More Chipram

[stopthegop]

Anyone know of a way to increase chipram beyond 2M in an A4k?  I thought I read somewhere about a hw hack that could be done to accomplish this but its just been so long I don't have a clue where I read it..  Or even IF I read it.    Anyway, the question is: Can this be done?

[Flashlab]

Sorry it's not possible...

[bloodline]

Actually it is... you just have to find the "Free sex and beer" jumper...

[Zac67]

You'd just have to put in an 8M Alice, add some piggy back RAMs and change J214 to the 8M position.
However, the 8M Alice does not exist, so you'd have to do a bit of redesign... :-(

[motorollin]

You would also have to solder in a line for an extra data bit to allow the rest of the system to address >2MB.

--
moto

[MarkWatson]

How about having a 512K bank switched window inside the 2MB region using some general IO lines or something? Even better when its switched out it could be mapped into fast RAM area. So to update the screen you write to fast RAM, set a bit, it becomes chip RAM. Very fast screen updates are yours...

Mark

[Piru]

I wish people would learn to use the search

[Flashlab]

Hehe wishful thinking; it's not Christmas yet ;-)

[weirdami]

What about piggybacking 3 extra Alice chips. Maybe like a 4 Alice chip board that plugs into the Alice socket. That would be neat.

[stopthegop]

@Piru
You mean "search" the Internet?   Tried that.  No luck.  Searching a much more effective medium now: people's brains.  There is definately a way to do this.  The hurdle to overcome in this case is one of limited resources, not technical feasibility.  What the Amiga community lacks in resources, however, it more than compensates for in its resourcefulness!  This will be solved with pure ingenuity, imho.  

Chronic pessimism -- or as the pessimists call it, 'Realism' -- doesn't help much.  There's ALWAYS a way... no matter what the problem is.  If pessimists (sorry, "realists") had been listened to throughout history we'd all be travelling by mule, communicating via carrier pigeon, and marrying our relatives.  Actually, that all still happens in the bible belt of Central US (sorry, could resist).      Anyway...I'll give one example and then be quiet.  

Ever hear of Prescott Eckert?  He built the ENIAC for the US Army in WWII.  ENIAC was the world's first 100% digital computer, btw.  Guess how many people told him "it can't be done" ove the 5 or so years it took him to build it?  Everyone except his dog, pretty much.. Its a good thing he didn't listen to the surrender monkeys.    

[Flashlab]

Well the resourcefulness you're talking about already made it possible to have 8Mb of ChipRAM; in WinUAE that is...

Don't want to sound pessimistic in your book but I don't think we'll see it in Classic Amiga hardware. There shouldn't be a specific need for it either. Why do you want it?

[KThunder]

resourcefullness is a great asset. it has allowed us to do lots of things with our amigas, from accelerator projects to usb to mp3 stuff. but there are things we cant do unless we have deep finacial resources. the 8meg chipram would require a chip redesign. is it possible yeah, likely not at all.
ive never run into chip ram problems. maybe im the only amigian who has. there are lots of things you can do to get around chip ram constaints. why dont you let us know what you are trying to do and see if we can help that way. esecially before you start posting insults. (no im not from the bible belt, nor am i married to a relative)
we have all known about chip ram for a very long time, so have programmers there is a lot that can be done even with 1meg of chip ram.

[Matt_H]

Look, read the thread that Piru linked to. This has been discussed to death already. Dave Haynie, the designer of the system architecture, has stated over and over that it's not possible without a major rework to the chips. End of discussion.

[TjLaZer]

Stopthegop, no Peru meant search Amiga.org, as he provided a hyperlink in his reply, click on it

[LoadWB]

Now this is just academic, for the sake of argument.

On my big box systems (2000 with MegAChip and 4000) with graphics cards, my ChipRAM RARELY dips below 1.8MB or so.  My 1200 is a different story as it has nothing more than standard AGA.  I will leave the 500 out of the discussion ;-)

Out of sadistic curiousity, with the number of people working on hardware emulations of the Amiga system, would it be possible to design a cheap replacement Alice to allow the 8MB Chip RAM for those using standard AGA, or would more need to be done?

Since the chips on the 4000 are not socketed, a MegAChip-style upgrade is not viable -- the upgrade would need to be an over-chip design, like accelerators for the 600.  It is also apparent to me that the 1200's design lacks the support for such a hack.