1088XEL Alternative Mother-Board Project

[Matej]

This is amazing project! I will take 2x. Mini-ITX is good idea!

[+mytek]

The cartridge port is simply a 30-pin card edge connector.

 

These appear to be similar to the type used in the 600XL/800XL, I'm not cetain about PCB thisckness though.

There should also be a provision to open the bottom door on the original brown Atari cartridges. This could be done by using the plastic piece used in the 600XL/800XL, or some other method.

 

http://www.mouser.com/ProductDetail/TE-Connectivity/5530843-2/?qs=U4pz39agNJAEyt9grmD5ww%3d%3d

 

Thanks for the links. The Mouser part is very affordable. I previously ordered some of these from Digi-Key (different brand), but at twice that price.

 

This is amazing project! I will take 2x. Mini-ITX is good idea!

 

Thanks Please keep in mind that this is starting out life as a DIY project, so unless someone later chooses to produce these, there will be no purchasing available. However it is my intention to publish all aspects of the project into the public domain, so if you are handy with a soldering iron you could always roll your own.

 

- Michael

Edited January 23, 2017 by mytekcontrols

[+SoulBuster]

Is there a reason you use PS2 ports for keyboard and mouse instead of USB?

 

I would think there are more USB devices than PS2 devices.

 

If there were 4 USB, you could hook up the keyboard, the mouse and some storage.

[+mytek]

Is there a reason you use PS2 ports for keyboard and mouse instead of USB?

 

I would think there are more USB devices than PS2 devices.

 

If there were 4 USB, you could hook up the keyboard, the mouse and some storage.

 

The reason is quite simple, I don't have a USB solution that works for either of those options, but I do have PS2 ones that do. And although USB is the current standard, there are still a multitude of PS2 devices both used and NOS (new old stock) available, so the need to change is a very low priority. Of course the question of why not use USB can be taken even further, and the logical conclusion would be why not use a modern computer which comes with USB already, run an emulator, and there you go But I'm just poking fun, so don't take me serious on that one However back to your question, if I had a USB solution I would use it, but as far as I know there isn't one at this time. So implementing one for both the keyboard and mouse would take time and development effort.

 

BTW, just having USB doesn't magically mean you also get all that you are used to seeing on a PC or MAC, such as Flash Drive and Printer support. Those things require drivers of which none currently exist for the A8. So in the grand scheme, to do all of the things suggested would take a considerable development effort.

 

- Michael

Edited January 23, 2017 by mytekcontrols

[+Firedawg]

I believe a PS/2 to USB Female Adapter should work fine for those with USB mouse and keyboards. I have used them on older Mobos with PS/2 ports with no troubles.

 

Mike

[+mytek]

I believe a PS/2 to USB Female Adapter should work fine for those with USB mouse and keyboards. I have used them on older Mobos with PS/2 ports with no troubles.

 

Mike

 

Those are passive adapters that unfortunately only work with older USB keyboards and mice. The PS2 code got eliminated in newer firmware iterations, so for instance it won't work with any 2.4 Ghz wireless USB device that I know of.

 

- Michael

Edited January 23, 2017 by mytekcontrols

[+mytek]

Of course if general purpose multi-port USB support is really needed, there is always the PBI solution. Which would be to create a PBI card with 4 or more USB ports and the drivers built-in to take advantage of them (including a D: handler for USB stick memory and a P: handler for USB printer support). Still quite a project in itself, but it would be a cool one to see implemented!

 

- Michael

[+MrFish]

Actually, something akin to what you're talking about has already been done in cart form -- albeit only incorporating a single port in its implementation:

 

AtariMax: USB Cartridge

 

The links on that page for the MicroUSB Project itself are dead though; you have to go to Carsten's Wiki for the information:

 

AtariWiki: MicroUSB

Edited January 23, 2017 by MrFish

[+mytek]

Actually, something akin to what you're talking about has already been done in cart form -- albeit only incorporating a single port in its implementation:

 

AtariMax: USB Cartridge

 

The links on that page for the MicroUSB Project itself are dead though; you have to go to Carsten's Wiki for the information:

 

AtariWiki: MicroUSB

 

Hi MrFish

 

Yeah I remember seeing that, but as you say it is limited to only one port, and it takes up the cartridge slot which would be kind of a no-no for some people. Be much better to create an independent PBI Device as I described earlier. Although for the time being it probably is the only USB option available on an A8.

 

- Michael

[+MrFish]

Yeah I remember seeing that, but as you say it is limited to only one port, and it takes up the cartridge slot which would be kind of a no-no for some people. Be much better to create an independent PBI Device as I described earlier. Although for the time being it probably is the only USB option available on an A8.

 

Yes, I agree, but I thought the information might be of use if you were to attempt something, since there are already existing drivers for keyboard, mouse, etc.

Edited January 23, 2017 by MrFish

[hitchcock4]

 

Hi Kavik

 

I just started to play around with the layout, and although it's still far, far from complete (only been working on it for about a day now), it might give you a basic idea of where I'm heading.

 

 

Off to the right side can be seen all of the IC chips that will eventually need to reside on this board. And inside the board footprint I have shown a U1MB being treated as a plug-in module (will require vertical headers in place of the right angle ones it normally comes with). So basically anyplace inside the U1MB footprint that isn't occupied by a header, is fair game for other components that don't stick up very high, such as an IC chip. This is how I'll be able to fit all of the required components within the Mini-ITX Form factor, while still allowing for 3rd party upgrades such as the U1MB, UAV, Rapidus, VBXE, and Sophia. And other upgrades that I have design rights to such as TK-II-Stereo, MOUSETARI, and V-Gate will be integrated into the board.

 

The EUI (Enhanced Upgrade Interface) simply breaks out signals required by some of those 3rd party upgrades.

 

I'm also toying around with the idea of providing up to two internal PBI ports for low profile PBI Devices such as perhaps an IDE card or some other useful piece of hardware that can benefit from a parallel interface.

 

And yes there will be a cartridge port as well, but I haven't made the component for it yet.

 

- Michael

Regarding the layout -- and this is just a suggestion, as I've never created a complex PCB myself.

Since you are using the mini-ITX we can assume that anyone using the board will put it into an ITX case of their choice.

 

The size of the External PBI and SIO cause the problem that they take up most of the space along the back of the PCB. [Those not familiar with mini-ITX should know that where Michael has put the PBI and SIO are the back and would always be accessible on a ITX case.

 

So. . . that means that the 2 joystick ports and the PS2 ports would not be accessible unless you open up the case. It seems to me that one should put the ports that would get the most plugging and unplugging action at the back (always accessible). And in my opinion, the joystick ports would get a lot of the plugging and unplugging action (removed when not in use).

 

Whereas the SIO port would have something constantly plugged in. [Legacy floppy drive or printer.] Or at least one could always have the floppy drive connected and route the cable out the front or the side of the case (may require modifying the case).

 

One final comment/ question: could you stack the 2 joystick ports? And stack the 2 PS2 ports? similar to the image in this link? I realize it would be harder to do but would give you more space to work with along the edges of the board.

https://www.google.com/imgres?imgurl=http%3A%2F%2Ftechreport.com%2Fr.x%2Fam3-chipsets%2F790fx-ports.jpg&imgrefurl=http%3A%2F%2Ftechreport.com%2Freview%2F17061%2Fhigh-end-socket-am3-chipsets-under-the-microscope%2F2&docid=MPSfMSOw_0RyMM&tbnid=DOlHlAEJOH1zCM%3A&vet=1&w=600&h=255&bih=662&biw=1366&q=stacked%20ps2%20ports&ved=0ahUKEwjnu82rzNnRAhVl0oMKHdDDDNsQMwhEKB4wHg&iact=mrc&uact=8

[hitchcock4]

Also. . .

If you find that all the chips won't fit on Mini-ITX, then Flex ATX is the next size up.

Size is 229mm x 191mm

And a lot of the cases that fit an ITX will also house a Flex ATX case (but not all obviously!)

 

Best of luck with the project.

[+kheller2]

Thoughts of putting the IO ports on a PCI slot bracket? Actually, you could move some components around and have the standard required things out the back side, like PBI, PS2, Video, toss the SIO and joysticks on a bracket. Just a thought...

[+mytek]

Regarding the layout -- and this is just a suggestion, as I've never created a complex PCB myself.

Since you are using the mini-ITX we can assume that anyone using the board will put it into an ITX case of their choice.

 

The size of the External PBI and SIO cause the problem that they take up most of the space along the back of the PCB. [Those not familiar with mini-ITX should know that where Michael has put the PBI and SIO are the back and would always be accessible on a ITX case.

 

So. . . that means that the 2 joystick ports and the PS2 ports would not be accessible unless you open up the case. It seems to me that one should put the ports that would get the most plugging and unplugging action at the back (always accessible). And in my opinion, the joystick ports would get a lot of the plugging and unplugging action (removed when not in use).

 

Whereas the SIO port would have something constantly plugged in. [Legacy floppy drive or printer.] Or at least one could always have the floppy drive connected and route the cable out the front or the side of the case (may require modifying the case).

 

One final comment/ question: could you stack the 2 joystick ports? And stack the 2 PS2 ports? similar to the image in this link? I realize it would be harder to do but would give you more space to work with along the edges of the board.

https://www.google.com/imgres?imgurl=http%3A%2F%2Ftechreport.com%2Fr.x%2Fam3-chipsets%2F790fx-ports.jpg&imgrefurl=http%3A%2F%2Ftechreport.com%2Freview%2F17061%2Fhigh-end-socket-am3-chipsets-under-the-microscope%2F2&docid=MPSfMSOw_0RyMM&tbnid=DOlHlAEJOH1zCM%3A&vet=1&w=600&h=255&bih=662&biw=1366&q=stacked%20ps2%20ports&ved=0ahUKEwjnu82rzNnRAhVl0oMKHdDDDNsQMwhEKB4wHg&iact=mrc&uact=8

 

Yeah I'm just playing around at this time nothing serious on the layout yet, but you are correct about the problem with not being able to put all the connectors on the back with the PBI taking up a good portion of the space. I've been thinking about it, and will opt to get rid of the right angle PBI in favor of another vertical one on the inside. The ribbon cable can always be snaked out over the top of the other connectors. And yes I'm looking at using a stacked keyboard/mouse connector.

 

 

Also. . .

If you find that all the chips won't fit on Mini-ITX, then Flex ATX is the next size up.

Size is 229mm x 191mm

And a lot of the cases that fit an ITX will also house a Flex ATX case (but not all obviously!)

 

Best of luck with the project.

 

I really want to stick to this smaller size if at all possible.

 

 

Thoughts of putting the IO ports on a PCI slot bracket? Actually, you could move some components around and have the standard required things out the back side, like PBI, PS2, Video, toss the SIO and joysticks on a bracket. Just a thought...

 

Haven't gotten that far yet, at least as far as things like this are concerned. But I would rather not have things mounted on a bracket, better if they were integrated into the board. Some stuff like the SIO2PC-USB daughter board should lend themselves to floating over the top of the less tall connectors, thus giving you that 2nd story without resorting to a bracket.

 

- Michael

Edited January 24, 2017 by mytekcontrols

[Kyle22]

A real SIO connector would not work well on a bracket. It's too wide, and also difficult to procure in that mounting configuration, and it would bend most brackets with the normal SIO insertion force.

 

IMO, the SIO connector should be on the board and fastened down.

 

Remember the XF-551 problem?

[+mytek]

Some layout changes... using Stacked Dual connectors for joysticks and keyboard/mouse (PS2). Design is still in flux, so expect more changes.

 

 

 

Updated Schematic (V1.X 1/24/2017): 1088XEL_V1_X_1-24-2017_schema.pdf

 

- Michael

[+mytek]

Layout: Component placement taking form...

 

 

 

At this point, I could sure use some dimensions on Rapidus and a VBXE to make sure I leave sufficient room for both. Can anyone help me out with that?

 

- Michael

 

EDIT: Yeah I know the Cartridge port is missing --- working on that

Edited January 26, 2017 by mytekcontrols

[BillC]

Michael:

 

One thing to consider is that it may be difficult to unplug the external PBI cable, you may want to think about using a header with eject levers. Below is an example from Mouser.

http://www.mouser.com/ProductDetail/Molex/90663-3501/?qs=sGAEpiMZZMs%252bGHln7q6pm8NDWwBzqQCNsiDTJItpGvg%3d

 

And another from Digikey

http://www.digikey.com/product-detail/en/omron-electronics-inc-emc-div/XG4A-5034/OR962-ND/1787165

Edited January 26, 2017 by BillC

[Keatah]

Are there sources for Antic, GTIA, and Pokey custom chips? Or will a working 400/800 need to be stripped for parts?

 

Also it would be interesting to make cases similar to what's shown here:

http://blog.iso50.com/19111/atari-computer-concepts/

[joeventura]

Put me down for one

[Smokeless Joe]

Every time I see an updated schematic or layout, I hear the voice of The Old Man from A Christmas Story looking at The Lamp and saying "It's indescribably beautiful!" The only problem is that I really AM looking at a thing of beauty! I'm really looking forward to getting one of these.

 

Will they be 100% roll-your-own or will there be any kind of kit available?

[Dropcheck]

If you are planning on having more than 1 PBI device internally, you are going to need some kind of buffering circuitry. Is that in the works as well?

[jvas]

As we are at the layout now: maybe it is worth considering the possibility to add existing HW upgrades, like VBXE/Rapidus. Can they be applied if the chips are arranged this way? Just thinking.

[flashjazzcat]

VBXE will need a video jack... preferably DIN13 with stereo audio on the ST audio out and audio in pins.

[+mytek]

Michael:

 

One thing to consider is that it may be difficult to unplug the external PBI cable, you may want to think about using a header with eject levers. Below is an example from Mouser.

http://www.mouser.com/ProductDetail/Molex/90663-3501/?qs=sGAEpiMZZMs%252bGHln7q6pm8NDWwBzqQCNsiDTJItpGvg%3d

 

And another from Digikey

http://www.digikey.com/product-detail/en/omron-electronics-inc-emc-div/XG4A-5034/OR962-ND/1787165

 

 

There should be enough room to put latching versions in, but they would now need to be vertical not right-angle (no longer have an external PBI connection). I'll update the layout to reflect the larger footprint that these require. ow 'm not saying that either one (or both) of these PBI connectors can't be used for external devices, but it will require the user to route a ribbon cable to the outside.

 

 

Are there sources for Antic, GTIA, and Pokey custom chips? Or will a working 400/800 need to be stripped for parts?

 

Also it would be interesting to make cases similar to what's shown here:

http://blog.iso50.com/19111/atari-computer-concepts/

 

Best and/or B&C should have the chips.

 

 

Every time I see an updated schematic or layout, I hear the voice of The Old Man from A Christmas Story looking at The Lamp and saying "It's indescribably beautiful!" The only problem is that I really AM looking at a thing of beauty! I'm really looking forward to getting one of these.

 

Will they be 100% roll-your-own or will there be any kind of kit available?

 

I'll never produce these for sale, but since the PCB files will be public domain any one can, and hopefully will roll-their-own. And perhaps if what I make is good enough, someone will produce a run of these for other people to buy.

 

 

If you are planning on having more than 1 PBI device internally, you are going to need some kind of buffering circuitry. Is that in the works as well?

 

Normally this would have been true in the TTL/LS days, but if a board uses HCMOS, at least two should work without buffering on my side. And of course if the devices remain internal with a very short interconnection you won't have the added capacitance of a long cable to drive into. And this is all good in theory, but of course the ultimate test with real hardware might not fair so well. However in my defense I have been working on ways to produce a much more precise buffered Phase 02 signal, which I think plays a big role in PBI devices not working correctly, especially when sharing the bus with other stuff.

 

 

As we are at the layout now: maybe it is worth considering the possibility to add existing HW upgrades, like VBXE/Rapidus. Can they be applied if the chips are arranged this way? Just thinking.

 

I think those upgrades will plug-in the way I have it now, but that is also the reason I requested help from someone, anyone that can take measurements off of these boards so that I can confirm this. Basically I only need the board outline and the relative position of the 40-pin piggyback pins. Do you have either of these boards?

 

 

VBXE will need a video jack... preferably DIN13 with stereo audio on the ST audio out and audio in pins.

 

I'd love to accommodate that request, but I've run out of room for doing so. The Mini-ITX form factor stipulates where and how much room is available for the connectors. I've already gone with stacked D-SUB9's and MINI-DIN's, and even stacked the SIO2PC-USB over the top of the coaxial power jack. And I don't really want to add any brackets to hold extra stuff above what is already there since it would likely require something custom in nature. But what I can do is add some mounting holes on either side of the audio/video jacks which can be used for such a custom bracket, if someone is ambitious.

 

 

- Michael