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Atari 64K Memory Card (Atari 64KMR) for 1090 xl expansion system

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18 minutes ago, ZuluGula said:

I'm aware of the differences between 600XL and 800XL. The solution would be simple adapter plate/pcb with PBI connector and plugs for power, video and SIO that will go into 1090 mainboard.   

Sure, and that's doable.  But once power, video, and SIO are added to the 1090's PCB, that moves substantially away from the original design and introduces additional cost and complexity.

 

For those, it would probably be better / easier to just run shielded cables inside the enclosure.

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1 hour ago, MrFish said:

Yeah, I'm just thinking out loud about practicality and cost. An exact replica is desirable, and probably easier to implement. I was thinking more about a longer term goal/option; but there's also the negatives that go along with having two standards.

Well I wouldn't exactly call a prototype that Atari never pursued past the development stage or got into the hands of consumers a standard. So realistically there is no standard as of yet in my mind, beyond the 1090 retro prototype re-make and a few recreated prototype cards to go in it.

 

Yes I know that through some very creative reverse engineering the 1090 that Atari envisioned is getting close to reality, and that in itself is very cool. But other than the few cards that Atari made including the one that has also been reverse engineered and what this topic is about, I doubt that there will be all that much in the way of new boards developed for it based on the fact that it is incompatible with all existing PBI/Cart-ECI products from a plug 'n' play standpoint (the slots are completely different)

 

32 minutes ago, DrVenkman said:

Since this device would be connected directly to the bus, you would have to be VERY careful to avoid adding capacitance and screwing up bus timing. Fast modern devices like SIDE3 are already problematic in some machines due to timing issues - many reports of people having to replace the 74LS08’s in their systems with faster 74F08’s to improve the BPhi2 signal enough to allow those machines to boot. Adding a long cable and multiple cards may not work out in practice. Issues like this at the prototype stage may well be what got the project killed in the first place.

 

27 minutes ago, MrFish said:

Wasn't there talk already about the use of some type of buffered/buffering cable?

Yes the approach of having a large parallel ribbon cable hanging out the back is just not practical and wouldn't lend itself to having the 1090 box more than a few inches away from the computer if you want this thing to reliably work. I believe it was @Spaced Cowboy that was working on a much better approach via a high speed serial cable, where there would be a small compact parallel-to-serial interface board plugged into the Atari's PBI for transition to the high speed 'skinny' cable that would go to the expansion box located many feet away if desired.

 

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Wow.. Lots of discussion!

As for the differences in the 600/800XL port layouts.  They could be setup to be loose and slid left and right as needed (NewerTech did something similar with the original G3 Apple PowerBooks and docking stations)..  there are several possibilities.  [The bigger issues is how would we apply these to the ECI XE's... and do they have all the necessary pins to be 100% XL PBI compatible].

 

R Chang already did some incredible drawings of XLs and docking stations and sit-behind pizza boxes, examples:

 

image.png.149a3528aa8803a02eed4bdde2be1a8d.png

 

image.png.a079a22c3b7d11eaa8bef17ea3490be3.png

 

 

 

As I recall, there originally questions as to if the PBI bus needed to be buffered, and I thought some of the early designs required a buffer box and I thought I read that one of the 1450 designs also had that.  [Lot's of 'I thoughts' in there... it's been a while]

 

I see a lot of merit in reproducing what Atari was trying to do at the time.  And then expanding from there.

 

And yes, the idea of a parallel-to-serial board with high speed transfer would be ideal for a dedicated box.

 

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And now to address the elephant in the room...

 

Has anyone on these forums ever actually used the 1090 system ?

 

Did it really work properly, and/or were there issues ?

 

Since these reproductions are based on Atari prototypes, the possibility exists that it might not really work all that well, and that too may have played into why it was never released.

 

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It was scrapped for a multitude of reasons, losses in market share, in cost reduction we lost the normal PBI and went to an ECI/CART on the XE series... just when PBI devices were gaining some traction, lame excuse from the top... no one has been or will be using the PBI... so SUPRA/ICD/CSS etc. had to come up with creative solutions... look at the pbi to eci adaptor cart cards and the very shape of the black box.

A 1090XLE might have standard PBI or ECI/CART slots alongside it's slots of even in between them.

 

Where do people get the thought that it didn't even work? This was moving along to the point that the enclosure was designed, produced, completely assembled and was being used. There are some weird ways of introducing negatives into this thread.

 

Full steam ahead chaps?

Edited by _The Doctor__

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No one’s suggesting it didn’t work - people are asking IF IT DID. That’s a subtle but significant difference, especially in light of the problems we know are inherent in the A8 bus design when you add additional capacitance and the attendant signal propagation delays that adding capacitance causes.


Rather than handwaving away these legitimate questions, Michael asks the important question. 

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Getting back to the parallel ribbon cable interface, and the very possible reliability issues with that approach...

 

When I was first developing the XEL-CFx IDE interface for the 1088XELs I initially had taken the approach of putting the buffering on the downstream side of the ribbon interconnect cable between the XEL motherboard and the IDE board. This is very similar to how the 1090 interfaces with the Atari bus, where the 1090 box incorporates the buffer chips.

 

On my first tests I had the IDE board directly plugged into the motherboard without any cable. It worked great in this configuration, but this wasn't how it would be done in the final application where the ribbon cable would be required. So long story short, several boards got sent out to BETA testers along with a 8" long ribbon interconnect cable. Well suffice it to say that even having that relatively short ribbon cable between the IDE board and the XEL was all that it took to see the whole concept crash and burn. Thus back to the drawing board to create the XEL-CF3 which placed the buffering right next to the motherboard, with the ribbon cable only being used for connecting to a passive IDE-to-CF adapter remotely, and then things started to work.

 

Based on my Atari hardware design experience, which is considerable, the 1090 has the buffering on the wrong side of the interconnect cable. Yes it might work, but I doubt that you'll be able to use much more than 4-5" of ribbon cable at best.

 

So this is why I asked the questions I did in my previous post.

 

2 minutes ago, _The Doctor__ said:

Where do people get the thought that it didn't even work? This was moving along to the point that the enclosure was designed, produced, completely assembled and was being used. Weird ways of introducing negatives into this thread.

How do you really know this ? I think it's time you come clean on what your background and relationship with Atari really was BITD. Otherwise this is all hearsay and rumor in my mind. Besides as Herb pointed out, I'm not trying to bash the 1090. I'm just asking whether anyone on these forums ever got to play around with one, and if any reliability issues were ever seen in that experimentation. And I do have very valid reasons to question this based on the information about my XEL-CFx development. Also before people rush off to have PCBs made and invest in the components to stuff the boards, I think we really need to know if this Atari prototype really ever worked properly, or has the reproduction even been thoroughly vetted in this regard ?

 

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Such reservations are rarely expressed for any other endeavors. How many carts, computers, add-ons, and mini whatever have been built without all of this... How about some of us do like everyone else has done... build the things and share? If something is discovered wrong, we work on fixing it and we enjoy the journey. This is part of the hobby and it's fun. Like so many artifacts that have come up over the years, we have lots to enjoy and discover. Who wouldn't love the 800 left side board to be out there for all to enjoy as well... maybe incorporate that into a 1090 multi I/O card for everyone also. Plenty of threads and sites already covered.

The reproduction is a work in progress... just like anything else, you have to expect things may change, just like every other replacement main board, project, or add on. The everyday user isn't running out to build this just yet. No one is selling complete kits or finished products. Can we tinker?

 

If you read I explained the buffer being on the cable connecting nearest the computer. It's name was the Julia FIFO cable at the time, but there were other forms and versions

Edited by _The Doctor__

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1 hour ago, x=usr(1536) said:

and @DrVenkman brings up a good point about replacing 74LS08s with 74F08s in some cases (I did). 

I thought @HiassofT had solved this years ago. You can shorten the Buffered PH2 signal with an LS123, a resistor and a capacitor. Use that shortened BPH2 for writes. Leave reads alone.

 

Edited by ivop
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1 hour ago, mytek said:

I doubt that there will be all that much in the way of new boards developed for it based on the fact that it is incompatible with all existing PBI/Cart-ECI products from a plug 'n' play standpoint (the slots are completely different)

 

26 minutes ago, mytek said:

Thus back to the drawing board to create the XEL-CF3 which placed the buffering right next to the motherboard, with the ribbon cable only being used for connecting to a passive IDE-to-CF adapter remotely, and then things started to work.

 

These two remarks are exactly why I chose a compatible bus for Project Jenny. Instead of being a backplane computer, this could also be a bay for PBI/ECI cards. It would only need a small PCB with buffering on the PBI/ECI computer side, a dual row pin header, and a cable to another PCB with pin header that plugs into one of the slots, and it's a cartridge and ECI bay :) Obviously you need to be careful with conflicting cards, or cartridges, but an R-Time and an OSS cart could be plugged in together, without using the pass-through :) Plus a SysCheck if you RAM or ROM is b0rked ;) 

 

The last 5 months not much has happened on the Project Jenny front, though. Other projects got in the way :)  But I plan on continuing this eventually. I have way too many edge connectors to not do it ;)

Edited by ivop
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Just now, _The Doctor__ said:

Such reservations are rarely expressed for any other endeavors. How many carts, computers, add-ons, and mini whatever have been built without all of this... How about some of us do like everyone else has done... build the things and share? If something is discovered wrong, we fix it and we enjoy the journey. This is part of the hobby and it's fun.

This is fine for developers such as myself who happen to have the excess income to do so. But the community shouldn't be expected to bear the individual cost if it doesn't work properly. Every device I put out there for public consumption has undergone a very extensive vetting process to insure the best chance for success, and to not waste everyone's money. Normally I see between 3-4 prototypes before landing on the final configuration that gets released to the public, and only a handful of BETA testers are subjected to the issues and the fixes that result from that development process.

 

18 minutes ago, mytek said:

How do you really know this ? I think it's time you come clean on what your background and relationship with Atari really was BITD.

@_The Doctor__ I'm still waiting on the answer to this question, which I think needs qualification before you continue to speak with authority on what actually happened concerning 1090 development at Atari.

 

I'm an open book when it comes to my history and qualifications on the subject of hardware design, so I think I've earned the right to speak with some authority on the potential issues involving bus interfacing to the Atari 8-bit. hence the reason behind my questions concerning the 1090.

 

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No one is asking the community to fund this... What purpose does this serve? I wasn't even done with my post and you are quoting away. Breathe. This has also been discussed in threads and forums. I think Curt posted some of it as well. On cyber roach you will find things there for people to see. Though you might have to use the wayback machine to see his 1090 et al

Strong arming folks seems to be all the rage these days. I prefer to keep things as they are. The forceful nature and demands are why so many steer clear of this stuff. Just be happy we share what we can remember and know up to a point.

Edited by _The Doctor__

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1 hour ago, mytek said:

Well I wouldn't exactly call a prototype that Atari never pursued past the development stage or got into the hands of consumers a standard. So realistically there is no standard as of yet in my mind, beyond the 1090 retro prototype re-make and a few recreated prototype cards to go in it.

I never said any standard exists; I'm talking about what would end up being two standards (if a replica 1090 and a 1090 updated version were created).

 

Edited by MrFish
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15 minutes ago, ivop said:

 

 

These two remarks are exactly why I chose a compatible bus for Project Jenny. Instead of being a backplane computer, this could also be a bay for PBI/ECI cards. It would only need a small PCB with buffering on the PBI/ECI computer side, a dual row pin header, and a cable to another PCB with pin header that plugs into one of the slots, and it's a cartridge and ECI bay :) Obviously you need to be careful with conflicting cards, or cartridges, but an R-Time and an OSS cart could be plugged in together, without using the pass-through :)

 

The last 5 months not much has happened on the Project Jenny front, though. Other projects got in the way :)  But I plan on continuing this eventually. I have way too many edge connectors to not do it ;)

This I like! just took a look... hope you continue with it!

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50 minutes ago, _The Doctor__ said:

No one is asking the community to fund this... What purpose does this serve? I wasn't even done with my post and you are quoting away. Breathe. This has also been discussed in threads and forums. I think Curt posted some of it as well. On cyber roach you will find things there for people to see. Though you might have to use the wayback machine to see his 1090 et al

Strong arming folks seems to be all the rage these days. I prefer to keep things as they are. The forceful nature and demands are why so many steer clear of this stuff. Just be happy we share what we can remember and know up to a point.

Jeez I'm not strong arming. I simply wanted to know what your background was concerning Atari et al, because I often see you post references and information that makes it sound like you worked for them. Funny thing is, you still haven't answered the question.

 

And I really sincerely wanted to know if the 1090 has ever been conclusively shown to work and/or not have issues with the ribbon interconnection between the box and the Atari computer's PBI. because quite frankly I don't think I've ever seen a video showing one in operation, or a review of how well it works. This led me to wondering if it really was ready for prime time. If you have links, please post them here.

 

I also wanted to curb people's desire to have a couple of feet of cable to place the 1090 off to the side or on a shelf away from the computer, because I don't have any doubt that would be an utter failure.

 

1 hour ago, _The Doctor__ said:

How about some of us do like everyone else has done... build the things and share? If something is discovered wrong, we work on fixing it and we enjoy the journey.

And my response to the expectation for people to just build this and hope and pray that it works correctly, and if it doesn't then they'll need to execute a possible plethora of fixes, just seemed unreasonable to me (not my response, but the expectation). I for one would never do that, as I think I've demonstrated many times in my own projects. Now understandably @kenames99 might not have the funding or inclination to fully test his recreated PCB designs, and we are all thankful that he did indeed take the time to design these recreations and share them. But the question still needs to be asked before others fork out money to build these - has this design been vetted ? If not then at least people know what they are getting into from the get go. Without tracing back through all the posts both here and about the 1090, I seem to recall that these recreated boards have not been fully tested, but I certainly could be wrong since my memory isn't what it used to be.

 

Edited by mytek
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On 9/13/2021 at 11:49 AM, ClausB said:

Looks like the board is already designed to handle 256K. Just plug in some 41256 DRAMs instead of 4164s, and plug a 74LS153 into U20 and you're good. (This will also require the newer ANTIC.)

 

I took the liberty of modding the schematic for 256K. In the process I found that U20 pin 1 must go to ground. It might help to remove R25 too.

 

256K 1066schematic.png

Edited by ClausB
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1 minute ago, ClausB said:

 

I took the liberty of modding the schematic for 256K. In the process I found that U20 pin 1 must go to ground. It might help to remove R25 too.

256K 1066schematic.png

A thanks to @ClausB,

Whose hand in so many projects over the years makes the time on AA worth it.

 

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Ok so I went back to the beginning of this topic and I see that the development and testing of this project has been ongoing by @kenames99 and @atari-passion. I should have done this earlier :dunce:

 

Anyway it's good to see that development is happening, and real PCBs based on this re-creation are being tested. All great stuff 👍 .  And from what I see in the posts, it looks like the system is working, although the ribbon cable does appear fairly short between the box and the computer, which is how I assumed it would have to be for reliability. In further searching I did come across a couple of very interesting videos by Curt Vendel that show him testing what was a mystery wire-wrap board in the 1090, and turned out to be an LCD driver board for the once destined Atari laptop.

 

 

 

EDIT: very cool to see the 1090 80 column card running in that first video. Any plans to duplicate that? Does someone have the schematic or that actual board to reverse engineer? And of course a dump of the ROM(s) will be needed as well.

 

Edited by mytek

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Hello guys

 

Just toke this picture.  600XL on top, 800XL on the bottom:

 

1153225583_Backside600XL800XL.thumb.JPG.d930e0a38b1c4f6ce71e19400f2a0763.JPG

 

Sincerely

 

Mathy

 

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1 hour ago, ClausB said:

 

I took the liberty of modding the schematic for 256K. In the process I found that U20 pin 1 must go to ground. It might help to remove R25 too.

 

256K 1066schematic.png

hi ClausB,

  thank you for this update! your expertise is always appreciated.

 

Ken

 

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1 hour ago, mytek said:

Ok so I went back to the beginning of this topic and I see that the development and testing of this project has been ongoing by @kenames99 and @atari-passion. I should have done this earlier :dunce:

 

Anyway it's good to see that development is happening, and real PCBs based on this re-creation are being tested. All great stuff 👍 .  And from what I see in the posts, it looks like the system is working, although the ribbon cable does appear fairly short between the box and the computer, which is how I assumed it would have to be for reliability. In further searching I did come across a couple of very interesting videos by Curt Vendel that show him testing what was a mystery wire-wrap board in the 1090, and turned out to be an LCD driver board for the once destined Atari laptop.

 

 

 

EDIT: very cool to see the 1090 80 column card running in that first video. Any plans to duplicate that? Does someone have the schematic or that actual board to reverse engineer? And of course a dump of the ROM(s) will be needed as well.

 

hi everyone,

  seems this has turned mostly to a discussion about the 1090XL, so I would like to see it move to the 1090xl remake thread at 

but if that would kill the discussion then here is ok.

 

  I also want everyone to know this whole project is not a reverse engineered or hacked out thing. I downloaded all the schematics and mechanicals from atarimuseum.com before it went offline. by downloaded I mean that I mirrored the site. I am going by all the original schematics and mechanical drawing to enter into kicad. that is what is available on my github. 

 

  I have assembled a 1090XL board I had made and that seems to work fine as I posted earlier iin this thread. Currently waiting on more parts for the ram board and ribbon cable for xl to 1090 connection.

 

  if there are any questions you can feel free to ask. thanks for all the comments and viewpoints.

 

Ken

 

Edited by kenames99
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6 hours ago, ClausB said:

U20 pin 1 must go to ground

 

From the board photos it appears that U20 pin 1 goes to U21 pin 19. If so, that's fine and it doesn't need to go to ground.

 

It also appears that U20 pins 1 and 16 are connected. That's bad. Pin 16 should connect to +5V,  not to pin 1.

Edited by ClausB

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It's hard to tell from the photos whether those are copper connections or just silk screen lines. Could someone post a close up photo of U20 and U21 on the bare board, maybe both sides?

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17 hours ago, ClausB said:

It's hard to tell from the photos whether those are copper connections or just silk screen lines. Could someone post a close up photo of U20 and U21 on the bare board, maybe both sides?

@atari-passion, would you please?

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19 hours ago, ClausB said:

It's hard to tell from the photos whether those are copper connections or just silk screen lines. Could someone post a close up photo of U20 and U21 on the bare board, maybe both sides?

hi ClaudB,

  do you mean the original board or the remake one? if you meant the remake one I did, I have included them here. there was an extra line across pin 1 of U20 on the silkscreen layer. I have removed it a while ago, it was just for physical alignment purposes.

1066.pdf 1066sch.pdf

Edited by kenames99
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