Atari 800 / Sophia-2 Install: Letting ANTIC and GTIA be the best they can be....

[Faicuai]

Let's admit it: with the already excellent stock video quality you can extract from even a stock 1980 CTIA 800, the more we think about a video-interface upgrade solution that would not only bring our fleets into today's digital, large-screen formats, but also securing our precious retro-experience, just the way we remember it !!

 

Enter SOPHIA-2:  RF, Composite, S-Video and multi-resolution Analog and Digital video-interface (over DVI) with just a simple swap of your existing GTIA ! In other words. a truly native, digital video-interface upgrade that will not cripple your existing analog video-generation assets, and with a pretty low power-consumption profile!!

 

Now, I am not sure about you, but any trace-cutting, shields de-gutting, or external plastic case "carnage" on the 800 not only is out of my scope (as a collector), but it will quickly bring my inner "psychopath" out in full force (don't ask me why). Therefore, if you are wondering about a simple, constructive way to install Sophia while leveraging the 800's architectural benefits, this one may be for you.

 

Let's start by some words of caution and scope:

 

1. There will be TWO types of CPU-boards that you will likely find:
   • Older, standard 6502 CPU version, or... Newer revised, simplified Sally 6502 version.
   • BEWARE that the pin-orientation of ALL system chips is REVERSED between these two boards.
   • Although I have these two types at my disposal, this guide covers installation on SALLY (1983) CPU board..
   • If your CPU board is the older type, you can follow this guide with the exception that SOPHIA-2 will have to be installed with the opposite orientation as you see here (that is, Sophia's pin-1 will be near board´s bus interface). Failure to do so will DAMAGE your Sophia-q board, terminally:
   •  
   •  
2. Sophia's video-ribbon length is a function of your chose EXIT PATH from CPU board. You may end up needing MORE  than 12" (30cms) of length!
3. There will be NO soldering and NO cutting or non-reversible modifications to the 800's external case or internal frame. 
4. The only two fully-functional (and invisible) modifications will be:
   • Top shield-plate (underneath removable top-cover). This elegant and simple change will serve you well for Bit3, Incognito's PBI bus-extension ribbon and Sophia-2 video-ribbon. It is basically a mandatory upgrade if you are serious about 800´s expansions, plus it will improve expansion-bay cooling.
   • Internal small guide-slot on plastic-frame of expansion-bay,  to allow underneath passage of video ribbon from CPU compartment into expansion-bay (for a final exit path right under top-cover existing space-gaps).

 

So without further ado:

 

• STEP #1: General Preparation:
• GENTLY and SLOWLY remove supplied precision-socket from your Sophia-2 assembly. you will NOT needed it.
• GENTLY Remove 800's bottom case (5-screws),  detach from top-case (3-screws) and detach bottom shield-MoBo assembly (9 screws)
• Unhook MoBo/Shield-plate from power board, and unhook expansion bay tray by GENTLY prying its four hooks between MoBo and shield-plate (accesible through right and left sides of shield-plate assembly).
• STEP #2: Extract CPU-board from its slot and GENTLY and SLOWLY remove your GTIA from existing socket (outer-left in Sally board). SLOWLY and uniformly seat-and-press SOPHIA-2 on CPU-board GTIA socket, as DEEP as you can. WARNING: it turns out that sockets are NOT all built to the same tolerances, and you may end up with a partial seating or FULL seating. BOTH will end up working.
• 
• The reason for the above is how close the integrated video-ribbon pin-header ends up with respect to the socket's frame, as shown of left-picture above. These variances will show up even on the SAME TYPE of CPU board!!! (trust me, I have several ones!)
• Gently fold video ribbon over Sophia, for exit path on left of board (shortest-possible) and and slightly slant downward before wrapping on the back of the board, as shown:
• 
• WARNING: notice the tolerances and clearance required on the riobbon-side of Sophia. If your CPU board DOES NOT have the required space between ANTIC and GTIA, or you have passive components right underneath Sophiia's integrated red-header, you *WILL NOT* be able to install it on your CPU board.
• Now proceed by preparing guide-slots on expansion-bay plastic-tray. You will need a rotary tool for this, grinding slowly and gently. If you DO NOT want to do this, simply store the plastic tray in a safe place where you can restore it back if you ever decide to uninstall Sophia. This is how it will end up looking if you are gently (exactly the same approach for Incgonito's MMU ribbon, at the front):
• 
• Not its time to re-install plastic tray, CPU board and GENTLY bend and guide Sophia ribbon through its new, discrete exit path. It will look like this:
• 
• WARNING: I installed a very thin, protective plastic film (transparent) between CPU board and Sophia's ribbon, on the back (between Plastic try back wall) just to make sure that CPU board's solder-through pin vestiges do not pinch Sophia's ribbon. Just a precaution, you may not need it, depending on how low you position the 90-degrees ribbon fold.
• Remember those THICK, meaty shields on the 800? Well, if there is any RF radiation coming out of Sophia, they will now serve you well. And if they can't trapp it, NOTHING can ! :-)) Both seating-variants of Sophia will end up fitting, as I could tell (my CPU board socket ended up handling a FULL seating of Sophia):
• 
• Now we are ready for final re-assembly, in exact reverse order. It is also time to inspect the 800's internals for corrosion... First and foremost place is the crappy tin-frame of the RF modulator (same crap as my 800 XL's shields). It appears looks like mirror-glass on my 1983 daily-driver 800. Not bad for 9 years since its last opening:
• 
• On final assembly, notice the discrete and clean exit path of the ribbon, from the bottom of the plastic frame. The slots we made are not invisible, and will also allow you to retract and store the video ribbon INSIDE The expansion bay, for absolutely no external signs of Sophia-2 install:
• 
•  
• Now proceed with final case assembly, and notice the final modification required on Top-Cover shield (notice the slot, left is original untouched, and right is my "trainer" cover, where you can seen the modification):
• 
• Upon final assembly, my 30cm ribbon barely made it, but looks celan and minimalistic, just the way I like it:
• 
• And now onto my next adventure... building upon the strengths of Sophia, LCD / flat-screen and video-processor framework, for building a dual-screen setup... but that will be another (crazy) story....
• 

 

Enjoy!!!

 

 

 

 

 

 

 

Edited February 20 by Faicuai

[Mazzspeed]

May I say, you have a very neat 800 and I like the fact you take such pride in it, right down to the labeling regarding the ports. Can I ask (bearing in mind my intention isn't to criticize, as my game playing skills aren't good enough for lag to be a problem), but out of curiosity does Sophia(2) use a frame buffer?

 

Neat install BTW, right down to the nice slim ribbon cable poking out the back of the hatch.

[Faicuai]

49 minutes ago, Mazzspeed said:

May I say, you have a very neat 800 and I like the fact you take such pride in it, right down to the labeling regarding the ports. Can I ask (bearing in mind my intention isn't to criticize, as my game playing skills aren't good enough for lag to be a problem), but out of curiosity does Sophia(2) use a frame buffer?

 

Neat install BTW, right down to the nice slim ribbon cable poking out the back of the hatch.

Forgot about the labels !!! 😂

 

Yep, I "proudly" fried an Incognito board for mistakenly plugging it on Slot-1, instead of Slot-0 (thus the reminder of my costly mistake, especially as I grow older... ) That happened because Slot 1 to 3 have +5, -5  and +12 volts on pins where there are not such on Slot-0. And for the rest of them, I actually happen to have two curious minds around that have already wondered about what is what. Just want for that A800 to last a bit longer...

 

Sophia probably has a frame buffer, it is my speculation. However, what I can say for certain is that it is a notch faster than the DVDO iScan/HD+, and that one is pretty fast, already.

Edited February 20 by Faicuai

[Mazzspeed]

23 minutes ago, Faicuai said:

Forgot about the labels !!! 😂

 

Yep, I "proudly" fried an Incognito board for mistakenly plugging it on Slot-1, instead of Slot-0 (thus the reminder of my costly mistake, especially as I grow older... ) That happened because Slot 1 to 3 have +5, -5  and +12 volts on pins where there are not such on Slot-0. And for the rest of them, I actually happen to have two curious minds around that have already wondered about what is what. Just want for that A800 to last a bit longer...

 

Sophia probably has a frame buffer, it is my speculation. However, what I can say for certain is that it is a notch faster than the DVDO iScan/HD+, and that one is pretty fast, already.

Oh no...Really? Was the Incognito totally fried?

[Faicuai]

14 minutes ago, Mazzspeed said:

Oh no...Really? Was the Incognito totally fried?

It partially survived the shock... but with loss of 'short-term memory" 🤪😉 

 

BIOS settings are lost upon leaving BIOS, and always goes back to Profile 1. In fact, it is unable to navigate anywhere beyond profile 1. ROMs, however, are there, and it does boot manually the one that appears selected by default.

 

It seems that the CPLD needs to be replaced (that's about it). With the right tools it is a simple job, but I don't have those tools (nor I am going to buy them, though). Will have to wait for another way to repair the board (it is #1 out of 3 units I have here).

 

 

[flashjazzcat]

Sounds like the little DS1305 RTC chip is returning.nothing but zeros from NVRAM.

[Mazzspeed]

27 minutes ago, flashjazzcat said:

Sounds like the little DS1305 RTC chip is returning.nothing but zeros from NVRAM.

Kinda like my short term memory...

 

As I get older I'm noticing a lot more zero's.

[Faicuai]

7 hours ago, flashjazzcat said:

Sounds like the little DS1305 RTC chip is returning.nothing but zeros from NVRAM.

Well, your initial thinking is close to Lotharek's as well... but I was recently told by Incognito's chief-designer that blowing NVRAM chip was close to impossible (on that case0, and what was most likely damaged was Xilinx. Both require SMT disordering / soldering work, which I am definitely not going to gear up, for.

Edited February 20 by Faicuai

[flashjazzcat]

1 hour ago, Faicuai said:

I was recently told by Incognito's chief-designer that blowing NVRAM chip was close to impossible

Fair enough. I've had to replace a dead RTC chip before, but maybe you blew the data lines on the CPLD going to the DS1305. I'm just thinking that it makes no sense to plan to replace the CPLD when it's much easier to replace the component which appears to have failed on an otherwise fully working board.

 

[Faicuai]

1 minute ago, flashjazzcat said:

Fair enough. I've had to replace a dead RTC chip before, but maybe you blew the data lines on the CPLD going to the DS1305. I'm just thinking that it makes no sense to plan to replace the CPLD when it's much easier to replace the component which appears to have failed on an otherwise fully working board.

 

Exactly my thinking (prior to what I was told about it...)

 

Unless we try the DS1305 first, anyway... 🙂

[Faicuai]

Just a quick update on image quality after quite a long (snd deep) test with Sophia-2:

 

HOLY SMOKES!

 

 

 

 

 

(all the above on 720*480 Progressive output. and upsampled to 1280x1024 by Viewsonic VP950b LCD monitor's scaling engine! At native 1280x1024 output from Sophia, acutance and edge-definition is EYE BLEEDING!)

 

Besides the enhanced color gamut and saturation boost (with NO loss of tonal separation along the way), what is striking is the jump in CHROMINANCE resolution (eg. Laberynths of Khamerra). and effective LUMINANCE resolution during motion-oriented content... In the luma department, effective detail appears rendered down to pixel-fine quality (emulation-class), and in the chrominance department it easily uncovers the limits of s-Video (I have a dual-LCD setup, and can simultaneously watch ny given pair of video-interfaces vis-a-vis). There are obvious inaccuracies with the built-in color Palette but we will easily address them as soon as I can get a copy of a sample palette file.

 

In fact, the image quality jump on LCD rendering effectively blurs most image-quality differences with a CRT screen, leaving everything up to the LCDs inherent speed to handle fast changes of luminance, as well as the speed-of-light factor which will always be on CRT side.

 

I just can't imagine that mythical dual NTSC/PAL CPU+Sophia board for the 800... the holy-grail of video-interface upgrades, for sure!!

Edited March 29 by Faicuai