Does the ColecoVision + SGM = the ADAM?

[Pixelboy]

1 hour ago, MrPix said:

I'm currently working on a CV clone - not an FPGA implementation, but a direct board replacement that has modern power regulation, and part of the SGM capability built in (the larger RAM and more granular address decoding). It has the RGB circuit directly built in, and would be used for repairing dead CVs where the motherboard is beyond economic repair. It only requires a donor 9928 or F18A.

I released my first expansion in 1984, released the very first 512K expansion with battery backed clock for the Amiga, the Sam Coupe breathed its first breath of life on my bench. I was one of the designers of the translate lookaside buffer on the first ARM with cache. I'm not here to throw out "I've been doing this longer than you." I respect what you've managed to do with somewhat limited resources.

I literally just said I have no plans to make an SGM. I don't compete with existing traders. I work to improve the hobbyist scene, not compete with people and harm their livelihoods.

Just my (very small) two cents here: A drop-in replacement CV motherboard is a good project, but if you want to really raise some eyebrows and make history in our little community, I would recommend something that was discussed repeatedly but never actually done: An Intellivision expansion module. Not sure if this is a project that would actually interest you, and I have to admit that I'm not personally all that interested in the Intellivision myself, but on the other hand, given your technical credentials, this seems like a challenge you could have fun tackling. 

 

Again, just my two cents.   

[MrPix]

I have got an Inty project on the go, to produce clean RGB output from the AY-3-8915. All I can say is that, and I'm quoting myself, "It's like someone designed a console because they really wanted a console, but they didn't know what one looked like and had never seen one."

The GI chipset is a festering abomination of bad ideas, for the main part. It works, but only with itself. Fortunately, the 8915 is the simplest IC, and I can work with the signals sent to it by the STIC (which in the Inty is a sort of proto-VDP/memory manager/bus supervisor, a job it shares with the RAM, which is also not just RAM but has other complex functionality too).

I'd be more inclined to incorporate MSX functionality.

[youki]

4 hours ago, MrPix said:

I'd be more inclined to incorporate MSX functionality.

A MSX expansion module  would be great for me.  Something that allow you to run directly MSX Cartridge on Colecovision.   Like that some homebrew developpers will have more time to create original games for the colecovision instead of using that time to port MSX game to SGM.

 

Or may be less interresting for you in the U.S. but may be for others,  the opposite a Colecovision Expansion Module for MSX.    This kind of module already exists for Spectravideo SV318 which very close to msx standard but not a msx. I don't think such a module exists for real MSX.

 

 

[Tursi]

It'd be pretty awesome to plug an MSX expansion into the front of a ColecoVision, actually. I don't know enough about the MSX architecture but I took a quick look online. The MSX memory map would be a full replacement anyway, so you'd have to turn off the Coleco's ROM and RAM, but I think the kicker is that the MSX needs a tighter decode on the I/O space (and the VDP is at a different port anyway). Without providing your own Z80 as well I don't think you can work around that (?), and once you've got ROM, RAM, and CPU, is it even worth using the Coleco's VDP? (That said, the 2600 module didn't even use that, so hey! Maybe! )

 

[MrPix]

I'm a hardware guy. One of my Mad Skills™ is address decoding with aliases. I can alias the VDP using a bridge so it can be at one location in one machine and another in the other. This way, I can remap everything, and just disable the internal CPU. From there, it's just a matter of making the CV/Adam think there's a cart in the built in slot, when an MSX cart is in the expansion slot.

[NIAD]

On 6/16/2020 at 9:29 AM, MrPix said:

Announcing the CGM1, the "Cute Game Module" - an AY-3-8910 for the Adam.
 

That was already made a couple years ago by, IIRC, AtariAge member chart45. He shared full details in this forum including schematic. I have everything saved from the thread and will have to search it up when I have some time.

 

i actually owned a JuiceBox Say Game Module and it worked really well. They were housed in repurposed SNES carts which fit nicely into the Expansion Interface. I heard there were some kind of issues, possibly when used on an Adam, but I only used it on a CV. The Speech Synthesizer addition was a nice addition but only ended up being supported by the included test rom image. I ended up passing it on to another CV owner who was desperate for a SGM when they couldn’t be had except for the ones that were selling on eBay at the time in the $300 or more range. The developer proved to be a complete POS and has since moved on.

[Tursi]

7 hours ago, MrPix said:

I'm a hardware guy. One of my Mad Skills™ is address decoding with aliases. I can alias the VDP using a bridge so it can be at one location in one machine and another in the other. This way, I can remap everything, and just disable the internal CPU. From there, it's just a matter of making the CV/Adam think there's a cart in the built in slot, when an MSX cart is in the expansion slot.

I can do that too, that's why I suggested it would have to be done that way. What I questioned was "why bother attaching it to the ColecoVision at all when you've already gone that far?"

 

If you disable the internal CPU, you don't need to make the CV think there is a cartridge in the cart port, though, cause nothing will be executing it anyway.

Edited June 19, 2020 by Tursi

[Pixelboy]

3 hours ago, Tursi said:

If you disable the internal CPU, you don't need to make the CV think there is a cartridge in the cart port, though, cause nothing will be executing it anyway.

Yeah, the Expansion Module #1 surely doesn't look for a cartridge in the CV cartridge port, and it bypasses the CV's VDP altogether.   

 

[Loafer]

21 hours ago, MrPix said:

I released my first expansion in 1984, released the very first 512K expansion with battery backed clock for the Amiga, the Sam Coupe breathed its first breath of life on my bench. I was one of the designers of the translate lookaside buffer on the first ARM with cache. I'm not here to throw out "I've been doing this longer than you." I respect what you've managed to do with somewhat limited resources.


 

Apologies on the small side step on this thread.  As a huge Amiga fan and admirer of all classic VG hardware, thanks for your past (and apparently current) contributions!

 

Back on topic, sadly it is just a matter of time before many current colecovision owners have a dead system on their hands.  The system is almost 40 years old, so having modern replacement hardware that can more or less be dropped in is huge.

[MrPix]

I think so too.

As a hardware maker, the part that excites me is the PCB layout and the assembly. I'm not really a salesman, though. I'd rather pair up with somebody who could do the customer-facing stuff. I suspect a lot of people would need help to desolder and transfer the VDP, so I was thinking of pairing up with someone like Ruggers Customs for that.

[Tursi]

That said... I think NOS 9928s are still available... or pair up with Matt and use F18A's. He's pretty close now - they should be ready by the time you have a PCB.

 

I've got a half dozen 9918As laying around pulled from TIs, but that doesn't really help a Coleco clone unless you want to put options on the PCB - jumper to select YCrCb or Composite out from the VDP

 

[MrPix]

He told me he was going to make the F18A mk1 open hardware a short while after releasing the mk2. If he follows through with that I’ll happily produce a batch. 

[NIAD]

On 6/16/2020 at 8:29 AM, MrPix said:

Announcing the CGM1, the "Cute Game Module" - an AY-3-8910 for the Adam.

Hehehehe

Found the info on Chart's AY-3-8910 interface for the ADAM. Could be used on the CV as well, but really no point for obvious reasons.

 

ADAM AY-Sound (SGM) Interface (2019) (Chart).zip

[MrPix]

Nice little board.

Love the blacktopped 8910