can it run mdos? When ready 

[Artoj]

51 minutes ago, GDMike said:

Can it run mdos? When ready 

As these are purely hardware mods and does not affect the operating system, I guess mdos will work fine. At present the V9958 needs no extra software as it will run in 9929/18 mode when running on a stock system, where the I2C and the GPIO will need assembly to be usable. I hope to use a myGROMY to add calls of these interfaces to TI Basic, I have yet to add 32K/MIDI/RS232 and a PIO port. I hope to make this a add-on board for any stock TI99/4A with a myGROMY chip, this should upgade the old TI99/4A without a giant PEB. Remember the I2C will give you a gateway to SD cards, USB and SPI converter chips. Regards Arto

Edited November 5 by Artoj

[+FarmerPotato]

On 11/5/2023 at 7:11 AM, Artoj said:

As these are purely hardware mods and does not affect the operating system, I guess mdos will work fine.

GDMike is joking--MDOS is for Geneve and uses 640K+

[GDMike]

7 minutes ago, FarmerPotato said:

GDMike is joking--MDOS is for Geneve and uses 640K+

Yeah 32K ain't going to cut it

[Artoj]

7 hours ago, GDMike said:

Yeah 32K ain't going to cut it

LOL, sorry i know little about MDOS or Geneve, but still i cannot fit the 32K at present as I have added a MIDI in/out, a RS232 port and a Infrared 2 way port (as suggested by Homeautomation and his work). The prime criteria was a low profile board that does not get in the way of the GROMS and gives you a few new options for those who want connectivity. Maybe a 2MB static ram, I think there is just enough room to fit it in. Regards Arto.    

[Artoj]

Here is the latest

 

[RickyDean]

5 minutes ago, Artoj said:

Here is the latest

 

Wow a Zeno board on steriods.

[Artoj]

Here is the rough of the back plane, the IR control would be at the front of the console.

 

Edited November 7 by Artoj

[Artoj]

Hi All,

I managed to fit the 2 Meg SRAM chip (including level shifter buffers - 3.3v to 5v) with the 32k as the first bank, the use of all the RAM will depend on using part of the GPIO ports (5 bits or more?). The Cartridge extension board will be revamped with sockets to fit all the leads. I will be spending a lot of time getting the SRAM banking system working transparently. The current design is only a detailed excursion and will need lots of testing to get it to fit and work without hiccups. I will release all the schematics and designs when I have passed the prototype stage. Regards Arto.    

Edited November 21 by Artoj

[Artoj]

Hi All,

 

I separated the 32k SRAM so you can disable it, in case you already have it. The 2 MB (256k x 8 ) is now free to use in anyway that you can via bank switching or such.  I will leave at this stage, as I need to work on the DSR for the PIO/TERNARY. Regards Arto. (I have made a few error in the diagram, I will update as soon as possible,Arto)

 

 

Edited November 12 by Artoj

[Alessio Iodice]

3 hours ago, Artoj said:

Hi All,

 

I separated the 32k SRAM so you can disable it, in case you already have it. The 2 MB (256k x 8 ) is now free to use in anyway that you can via bank switching or such.  I will leave at this stage, as I need to work on the DSR for the PIO/TERNARY. Regards Arto.

 

 

Can't wait to see this project finished on Github!

That's AMAZING.

[Artoj]

Hi All,

I have fixed the errors and added the mechanical situation with the Male Header Pins on the socket, the fit is within +- 0.1mm accurate. Regards Arto.