The Worlds Smallest Atari 8-Bit?

[+mytek]

That turned out beautifully and will be great asset to the NUC project, really completing it ?

 

 

Either FujiNet stand-alone, or a simple plug-in upgrade to also have a cartridge port ?

 

A little background info: Both the NUC's Antic and MMU get piggybacked with the actual chips transferring to the top of this new FujiNet daughter board design. This provides the bulk of the signals required for the cartridge port, with one other signal (/CCTL) coming from a 2-pin header on the NUC.

 

Mr Robot and I went round and round about the need for a cartridge port, but in the end I had to concede that it was a good idea. His execution of it is absolutely superb, allowing for one to either have it or not, while still being based on a common daughter board. Sometimes you've got to be willing to accept someone else's plan, and now that I have, I'm happy that I did. This new board is 100% Mr Robot's mechanical design, in both the PCB and the custom case that will house it all. The electrical circuit of the FujiNet aspect matches up with the last experimental prototype V1.5 design, with a significant addition by Mr Robot (I'll let @Mr Robot spill the beans on that one).

 

Full post and pics...

 

[Simply_Graham]

Oh dear looks like my head will be on the block ... especially using Metric ..  Just remember the note about the plastic case at the edge connecter end having a different over hang from other cartridges.  If it would help, I'm happy to send a cartridge over to you @Mr Robot

@mytek & @Mr Robot Just like to congratulate you on turning out something so cute and 'nice'

??

[Mr Robot]

This project has always been about getting this to be as compact in design as possible, hence the title of the thread. If you don't need a cart port, this NUC+FN+Cart board fits into the non-cart case making the whole thing 47mm high, just as the FN only board did. With the cart port added we have had to inevitably increase the height to allow for all the extra cart port plastic, it's now 70mm high if you need a cart port. 

 

 

[Mr Robot]

8 minutes ago, Simply_Graham said:

Oh dear looks like my head will be on the block ... especially using Metric ..  Just remember the note about the plastic case at the edge connecter end having a different over hang from other cartridges.  If it would help, I'm happy to send a cartridge over to you @Mr Robot

@mytek & @Mr Robot Just like to congratulate you on turning out something so cute and 'nice'

??

Thanks very much! The cart socket itself is copied from the moulding in my 800XL so it should handle everything that plugs in just lke the original. I have made it wide enough to fit the AVGcart which uses the same size case as the SIDE 2, SIDE B and other homebrew carts recently, I've added space for the 3.68mm block on the cart you measured for me and that has provided enough room to get fingers under when removing carts. I think we are pretty good to go and I was only joking about holding you responsible. 

 

If I need to take you up on your kind offer I will let you know; thanks!

 

[Simply_Graham]

@Mr Robot your most welcome, it's a shame that I live the wrong side of the pond, otherwise I'd love to be a little more involved, however my coding skills are not up to Jon's (FJC)as a for instance; however I do make my own additions to Atari's on the Hardware side. I've followed @mytek for some while and built both of his previous big projects the XEL & XLD. my preference is for a build from scratch bar the Mother board. I for some reason have always preferred Hardware, however I'm getting better at coding, as at some point I have to test the hardware I design although not items as complex as Simius or Candle have produced. 

[+ZuluGula]

On 9/25/2020 at 6:52 PM, mytek said:

And for the first time ever, I went with a yellow solder mask and black silk screen.

Could you please tell me, where you can order a yellow solder mask and black silk screen pcb?

[+mytek]

On 4/1/2021 at 10:32 AM, ZuluGula said:

Could you please tell me, where you can order a yellow solder mask and black silk screen pcb?

ALLPCB

[ivop]

This part looks dangerous:

 

The voltage divider can go as high as 9.9V, which is beyond the 8V maximum GTIA can tollerate. Or am I missing something?

 

[+mytek]

4 hours ago, ivop said:

This part looks dangerous:

 

The voltage divider can go as high as 9.9V, which is beyond the 8V maximum GTIA can tollerate. Or am I missing something?

 

Well considering that the original charge pump circuit can do close to 9V, that already exceeds the presumed 8V maximum. But keep in mind that both the stock Atari circuit and this one are severely current limited, this one with the series resistors. Maximum current available is 2 ma which shouldn't exceed the current handling of the GTIA's input clamping diodes. Of course if you have the pot set to the extreme end to produce that amount of current, you will also have some very strange colors . The circuit as shown produces pretty close to the correct color with the trim pot at its mid position, so that's where the pot should be initially set.

 

BTW, the LM4040AIZ-10.0 limits the available voltage to 10V prior to the 4.7K series resistor.

 

[ivop]

3 minutes ago, mytek said:

BTW, the LM4040AIZ-10.0 limits the available voltage to 10V prior to the 4.7K series resistor.

Yes, I was aware of the Zener diode. Hence I calculated ~9.9V relative to 10V.

 

So the charge pump is out of spec, too

 

It seems that GTIA can handle 20-25% overvoltage on CADJ, at least at a low current. Or as you say, nobody leaves it at that, because you will have some strange colors.

 

But what if the pot fails while you are not looking, and CADJ is constantly overvoltaged for a long time? Would that be bad?

 

[+mytek]

27 minutes ago, ivop said:

Yes, I was aware of the Zener diode. Hence I calculated ~9.9V relative to 10V.

 

So the charge pump is out of spec, too

 

It seems that GTIA can handle 20-25% overvoltage on CADJ, at least at a low current. Or as you say, nobody leaves it at that, because you will have some strange colors.

 

But what if the pot fails while you are not looking, and CADJ is constantly overvoltaged for a long time? Would that be bad?

 

2 ma at 2V over spec isn't going to hurt anything as far as I'm aware.

 

I think I know why you are so interested in this circuit .

 

EDIT: if you are still feeling uneasy, simply up the series resistor from 4.7K to 10K or more, it should still work.

 

[ivop]

3 hours ago, mytek said:

I think I know why you are so interested in this circuit .

I think you think right

 

If space permits, I might implement both this circuit and the original charge pump, and switch with a jumper, to leave the option open to use +5V only.

[+mytek]

I wrote a blog post about finally getting a case around my 576NUC+ with the FujiNet daughter board inside.

 

Really looks tiny compared to big brother XEGS

 

 

Blog Post:  576NUC+ Modded Proto Case for FujiNet

This is how its done when you don't have an updated STL design ready to print

[+CharlieChaplin]

But the 576NUC+ case is missing the pastel buttons ?

[+mytek]

1 minute ago, CharlieChaplin said:

But the 576NUC+ case is missing the pastel buttons ?

I was thinking the same thing after I took the picture. Maybe some pastel model paint is needed to spruce up the currently black buttons .

[Mr Robot]

Progress pic of the cartridge port lid

[Mr Robot]

OK I think all the cases are finished. There may be some tiny adjustments to the holes for the fujinet board if my measuring was off at all.

What do you think? Should the back panel be silver to look like metal or color coded to the rest of the case?

 

The eagle eyed among you might notice the volume dial on the back there, that adjusts the volume of the SIO audio in. At the moment that means you can adjust the volume of the SAM speech, but at some point in the future it will allow you to adjust the volume of cassette audio and any other audio things the Fujinet team have planned for SIO audio!

 

[mdivancic]

Nice work Mr. Robot.

[Redherring32]

On 3/6/2021 at 9:34 AM, mytek said:

Don't worry I'm not into self inflicted pain, and this would definitely match that category. However I do have a lot of respect for anyone that can pull that off while achieving a production look to the finished product.

 

Heh, that's precisely how I would describe the experience of doing it, but I'd do it again. 

If you can shrink down your design as much as you want without cutting chips, then definitely avoid it.

 

Thanks for the kind words by the way :)

[Dinadan67]

This is one if the coolest projects of all time. I ordered mine today at the Brewing Academy and looking forward to it! ? 

[Mr Robot]

If you want a different case than the default one, custom cases are available from me here. 

 

https://therobotfactory.net/shop/3d-prints/576nuc-case/

 

[+MrFish]

14 minutes ago, Mr Robot said:

If you want a different case than the default one, custom cases are available from me here. 

 

https://therobotfactory.net/shop/3d-prints/576nuc-case/

 

That's a reasonable price, $20.

 

[+MacRorie]

59 minutes ago, MrFish said:

 

That's a reasonable price, $20.

 

Glad you think so because it is the price of the default one as well!

 

BTW, this is as good of time as any to announce that the 576NUC+ is available for sale!!  Yeah!  Woo!  

 

MyTek's Atari 576NUC+ Computer

 

*I* would like to think that it is a VERY reasonable price all around.  Also, if you want to purchase it a little bit at a time, then you are welcome to do so!  The PAL version includes the ColorBurst daughterboard for PAL color.  We expect that these will take about 2-3 business days to build until we get a good supply of them pre-built, so expect your order to take about 5 business days from order date to ship date.  We plan on being faster than that, but wanted to under-promise just in case.

 

We also have a lot of other new products available for sale:

 

Want a 3.5" floppy drive?  Well, we are now selling what we are calling the "Atari 1035"!  Developed by DropCheck and I, this features all new parts (well, except for the 1050 case) and works very nicely with SpartaDOS X and SpartaDOS 3.2.  It will work with other Atari DOSes, but your mileage may vary.

 

Atari 1035 by The Brewing Academy

 

Also, if you have an Atari with an Ultimate 1M already installed AND you want to have access to Mass storage WITHOUT occupying your cartridge slot OR modifying your case, we now have the PBI2CF3 and ECI2CF3 CompactFlash hard drive interfaces:

 

PBI2CF3: Put a CompactFlash HDD interface on you 800XL or 600XL (you will need to add two wires inside of your 800XL and one wire inside of your 600XL. VERY EASY)

 

ECI2CF3: Put a CompactFlash HDD interface on any Atari computer with an ECI (130XE, some 65XE, and some 800XE) No modifications needed, plug & Play

 

We also have Vectrex cartridges, CEDs, Amiga & Commodore products, and MORE MORE MOREEEEEEEE!

 

{ahem} done now.

[+MrFish]

1 hour ago, MacRorie said:

Glad you think so because it is the price of the default one as well!

 

BTW, this is as good of time as any to announce that the 576NUC+ is available for sale!!  Yeah!  Woo!  

 

MyTek's Atari 576NUC+ Computer

 

*I* would like to think that it is a VERY reasonable price all around.  Also, if you want to purchase it a little bit at a time, then you are welcome to do so!  The PAL version includes the ColorBurst daughterboard for PAL color.  We expect that these will take about 2-3 business days to build until we get a good supply of them pre-built, so expect your order to take about 5 business days from order date to ship date.  We plan on being faster than that, but wanted to under-promise just in case.

 

Yeah, quite reasonable for an assembled and tested machine. I guess that's one of the benefits of miniaturization.

 

Is there a full list/diagram of what all the available ports are?

 

Also, will there be a separate model available with the cartridge port?

 

[+DrVenkman]

2 minutes ago, MrFish said:

Is there a full list/diagram of what all the available ports are?

 

Two joystick ports, standard Atari 5-pin DIN for audio/video, PS/2 keyboard connector, DB15 SIO port with optional DB15-Atari SIO adapter, power input (12VDC, IIRC, but it's been a minute since I built my Beta unit and can't remember for sure). If you go with the integrated FujiNet, there's also a slot for the FujiNet's integrated SD card.