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The Worlds Smallest Atari 8-Bit?


mytek

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Look what came in the mail today. Prototype V1 of the Atari 576NUC+.

 

PCB_front.thumb.jpg.e5f0748cd00b7c8b32577e0160d8a75a.jpg

 

PCB_back.thumb.jpg.31a9f5ffc6175a67d8e2c7b06448ff04.jpg

 

It measures 4.5" x 4.5" so not quite as small as an IBM NUC which weighs in at only 4" square, thus the reason I'm calling this a NUC+. Try as I might, I just couldn't get all of what I truly wanted in a board with a smaller footprint.

 

And although it's incredibly tiny, it has some big guy features which I'll be talking about more down the road. I will tell you this... the TK-II is the glue that ties everything together, requiring the firmware to take on several new and interesting duties. You'll probably notice that there is no cartridge port or parallel expansion port. This is an SIO centric design, one that provides the entire SIO port internally as well as externally. There will be a daughterboard that takes advantage of this, who's design will be developed by a 3rd party.

 

And I'll say from the get go, this will not be a public release other than the schematics, with the release of those still qualifying this project to be covered under a Creative Commons Attribution - ShareAlike 4.0 International license. However I'll be holding off on that documentation release until a bit later this year after the design has been fully tested. I also won't be involved in selling any of these myself, so please respect that decision by not ignoring it :) .

 

This looks like yet another interesting year for multiple Atari motherboard projects ? .

 

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1 hour ago, ClausB said:

What's the VGATE?

It’s likely the same thing as the 1088XEL/XLD VGATE feature - a PIC micocontroller that inhibits the display of the “noise” (random data) on the sides of the screen that can be visible on widescreen displays.

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That's a tightly packed board! Nice work :) I think the only way you'd get it much smaller would be to stack a second board on top, or else put some of the big through-hole chips on the bottom so they can overlap.

 

Out of interest, which schematics are you basing it on? I know of the Sobola set, but I remember someone mentioning that they contained errors, and they only seem to be available in graphical format which doesn't allow searching or zooming. If there's a vector version of the schematics available (or you release them), that would be great, otherwise making handy vectors for release as PDFs might be a nice winder project for me...

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8 minutes ago, Daedalus2097 said:

Out of interest, which schematics are you basing it on?

Michael is probably still offline today (fun with time zones! :) ), but I’m gonna go out on a limb and suggest perhaps he designed it based on his own schematics for the 1088XEL and 1088XLD projects.

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Wow, very nice! Very compact!  I see you are putting some SMD parts on the back, I had thought about that early on but wanted to keep mine with parts only on one side.. but it looks like the packages you are using on the back will be pretty low profile, so not much vertical space. :) 

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7 hours ago, foft said:

Mcctv is smaller ;) 
 

More seriously, great work!

I had to do some searching to find out what a MCC-TV even was. Yep you're right they got me beat on size. So I guess I should expand on the original claim and say Smallest Atari 8-Bit Based on Original VLSI Chips ;) .

 

5 hours ago, ClausB said:

What's the VGATE?

The VGATE chip as DrVenkman was so nice to explain, is a PIC MCU with firmware that defines it as a special video timing generator to eliminate the extreme areas of overscan that can be seen on many modern wide screen monitors. When used in conjunction with luma and chroma switching circuits, it briefly kills video output that was never meant to be seen. By doing so, it keeps what is going on during that part of the video signal from revealing artifacts produced as part of the gaming algorithm from appearing on screen. Games like Dropzone, Pole Position, Joust, and Preppie! benefit by having a VGATE chip.

 

3 hours ago, Colleton said:

This looks very interesting.  Hopefully TBA will put them up for sale eventually.

 

Nice work!

Thanks :) . If MacRorie likes what he sees, then it wouldn't surprise me in the least that this will be offered by The Brewing Academy.

 

3 hours ago, Daedalus2097 said:

That's a tightly packed board! Nice work :) I think the only way you'd get it much smaller would be to stack a second board on top, or else put some of the big through-hole chips on the bottom so they can overlap.

Thank you :) . I could have gone with a bit more SMD in the memory related circuits, but with them sharing a lot of connections to the bus and only having one side to connect to, I'm afraid that the extra number of vias would have eaten into the size reduction. Also with the MMUs requiring flashing, that would have necessitated a JTAG header or two. Also putting some of the big thru-hole chips overlapped on the back would have likely cut-off path ways for some of the traces, creating a catch 22 situation (and it would have increased vertical height).

 

There will be a stacked internal SIO related daughterboard coming ;) .

 

Quote

Out of interest, which schematics are you basing it on? I know of the Sobola set, but I remember someone mentioning that they contained errors, and they only seem to be available in graphical format which doesn't allow searching or zooming. If there's a vector version of the schematics available (or you release them), that would be great, otherwise making handy vectors for release as PDFs might be a nice winder project for me...

The schematic for this project was born out of parts of the 1088XEL and 1088XLD projects, which use a custom design. I have also incorporated ideas from a few other individuals which they will be given credit for on the schematics. As with all of my projects the schematic will be released as a multi page scalable vector based pdf.

 

3 hours ago, selgus said:

Wow, very nice! Very compact!  I see you are putting some SMD parts on the back, I had thought about that early on but wanted to keep mine with parts only on one side.. but it looks like the packages you are using on the back will be pretty low profile, so not much vertical space. :) 

Thank you, and I have also enjoyed your postings on your Atari Portable project ? .

 

I was initially toying around with SMD on the front, but decided to move it all the backside for ease of assembly, and subsequent troubleshooting if required. Most of it is SOIC based, with only two SOT-23 devices. These are all fairly large scale surface mount parts, so will be easier to hand solder. And due to their low profile, they hardly contribute at all to the vertical height of the board.

 

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1 minute ago, TXG/MNX said:

Nice whats next an replacement board for the 65/130XE system?

If I were to do that, you know it wouldn't be your grandma's XE ;) . It would have to incorporate every great upgrade, or at least provide the means to do plug 'n' play with them. However I don't think I would base it on an XE, and instead redo the 800XL which has a much more solid case and keyboard. It should also include electronic switching between PAL and NTSC modes based around Simius's latest Sophia2 board, by electrically switching between two Antics, and two primary crystals -- same as the XLD currently does with it's crystals.

 

However that will be a tale for another day (far into the future), and another topic to be started at that time. For now this thread will be about the 576NUC+.

 

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An MCC isn't really an Atari, so I think you still get to claim worlds smallest Atari. And I say that as someone who owns a MiSTer - FPGAs are great for emulation, but in the end it's emulation unless you have a to the transistor perfect replication with all the bus timings as well.

 

Also, can I say I'm so happy people with more interest and time against electrical engineering problems are available like yourself mytek, so lazy people like me can just buy a version later. It can sit right on top of my 1088XEL!

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I built one today, although I'm still missing a few components. Other than the SMD components on the back, it's a relatively easy build.

 

576NUCplus_nearly_done.JPG

 

576NUCplus_SMD.JPG

 

Now I have to get to work on the customized TK-II firmware so that I can test the board. Since there is no conventional ON/OFF switch the keyboard is going to control the power.

 

 

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15 hours ago, Gavin1968 said:

I would love to have it on my site too! It looks amazing and I think would be a fun kit to build.

I have a great working relationship with MacRorie, so I see him as a good manufacturing resource for this board in the USA. Perhaps you two can discuss the possibility of you becoming a distributor, if he's open to that.

 

For Europe, tf_hh is looking like the guy for both manufacturing and distribution over there.

 

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20 minutes ago, Tickled_Pink said:

Holy ... that's impressive work.

 

What's most impressive is how you were able to remove almost all the passive components.

Thanks :) .

 

I use SIPs and SOIC-16 resistor packages to get rid of a lot of the individual resistors that Atari seemed so fond of using (those were different times). Also my glue logic is simpler because of using SRAM instead of DRAM. And in this particular unit, I also got rid of a lot of configuration jumpers and/or switches by using the TK-II I/O to fill in for those functions. So selection of a given language/game slot in the ROM is all handled on the keyboard, as well as choosing bank select modes for the XRAM and enable/disable for the VGATE chip. I also greatly simplified both audio and video driver circuits by going with an entirely different route than what they did (their circuit was overly complicated in some regards). And lastly I have access to better chips then what was available BITD.

 

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This was my inspiration for this project.

 

I actually saw this before I even created the 1088XEL, and was even thinking of going down that path at first, but then there was so much I wanted to incorporate, that I was forced into the larger Mini-ITX footprint instead. Not that it was a bad thing to do that, and I think its popularity has proven that out.

 

Next there was the XLD version of the 1088, bigger still, but also much more tech was built-in to the design.

 

But I always yearned for a truly mini system that still would pack a punch of its own, albeit not in lieu of the miniaturization I wished to achieve.  And my other goal was to not have this one based on needing something that was a proprietary single sourced item.

 

However the Compact 5200 still has me beat, being only 3.5" x 4.25", although I had a few more chips I needed to pack in vs. what was required for a 5200 clone. I believe he kept his design pretty close to the original capabilities, whereas I added a few more bells and whistles to mine.

 

 

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21 hours ago, gnusto said:

And I say that as someone who owns a MiSTer - FPGAs are great for emulation, but in the end it's emulation unless you have a to the transistor perfect replication with all the bus timings as well.

It might be a replica, a clone, a compatible core, but certainly it is not emulation, even if not perfect ...

 

You can have exact transistor level and bus timing accuracy, if you insist, but I don't think that it matters, and certainly that doesn't make the difference between being or not emulation. What it matters, IMHO, is if externally it is possible to detect any difference with the original system or not. Do you really care if the voltage levels are 5.5v, 3.2V or 1.8V? Or if the raising edge of some signal takes 100ns or 10ns? You don't, not unless it affects something that you can really detect externally. That's why we usually use the terms "cycle perfect" or "cycle accuracy", because that's what, IMHO, really matters.

 

Of course, not every FPGA core is accurate, that is another matter.

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39 minutes ago, mytek said:

This was my inspiration for this project.

 

I actually saw this before I even created the 1088XEL, and was even thinking of going down that path at first, but then there was so much I wanted to incorporate, that I was forced into the larger Mini-ITX footprint instead. Not that it was a bad thing to do that, and I think its popularity has proven that out.

 

Next there was the XLD version of the 1088, bigger still, but also much more tech was built-in to the design.

 

But I always yearned for a truly mini system that still would pack a punch of its own, albeit not in lieu of the miniaturization I wished to achieve.  And my other goal was to not have this one based on needing something that was a proprietary single sourced item.

 

However the Compact 5200 still has me beat, being only 3.5" x 4.25", although I had a few more chips I needed to pack in vs. what was required for a 5200 clone. I believe he kept his design pretty close to the original capabilities, whereas I added a few more bells and whistles to mine.

 

wt808 actually intended to make an 8-bit computer system version too; but apparently it never happened.

 

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7 minutes ago, MrFish said:

wt808 actually intended to make an 8-bit computer system version too; but apparently it never happened.

Yeah he only posted 85 times total since joining AA in 2011, and then stopped. Although I see that he was last on here April of this year.

 

His work on the Compact 5200 was absolutely beautiful and done with great precision. By the end of that thread he had created a fantastic portable gaming system, and then disappeared. I wonder what happened?

 

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