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New Project for my 4A and PEB


Shift838

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If any Ti'ers have a decent VGA LCD with built it speakers and want to get them to me at a good price let me know.

 

Chris,

Since this modernization is going to be all internal, you have the perfect opportunity to simply install a

<< VGA to HDMI converter >> and then just add one of the new << cheap TV with an HDMI input >>.

 

Going the HDMI route will keep you compatible with contemporary technology for the foreseeable future.

I might also mention the larger sizes of these newer and inexpensive screens works out for ageing eyes.

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Chris,

Since this modernization is going to be all internal, you have the perfect opportunity to simply install a

<< VGA to HDMI converter >> and then just add one of the new << cheap TV with an HDMI input >>.

 

Going the HDMI route will keep you compatible with contemporary technology for the foreseeable future.

I might also mention the larger sizes of these newer and inexpensive screens works out for ageing eyes.

 

I already have an HDMI monitor that for my main TI setup and I have the VGA to HDMI converter. I was just looking for a cheap monitor for use on my work bench, but I found a guy at work that has a sony 19" he is going to give me that has both VGA and HDMI inputs!

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Small update..

 

Stereo phono jack wired in and mounted on back for PC speakers or use with VGA to HDMI adapter.

 

I have installed the Atari Joystick adapter sold by arcade shopper.

 

I went ahead and created a ribbon cable to connect from the joystick port to the Atari Joystick adapter and went ahead and connected it to a male db9 as well.

 

Instead of soldering db9 males to the atari adapter i just soldered some male headers to it so I could use a standard db9 cable with headers. I bought a couple of PC db9 serial with headers. Of course I had rewire the connectors so it would match the headers correctly.

 

So now I have both joystick 1 and 2 for the Atari adapter wired into the front of the PC case and a standard TI db9 male joystick as well. So I can use Atari or TI joysticks without having to plug the adapter in and out.

 

tomorrow hopefully I plan on getting the power to the PEB lower board wired up.

 

Have to see how's the best to snake the cables so hopefully they will be out of view or at least most of them..

 

I'll take a few pics tomorrow and upload them for people to see the progress..

Edited by Shift838
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Update...

 

  • PEB Cage Mounted
  • Power provided to PEB lower PCB
    • Black to Common Ground of ATX
    • Green to +12v of ATX
    • Yellow to -12v of ATX
    • Brown to +12v of ATX

I made custom cables for the ATX connector so I did not have splice into the connector. Now if a power supply goes out it will just be a unplug, swap and plug connectors back ito the new one.

  • USB power hooked up for back of Case
  • Power LED for PEB hooked up
  • External Case LED's wiring complete
    • not hooked up - May take swing door completely off since I cannot close it with a cartridge inserted as it would not be easy to remove a cartridge)

 

I ordered some 1.5 amp 7805 voltage regulators as recommended by Insane Multitasker to swap out on my cards before I start testing with actual cards in there. I also ordered a couple of new Electrolytic Capacitors which are 35v as recommend by Ksarul for his new SAMS card since the ones on the card are rated at 16v. He recommends to change them over to 35v for the project I am doing.

 

 

 

 

post-35187-0-63388200-1486751142_thumb.jpg

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I ordered some 1.5 amp 7805 voltage regulators as recommended by Insane Multitasker to swap out on my cards before I start testing with actual cards in there. I also ordered a couple of new Electrolytic Capacitors which are 35v as recommend by Ksarul for his new SAMS card since the ones on the card are rated at 16v. He recommends to change them over to 35v for the project I am doing.

The 1.5amp 5v regulators are a great match for the Geneve but aren't necessary for all cards. If cost is not an issue, the switching regulators are a good option as the significantly reduce heat and keep things stable. ckoba (no longer on AA) had recommended specific components last year, though some cards may not be properly designed/grounded (the older Horizon RAMdisks, for example). This year I intend to go the switching regulator route for my main system.

 

Like Ksarul, I use the 35v caps when I update and repair cards. I think Richard uses 35v and 50v caps.

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Can you elaborate on this as it pertains to HRD's ? Esp the grounding part.

Some info can be gleaned from here for the HRD+ as it relates to grounding and the circuit:

 

https://www.disavowed.jp/index.php?/archives/15-Refurbishing-a-Horizon-HRD+-RAMdisk-Card.html

 

Entry related to the HRD4000

https://www.disavowed.jp/index.php?/archives/35-Refurbishing-a-Horizon-4000-RAMdisk.html

 

Read all of the blog entries as time permits... lots of good info.

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Some info can be gleaned from here for the HRD+ as it relates to grounding and the circuit:

 

https://www.disavowed.jp/index.php?/archives/15-Refurbishing-a-Horizon-HRD+-RAMdisk-Card.html

 

Entry related to the HRD4000

https://www.disavowed.jp/index.php?/archives/35-Refurbishing-a-Horizon-4000-RAMdisk.html

 

Read all of the blog entries as time permits... lots of good info.

 

Read those blogs again Tim. Looks to me like blog 1 describes a modification to a HRD to allow a switching reg to work. Seems he had everything 55 until he put a new component in.

 

Blog 2 actually describes this change. It also neuters the 4000 by putting a 6264 at U11. Cuts capacity in half. He got it workingish but I don't think he understood the theory. The 4000 is not a ram disk but it is 2 ram disks with 2 dsr's provided there is a 62256. Understandable as it is not intuitive to have 1 physical card that has the functions of 2.

 

Unless i misread that is.

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Read those blogs again Tim. Looks to me like blog 1 describes a modification to a HRD to allow a switching reg to work. Seems he had everything 55 until he put a new component in.

 

Blog 2 actually describes this change. It also neuters the 4000 by putting a 6264 at U11. Cuts capacity in half. He got it workingish but I don't think he understood the theory. The 4000 is not a ram disk but it is 2 ram disks with 2 dsr's provided there is a 62256. Understandable as it is not intuitive to have 1 physical card that has the functions of 2.

 

Unless i misread that is.

I linked both entries for the switching regulator comments.

 

I don't know if he understood the 4000 theory. The only two 4000 cards I know of (one of them being Tony's) did not work as two RAMdisks with the jumpers set and 62256 installed.

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I linked both entries for the switching regulator comments.

 

I don't know if he understood the 4000 theory. The only two 4000 cards I know of (one of them being Tony's) did not work as two RAMdisks with the jumpers set and 62256 installed.

 

What i read is that he modified the power circuit to use a switching regulator instead of a linear one. That's fine and should be more efficient but doesn't make the original circuit incorrect as he states. Any power circuit doesn't necessarily need a system ground only a potential difference which the 2700 Ohm resistor supplies connected to the 8ish volt supply. One could make the argument that (if I read his post correctly) that using a 5v switching regulator connected to system ground and routing the output through a diode could provide marginal supply voltage due the forward loss. At any rate it works for him and that is what matters. I agree that his understanding of the 4000 may be sketchy (as may mine) but it is supposedly 2 separate ram disks to respect the 4Meg limit of ROS.... not your version ;-).I think a lot of his rants about RAM based DSR's and stacked chips don't take into consideration the historical conditions when these things were being produced. but whatever.It's sunny and about 70 degrees here. You and Beck enjoying the warm ?

Edited by marc.hull
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With this project I am realizing that the flex cable interface cable really is too long.

 

Is it possible to shorten it without causing any issues. I believe (correct me if I am wrong) but the Flex card must be in slot #1, so with my setup in this case slot one will be fairly close to the 99/4A side port with the way I have it fitting int he case. If I could shorten the cable to say 12 to 16 inches then I could strap it up and out of the way right next to the card itself.

 

Thoughts?

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Having recently looked at the schematics for the FLEX cable interfaces, it is just buffers, and buffer controls, a little bit of signal conditioning because they may be so long, but that won't hurt anything on a shorter cable. Replacing the big fire-hose with a much shorter cable should be fine. You should be able to make it as short as you want. Probably the shorter the better, particularly if you also lose the shielding. I would imagine you can get away with marrying the board in the boot to the flex card in-peb board with short wire or ribbon, and then use a boot-extender to get back to the console.

 

-M@

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I have conversed with Stuart a few times today talking to him about his cable he used for his interface to his PEB project.

 

From what I understand is that the components in the actual Fire Hose connector really are used to boost signal since the cable is so long. He believes that I could eliminate all those components and just use a ribbon cable as long as I properly map out the connections. This is because I can go super short with the cable since it all will be housed in the same box and very close proximity to the 99/4A expansion connection port.

 

This would definitely be a plus.

 

Anyone else thoughts of if this will work ?

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yup. I knew he was a guru when it came to interfacing and that's why I reached out to him. Just wanted to run it past the rest of the TI'ers as well as having it all in this one spot for reference also makes it easy to recall the information and supply it to anyone else that is wanting to do something similar.

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I have finished soldering the components onto the un-populated Flex Cable interface board I purchased.

 

Looks good I think.

 

I still need to make t he cable.

 

If you notice I used some standard 2.54mm headers to make the connector for the cable and plan on using some dupont connectors. I found out with the standard headers if I removed every other pin they fit nicely. I know I will not have to hook all 44 up, but since I may be doing some trial and error for getting the right cables mapped out to the correct pins and since I will be using dupont connectors it will be easier. I also decided to socket the LS244 and LS245 chips. New 1 amp 7805 with heatsink too.

 

I also replaced the standard LED with a set of headers so I can just plug an LED on it like a PC LED.

post-35187-0-28558900-1487297681_thumb.jpg

Edited by Shift838
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