99/4A Cartridge Port Issues

[Shift838]

I noticed that I have a TI console that seems to work with pretty much all the cartridges I have, but.... It does not see the FlashRom99 like my other ones do nor the XB 2.7 suite, Super Extended basic etc.

 

It is hooked up to a PEB with 32k, FDC, etc..

 

What should I check. I have cleaned the cartridge port, but since TI XB, EA, Invaders, and various others work I think there maybe another issue somewhere.

 

It does have the F18A installed as well.

 

I have also noticed that if I insert a cartridge in the port while the 99/4a is powered on then it does not do the typical reset.

 

I have even plugged the cartridges directly into the 99/4a mainboard without the L connector with the same issue.

Edited February 20, 2017 by Shift838

[+arcadeshopper]

curious what is the version on the title screen.. and date

 

Greg

[Shift838]

If you mean the 99/4a TItle screen it just says 1981 like all of mine do. The F18A has been updated to 1.8

[Shift838]

i'm wondering if I have a power supply issue with the PEB. As I noticed even on the console that is working that it just does not always see it. especially if i wait a few seconds after powering up the PEB (this one) and then powering up the 99/4a it will not see them. But I noticed if I power up the PEB and within a second hit the 99/4a power it sees it.

 

Odd.

[Shift838]

i don't think it's the power supply as it is still doing it even after being replaced. I am leaning to the console being an issue.

[+Ksarul]

Double-check to make sure your main circuit card isn't a QI board with 1981 GROMs on it. The pin out to the cartridge board is different on those motherboards. . .a couple of pins aren't fed through.

[Shift838]

Double-check to make sure your main circuit card isn't a QI board with 1981 GROMs on it. The pin out to the cartridge board is different on those motherboards. . .a couple of pins aren't fed through.

 

i don't believe it is a QI model as from what I recall all QI models 9900 processors would mounted vertical and this one is horizontal on the board.

[+jedimatt42]

Late to the party... I don't believe you can connect a cartridge directly to the mainboard, any cartridge, and expect it to work.

 

--

 

I recently had to replace the mainboard in my TI, because the cartridge port had gotten worn out. I suspect physical breaks in the ROM side of motherboard. I had gone in and re-soldered the connections and it seemed good for a week. But then began to fail again. XB2.7 would typically be seen, but crash. FlashROM99's were invisible, as were any modern ROM only cartridge. The reset mechanism worked though. TI mixed cartridges would always be seen, but crash often.

 

These are old things.

 

--

 

I suppose, you could try and sever the +5v on the cartridge port, and measure the current through there with a multimeter. That might show if the cartridges are not getting the required current. You'd probably have to go check the datasheets for the array of chips on a couple of those board designs to get an idea how much current they require.

 

-M@

[Shift838]

Late to the party... I don't believe you can connect a cartridge directly to the mainboard, any cartridge, and expect it to work.

 

--

 

I recently had to replace the mainboard in my TI, because the cartridge port had gotten worn out. I suspect physical breaks in the ROM side of motherboard. I had gone in and re-soldered the connections and it seemed good for a week. But then began to fail again. XB2.7 would typically be seen, but crash. FlashROM99's were invisible, as were any modern ROM only cartridge. The reset mechanism worked though. TI mixed cartridges would always be seen, but crash often.

 

These are old things.

 

--

 

I suppose, you could try and sever the +5v on the cartridge port, and measure the current through there with a multimeter. That might show if the cartridges are not getting the required current. You'd probably have to go check the datasheets for the array of chips on a couple of those board designs to get an idea how much current they require.

 

-M@

 

i have plugged in multiple cartridges directly in the port on the mainboard with no issues. Ti invaders, Logo fun and some others. had to take them out of their shells to do it. Just the ones I mentioned that seem to have an issue. Still at a loss of what it could be.

[+jedimatt42]

I have plugged in multiple cartridges directly in the port on the mainboard with no issues.

I just don't understand how that is possible.

 

The L-adapter does this:

 

Top  --+
       |
Bottom---+
       | |
 Front | | Back

If you connect the cartridge in straight down it ends up trying to do this:

 

  Bottom | | Top
         | | 
   Front | | Back

Anyway... you might find a clue going after the easier thing to simulate. The insertion reset behavior.

Looking at a GROM only board, it seems to involve the -5 volts, the RESET pin and a capacitor to ground. You said the insertion reset behavior isn't working either, so it may be one of those 3 pins.

I imagine for the ROM only boards or mixed, the RESET behavior only involves the RESET and GND.

 

-M@

[Shift838]

I just don't understand how that is possible.

 

The L-adapter does this:

 

Top  --+
       |
Bottom---+
       | |
 Front | | Back

If you connect the cartridge in straight down it ends up trying to do this:

 

  Bottom | | Top
         | | 
   Front | | Back

Anyway... you might find a clue going after the easier thing to simulate. The insertion reset behavior.

Looking at a GROM only board, it seems to involve the -5 volts, the RESET pin and a capacitor to ground. You said the insertion reset behavior isn't working either, so it may be one of those 3 pins.

I imagine for the ROM only boards or mixed, the RESET behavior only involves the RESET and GND.

 

-M@

 

 

Matt,

 

I think it's an issue with my homemade extension cable for the cartridge now. After your post it got me thinking.

 

I did decided to plug the L connector back on the board (i received a few extras --- thanks Tursi!)

 

I plugged the XB 2.7 directly into that and BAM that works.

 

I noticed I was having the same issue with my all in one 99/4a / PEB project so I plugged the L back in and plugged the XB2.7 cartridge in and it worked.

 

If everyone recalls I actually mounted my L connector upside down as I thought with my continuity test it would work if the right pins were connected to the cable. I reversed it and the XB 2.7 works on the all in one PEB now.

 

But the Flashrom is still a no go, well partially. It does see it now, but when select the FlashRom99 it will either hang at the menu before it displays any programs or it will see TIMXT and just show all of it as a every program.

 

I'll ping ralph on that one to see if he has any suggestions. It may be because my cartridge port extension I made is actually 14 to 16 inches and maybe it's loosing signal because of the length. I know the FR99 is good as It works in my other console with no issue. (no extension cable on that one).

 

At least I know it's not my console now!

[Shift838]

i have shortened the extension cable all the way down to 8 inches. XB 2.7 does work at 13 inches with no problem. But the Flashrom99 cartridge even with an 8 inch cable it seems to go to the menu and you get the wait circle at the bottom right, but it never gets past that.

[Stuart]

i have shortened the extension cable all the way down to 8 inches. XB 2.7 does work at 13 inches with no problem. But the Flashrom99 cartridge even with an 8 inch cable it seems to go to the menu and you get the wait circle at the bottom right, but it never gets past that.

 

Might be worth trying to add some separate, thicker power and ground cables to supplement the connections you've already got through the ribbon cable. Should be easy enough to remove again if they make no difference.

[Shift838]

 

Might be worth trying to add some separate, thicker power and ground cables to supplement the connections you've already got through the ribbon cable. Should be easy enough to remove again if they make no difference.

 

so are you saying a seperage 5v and ground line then to the cable? I think it's pin 19 for 5v and pin 2 for ground..

[Stuart]

Shift838, on 23 Feb 2017 - 1:19 PM, said:

 

so are you saying a seperage 5v and ground line then to the cable? I think it's pin 19 for 5v and pin 2 for ground..

 

Yep. If you go from handy +5V and 0V points on the motherboard to the pins on the connector on the end of your ribbon cable, which plugs into the cartridge. Might make no different at all but probably worth a go.

[Shift838]

i'll give that a shot. the power supply I am using for the 4A is quite a bit better than the original.

 

I have an extra 5v line and ground coming from there.

[Shift838]

adding the +5v and ground to the cartridge port did not help for the FR99. Same issue.