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New Project for my 4A and PEB


Shift838

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I have finished wiring up the cable for the Flex card to the 99/4a expansion port.

 

I ordered one of the PEB extension cables from hello cables and verified it worked then I took off the male connector. Stripped the wires and mapped the pins to the wires.

 

This ribbon cable has each pair of wires twisted and has a plastic shrink wrap over the entire ribbon cable. Makes it stiffer than a regular ribbon cable.

 

Tomorrow I will make some final voltage reads on the PEB lower PCB and then see if I got it all right and the 99/4A powers up with the interface card in. If that goes well then I will replaced voltage regulators on a 32k card and try again and go into XB and see if I can see the extra RAM.

 

Report back then.

Edited by Shift838
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i have finished building the card and hooked up the cables a couple a couple at a time and the TI boots.

 

I see an issue that the LED does not flash like the flex typically does.

 

Also putting a 32k card in and going in XB and issuing a SIZE command does not return the extra ram. So this leads me to think the flex card is not working correctly.

 

Anyone have a clue of what I need to check. All my solder points look good, no bridged connections, etc.

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That's good stuff there... :)

 

I need a shorter flex cable... One that isnt an inch thick, too. :)

 

 

Here is the exact pinout's I used to make a shorter one. of course like I said my cable is only 20 inches and so far it seems to work. still doing a lot of testing though.

post-35187-0-74369700-1487555495_thumb.jpg

Edited by Shift838
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Here is the exact pinout's I used to make a shorter one. of course like I said my cable is only 20 inches and so far it seems to work. still doing a lot of testing though.

Looking good ... glad to see it's shaping up! Hopefully all the signal pins match for power on ;-]

I've been tinkering in Express PCB and finally got my first proof done for replacing my PEB cable with a 2.5" x 3.3" board that contains all the buffer electronics fed to a high-density (HD37) connector so I can go with a round 2.5' cable to my newly populated PEB cards.

post-48993-0-39489300-1487557105_thumb.jpg

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Looking good ... glad to see it's shaping up! Hopefully all the signal pins match for power on ;-]

I've been tinkering in Express PCB and finally got my first proof done for replacing my PEB cable with a 2.5" x 3.3" board that contains all the buffer electronics fed to a high-density (HD37) connector so I can go with a round 2.5' cable to my newly populated PEB cards.

 

nice. I would be interested to snag a couple of these when you release them.

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Shift838, on 24 Feb 2017 - 10:30 PM, said:

I was told today that me taking the 99/4A mainboard out of the shielding may cause RF issues.from interference. Any experience from other tiers on this? Should I keep the shielding around the mainboard and mount it that way in my ATX tower case?

 

There no top (component side) shield on the QI motherboard ...

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I was told today that me taking the 99/4A mainboard out of the shielding may cause RF issues.from interference. Any experience from other tiers on this? Should I keep the shielding around the mainboard and mount it that way in my ATX tower case?

I've routinely had both 4A and QI boards "naked" on my bench (uh, kitchen table :D ) and I have not experienced any.

Now with that said, I've also very deliberate to trim all excess leads off pins/solders produced from what I assume were mechanical assembly methods rather than careful hand assembly/soldering. Any wire the length of .1 the wavelength of a frequency will TRY to act like an antenna, emitter or receiver (this is similarly why best practices laying out PCB traces avoids 90 degree turns).

That's all the theoretical stuff I've dealt with in avionics systems aboard aircraft ... but, honestly don't see a problem here since modern PC cases do a pretty good job of acting as Faraday Cages to prevent stray emissions.

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I never had a problem either, but I was ordering a cable from IEC today and talking with a guy named Joe Miller and he said he used to work for TI and on the 99/4A project and said the whole reason they put the shielding around the 4A's was because without it it would get RF interference.

 

Thought I would check. But I thought the as you do that the PC case acts as a shield anyway.

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I think using the shielding around the 4A mainboard will mount very well in my ATX tower case. Part of my shielding on one of my mainboards is actual soldered a bit to the mainboard (on an early beige model -NOT QI).

 

I am wondering since that is like that I can mount it directly to the ATX chasis that's aluminum without having to bring it up off the chassis.

 

Anyone see any issues with doing that or should I bring it up where the shell is not touching any metal?

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Shift838, on 25 Feb 2017 - 03:25 AM, said:

I never had a problem either, but I was ordering a cable from IEC today and talking with a guy named Joe Miller and he said he used to work for TI and on the 99/4A project and said the whole reason they put the shielding around the 4A's was because without it it would get RF interference.

 

 

I would have thought it was the other way round - the shielding is there so it passed the stringent FCC tests for emissions coming *from* the TI. If you can use it and you don't get interference on your radio or TV, I don't think you'll have any problems.

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  • 2 weeks later...

So I have been discussing my options for my cartridge port issue with various people like Ralph, Insane Multitasker and Sinphaltimus. I am borrowing some of Sinphaltimus design for his 4 port cartridge port expander. Hopefully this will resolve my issues I am seeing that the FR99 does not work with anything really longer than an 8 inch extension cable. I need something a bit longer.

 

So I have decided to build a 2 port cartridge expander. This cartridge expander will stay mounted in my all in one unit and I will have a cartridge extension cable to load up other cartridges and have the FR99 and soon to be (when released) the FinalGrom99 always mounted. I will be able to select between the two with a DPDT slide switch and have a reset button too.

 

I will of course need to mount a reset button for the FR99 on the front panel. I have also tested a SD card extension cable (45cm) and it works with the FR99 with no problem. I will need to mount that as well so I can easily have access to swap out the SD cards if needed.

 

I went ahead and tested a 45cm MicroSD extension cable too successfully with the SCSI2SD adapter for my WHT SCSI card.

 

Here is a picture of what the cartridge expander will look like. I have not wired it up yet. resistors are not on the board yet. But this is just the rough layout.

post-35187-0-73067200-1489803451_thumb.jpg

Edited by Shift838
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Update on 2 port Cartridge expander.

 

I have wired up

 

1 Male port connector

1 Female Cartridge port

2 resistors

DPDT switch

Jumper set (for reset and DPDT switch connections)

 

Had a couple of issues. a wire came off one solder point and i hooked the DPDT switch up wrong. Fixed and I can now state that Sinphaltimus seems to work good. I will be testing more extensively once I get t he other cartridge port attached and wired up. So far I have tested with the FlashROM99, XB 2.7 suite (UberGROM) and standard XB cart and all seem to work fine.

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  • 2 weeks later...

Update.

 

2 port Cartridge port has been built!

 

Thanks to Tursi for loaning his brain and helping me figure out the issue with the UberGROM with it.

 

Also thanks to Sinphaltimus as I borrowed a majority of his design but condensed it down to 2 ports.

 

For anyone wanting to know how I did it I am using a 3PDT slide toggle switch to go between GROM PORT #1 & GROM PORT #2.

 

Here is a drawing of how it's wired. I only annotated the wires on the schematic that are not straigh through. All other wires to each pin on each connector are wired straight.

 

 

post-35187-0-19089300-1490842612_thumb.jpg

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I finally got my 3PDT switch and all is working as expected with the cartridge port.

 

Now I have a few things I need to do to complete this puppy.

 

  • Mount all Floppy Drives (make new cables)
  • Mount all SCSI Drives
  • Mount SCSI2SD
  • Mount SD & MicroSD extension cables
  • Mount Cartridge Select Switch
  • Mount speech

 

This is pretty much whats left. All the cards I have seem to already have a 1 amp 7805 voltage regulator. From my understanding the .5 amps are all listed to be a 78M05.

 

I am hoping by the end of this weekend I have my TI-99/4A-AIO all ready and running.

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I got a bit done today. I have

 

  • Mounted my EZ135
  • Mounted DSk1 and 2 (80 track 3.5)
    • made internal floppy cable for DSK1 and DSK2.
  • Mounted an external reset switch for the FlashRom99 since it will be permanently mounted in the case.
  • Ran a SD card extension to the FR99 and mounted on outside of case for easy access to the FR99 SD card
  • Mounted 2 BLUE LED fans in case.
  • Mounted Cartridge selector switch
  • Wired up Reset 99/4A console reset switch

I will be running a MicroSD card extension as well for my SCSI2SD.

 

I have tested the SCSI system and I have decided to go with just my EZ135 and my SCS2SD system due to space limitations in the new case.

I will also leave my 40 track 3.5 and 5.25 drives as external to the system since I do not use them that often. They will be hooked up if I need them.

 

I am using a stock Flex Cable with 1 amp upgrade since i have not figured out my flexcable interface card that I built. So I have a bit of the flex cable hanging out of the back (for now).

 

i'm hoping to have this thing buttoned up next day or so and will take some pictures and details of the final specs.

Edited by Shift838
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Photo?

 

Here is what I got done today.

 

I have the SCSI system completely installed, custom cables made and traced.

 

SCS1= EZ135

SCS2 = 250mb HD

SCS3,SCS4,SCS5,SCS6 = 250mb partitions for each drive on a SCSI2SD adapter with MicroSD.

 

SD and MicroSD extension cables.

 

Few more things to do, but here is a photo of what I have done so far (front of case) and one with what the lights look like in the dark.

post-35187-0-98780500-1491877837_thumb.jpg

post-35187-0-15655000-1491877844_thumb.jpg

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Here is what I got done today.

 

I have the SCSI system completely installed, custom cables made and traced.

 

SCS1= EZ135

SCS2 = 250mb HD

SCS3,SCS4,SCS5,SCS6 = 250mb partitions for each drive on a SCSI2SD adapter with MicroSD.

 

SD and MicroSD extension cables.

 

Few more things to do, but here is a photo of what I have done so far (front of case) and one with what the lights look like in the dark.

 

OMG! That is freaking awesome and such great workmanship. Wow.

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