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(Hardware) Project of the 'calendar quarter'


Omega-TI

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Would anyone be interested in clear stickers for their modified "Internal 32K " consoles?

This is just an idea, I'm not setup to print them, but as time allows I could make up a few different sizes and fonts to get a 'final product'... if someone else is willing to print them off for everyone who wants one.

 

 

post-35324-0-51379000-1449261991_thumb.png

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I also need to make 1-2 internal 32K ones to use only with the 2048K Games I module ("game console")

 

PS. does someone know if the nanoPeb gets connected to an internal 32K if it will break things? (2x 32K ?)

(I cannot remember I used to have an internal 32K and later on a PEB box with 32K, but believe it cannot work together)

 

 

or does it makes sense to have something externally connected to the TI with more memory (I think I read somewhere 512K, etc.)

No clue how to use it or it will benefit. I wish I can make dedicated time to understand the internals of the TI (Craig Miller videos are

good, but quality of the video is a bit difficult to see, I also need to go through Tursi one, that explained it very well with the XB27 module

and (G)ROMS)

Edited by globeron
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You'll either need SPDT or a pull-up resistor, since you can't simply "cut off" any of the lines, they need to be attached to something. With an SPDT you put the chip side in the middle, one side to the original signal, and the other side to +5V or Ground as appropriate for the signal.

 

With my mod, I guess you have lots of options, but I'd probably disable it with a switch on the RAM's Chip Enable line (pin 20). One side to the AND gate as per the docs and one to +5v (optionally through a small resistor, 1k or so). When the switch is placed in the 5v selection, the chip enable is permanently high and the RAM chip will never respond. Flicking the switch while the system is running may cause a crash (less likely if not using the 32k at the time, but it is always possible).

 

With a pull-up resistor you can use an SPST switch on the same line -- the pull up resistor goes from CE to any +5V source, and the switch is inline with the wire to the AND gate. I don't like it quite as much because the system has to override the resistor to activate the chip, and the console kind of has a lot of that going on already. You'd probably want to try a 10k resistor here, though.

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:) Nice project wire, it's almost impossible to make a mistake with this stuff.gallery_35324_1027_15211.jpg

 

Just take your time and prep your wires ahead of time with a little flux & solder. To attach them, just touch it to the correct pin on the chip, that's also treated with a "smidge of flux" and it'll take as soon as you apply the heat of the soldering iron. It only takes a second.

 

If for some reason you manage to make a mistake, no big deal, it's easily correctable!

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  • 2 weeks later...

I'm going to do the 32K mod this way, there will be a few extra wires to solder, but i don't need to worry about the pin-bending, snipping, etc. Also each pin is simply soldered to whatever the label says, so no head-scratching. I will add a simple paper overlay to lay on top of the 9900 so that pin-counting is not an issue as well.

 

(Don't use this until I have tested I have "proofread" it by building one!) If it's OK I will put it on Osh Park so that you can just order on-line. I don't think Osh (Orchard Supply Hardware?) claims ownership for public projects, nor shares any profit, so someone might feel free to also sell populated boards with Kynar wires preattached. Since the Amazon order I made for the chips were not "prime", in fact they are probably slow-boating from China, I won't be able to test this for a few days or weeks.

 

Ti prelim

Edited by towmater
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If you like, let me know how it goes and I can send the Gerbers off to the place I use to do boards (and I can whip a board up in a flash for something as simple as this one is if you need files in unrestricted Gerber format). That may be a lot less than doing them through Osh Park (probably no more than $3-$5 per board, depending on the board footprint), although Osh is great for doing test runs to validate a design.

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I can post the brd file if you want. I wish OSH didn't make you order three. The reason to do it this way will be the simplified installation, IMHO, even if it is a rather simple board. Although I'm paying for two layers here, I kept the bridge on top so that one can make a self-etched, single-sided version from the same layout.

 

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