Could ColecoVision's 8K RAM space be utilized

[+mytek]

4 hours ago, marauder666 said:

On my ancient Sony BVM.

Here's a thread I posted when I got the machine a few months ago, some more pics.

Wow that's horrible

 

The jail bars I'm presently seeing in my project are very subtle, nothing at all like you are experiencing.

 

I'm still tinkering to see if I can eliminate even the ones I have.

[+mytek]

Started a new topic to cover the project that will incorporate many of the things being discussed here. I think it's kinda overdue, but I was also waiting to determine if I was really going to take on the BIG project for the little board. Well guess what... I am

 

 

I still plan on also creating a new topic for just the S-Video upgrade, but until that happens we can continue that discussion here.

[Bruce Tomlin]

On 9/19/2022 at 7:28 PM, mytek said:

What I was really wondering about... is having the 8K of RAM fully addressable instead of mirrored several times like the stock RAM, cause any potential conflicts with existing games?

 

And then the 2nd part was whether there would be any benefit to the extra 7K of RAM in that area?

I don't think there will be any conflicts. Some games are assembled for 6000 and others for 7000, but you would have to go out of your way to actually depend on the mirroring. I've disassembled most of the games and never saw any hint of that.

 

Will it be useful? If you do your own stuff just for fun, sure. The lack of an installed base will prevent it from being useful for homebrews unless your code can fall back to 2K. At that point a drop-in mod might get some popularity, but it will still always be harder to install than adding more RAM through the front slot. The obviousness of this mod is a big plus, though.

 

But as part of a replacement board that you already want to make? Go for it!

[+mytek]

5 hours ago, Bruce Tomlin said:

But as part of a replacement board that you already want to make? Go for it!

Yeah I just ended up going for the full 32K, but it's good to know that the lack of RAM mirroring isn't really going to be an issue.

[massiverobot]

On 9/20/2022 at 4:18 PM, mytek said:

I'm actually aiming this at supporting the AtariMax Ultimate SD Cart (or iffor someone that already has a physical cart collection). Really looking for fast loading which the SD Cart does very well, whereas FujiNet is kinda slow in comparison. I will try to squeeze in the expansion port for maybe a future FujiNet interface, although if it happens, it'll be a pin header.

Sure, if you have a pin header for ADAM net (RJ11 even) that is all you'd need for the FN, and a printer if someone wanted to print out on it!

 

[+mytek]

1 hour ago, massiverobot said:

Sure, if you have a pin header for ADAM net (RJ11 even) that is all you'd need for the FN, and a printer if someone wanted to print out on it!

Actually there ended up being no room for a standard expansion port to exist in my project (unfortunately). And I was forced into having to off board some components as a plug-in daughter board because of the extremely limited space a 4.5"x4.5" board affords. I don't think you fully grasp how little room there is for ADAMnet to exist in what I'm trying to make. Because more IC chips would be required beyond Colecovision to bring that into reality. Simply put, those chips would have to fit somewhere, but there is no space left for them to go.

 

Unlike the 576NUC+, I'm trying to keep all the glue logic on the main board to be THT. Aside from the ease in doing a DIY build in this fashion, it also allows a much easier troubleshooting experience if you can swap out chips via plugging them in and out. I wasn't able to do that with the plug-in daughter board aspect, but obviously that board can be swapped, and its not too complcated of a build on its own.

 

To tell you the truth I haven't been able to find much in the way of a decent schematic for the ADAM, whereas there are two very nice ones that were created for the Coleecovision by independent parties. The schematics I have found are total crap low resolution scans of the originals. It gives me a major headache to try to trace things out no matter how much zooming in and out I do, and I just got to the point where I threw up my hands and  said F___ it!  So unless someone out there has redrawn how ADAMnet is implemented, and what chips are involved, I'm just flying by the seat of my pants on this. However I do know that there is a separate microprocessor chip that deals with all the peripherals, including ADAMnet, and that there would need to be some serial conditioning circuitry involved as well. Bottom line still no room