I was planning on picking up a Pismo this weekend. It's a 400MHz. I was reading up on it to find that the ATI Rage chip in it supports up to 16MB of VRAM(?). So my idea is to find tha same type of memory, desolder the 8MB and solder on a few new chips to be 16MB. Would this work, or would I need to do some poking around in OF?
Thanks
if it supports up to 16mb vram, it should see it with no issue. but it depends if there is room to add enough chips to total to 16mb.
i think the GPU is what controls the vram. and not OF. i think OF is used to use the GPU and the GPU does the rest
Ok, thanks. I think I'll play around with the Pismo for a while before risking killing it then I'l give it a go.
A question I'd probably follow up before giving it a go is whether larger chips or *more* same-sized chips is the answer.
I thought about that Dr, but I'm pretty sure there's no extra spaces for more of the same size chips. I'm not even sure of the chip configuration. If it's like some of the newer ATI chips, the VRAM is soldered right on the chip, in which case I'm screwed.
I can't seem to find a MotherBoard picture with the Graphics heat sink removed, so I'll have to find out for myself...
Big Huge Nasty URL
According to Apple, the version of the Rage 128 Mobility they used has 8MB of embedded video SDRAM. So you're pretty much SOL.
I seem to remember reading once in some ATI technote that the Radeon Mobility 7000, direct successor to the 128 Mobility, was a "drop-in" replacement for the older chip. (It didn't precisely say the pinouts were the same, however. It just implied it was an easy product upgrade.) *If* the pinouts were the same I suppose in theory with BGA rework equipment it might be possible to swap in the newer chip along with its greater amount of embedded RAM. Good luck with that. ;^)
(In addition to the hardware swapout don't forget you'd need a new video BIOS. Maybe hack the firmware image from a second-gen TiBook...)
--Peace
I WISH I had my own BGA deballing and reballing equipment lol. I would definitely give that a shot if I did, but for now, I think I'll just take a peek inside the Pismo and see what I can do.
I had an idea for making a BGA desolderer, using a bunch of pins, but my idea would require access to the back of the motherboard where the BGA is.
BTW, at the point of getting a chip balled on there, I'd scrap the whole orig motherboard and processor, and design my own C2D motherboard and processor daughter card, using the MacBook Pros components and firmware, but this is a hack for when I have lots o' $ and am REALLY bored.
If you can do it, that would be awesome. But if the VRAM is really integrated into the GPU, then it's probably beyond any mere mortal (er, hobbyist) to do this mod at home. For what it's worth, I tried upgrading a Wallstreet to 8 MB of VRAM. The WS II has solder pads for a SO-DIMM connector, and the SO-DIMM it takes is the same size as the SGRAM SO-DIMM on the beige G3.
http://www.alksoft.com/projects/wallstreet_vram.html
I swear I wrote up a full story on the completion of the project. Anyway, a long story cut short: The extra 4 MB of VRAM weren't recognized by any tools I could find (for that matter, no tool that I could find at the time would report how much VRAM was installed even on stock Wallstreets). The LCD's colors got funky (there were a lot of extra green pixels) when I installed the SO-DIMM, though, so something did work out in the electronics of the hack... I never did get around to testing it empirically with an external display to see if I could get more colors at higher resolutions than with the stock 4 MB. Maybe some day I'll go back to that hack and see if I can get it working. I'm probably just missing some resistors or caps somewhere.
Oh, here's the post on the old YaBB forums about this: long URL
Peace,
Drew
alk, i really hope you figure that out. i'd love to get more vram in my wallstreet so just maybe it could play movies smoother (an upgrade cpu won't do it alone i'm sure).
Are you sure there isn't a couple of resistors you need to add to the motherboard to get it working?
you know I've been wondering about the feasibility of replacing the pismo motherboard, are there any motherboard manufacturers/designers that could design and build one?
you know I've been wondering about the feasibility of replacing the pismo motherboard, are there any motherboard manufacturers/designers that could design and build one?
it would be rather expensive
But damn cool.
I'm betting its possible to hire someone to engineer a replacement motherboard for the pismo, believe it would just require taking a newer macbook pro motherboard and re-designing it in pismo motherboard form factor (with a few tweeks). Anybody have an idea on cost, companies that have expertise, etc?
i know of a few car forums that have group buys on limited run custom made parts for their cars if no one makes what they want for their cars. this is a long and sometimes painful process and sometimes turns up empty handed. i know you have to have so many people interested in the part if it was to be made, you have to pay in advance to the company making the part, the amount will be allot more (some time 2x - 3x more) then if the part was already in production. you then have to ship them the original part so they can make sure the new part will fit properly.
but for a computer mobo replacement the amount of people required and the amount of money each one will have to pay will be on the order of magnitude greater then a given part of a car. and the issue would be to track down the person or company that would do it.
Machining one-off car parts is quite a bit easier than creating multilayer custom PCBs, let alone reengineering one to fit another case. Creating a custom case part is much easier than a system board, too. There have been group buys for custom case parts, but I'm not really aware of anyone going in to have a full custom mobo made that wasn't a one-off prototype for an actual corporation.
yea i think as soon as someone would hear the price required to begin having something like this done would scare the person off quite fast, yea its not worth it in any way shape or form. if this was ever to happen (which it wont) and you put this into the pismo, it will no longer be a pismo. why not settle for a Macbook or Macbook Pro. you will be spending allot less money on it as well.
I'd be happy to do it for you. Get me the original schematics and board layout for the Mac Pro motherboard of choice, the complete bill of materials required, and all of the custom firmware that Apple wrote to glue it all together. Then give me a year and roughly $500k USD, plus materials, and I'll make it happen with a few of my coworkers.
Maybe.
Seriously, what you're asking is beyond any one person or small group outside of Apple. The amount of resources and money required are large. Just passing the FCC radiation tests costs upwards of $2k/day of test lab time, not including any modifications you have to make to keep your motherboard from interfering with your microwave, your clock radio, etc.
There's a reason you don't see anyone building their own PowerPC or x86 motherboards in their garages. It takes a huge amount of backing and impressive resources to make it happen. The software e-CAD package to do the memory trace routing alone is $20k per seat. The test equipment to monitor busses and debug chip-level communication is tens to hundreds of thousands of dollars per unit. To make a functional, producible, and reliable board is pretty much out of the question.
I'm not saying this to be a dick. I'm a hardware engineer that's actually worked on projects like these before. It's HARD.
Buy a MacBook. You'll be happier. I promise.
I never said I wanted to completely redesign a new one, and build it with all new parts, I was saying what if you take a motherboard from a MacBook and got a new blank PCB stamped out in the shape of the Pismo motherboard, then transfered all the components to the new board, in the same or similar pattern as the original Pismo board.
That can't happen.
"Stamping out" a new PCB is impossible. The PCB features, for example, between the northbridge chip and the memory, are VERY specifically tuned, and can't just be plopped on a new board. There WILL be development time. With the frequencies that modern processors run at, the length of PCB traces is critical, and tuning the interconnects is a very real part of the design process. I'd guess at least 100 hours of PCB design/layout time, assuming I had the schematics from Apple in a format I could import into the tools I use.
Additionally, the idea that you could just transfer the parts over like you can with Legos is laughable. Plan on the 20k+ BGA rework tools for something like that, just as a start. As above, there are a lot of tuning parts (skew mitigation inductors, filter capacitors, etc) that will be specific to an individual PCB layout.
But wheres the "Hacker" in buying just a plain old MacBook? If I had time or money to do this, I wouldn't care what it cost, I would just get it done. I believe that it will cost plenty, but it can be done.
Finagle yourself a chance on "Are you Smarter then a 5th Grader?" and win the full million and maybe you'll have the money. Whether a 5th Grader would be silly enough to blow a million dollars on upgrading a Pismo is another question, of course.
I have to admit I fail utterly to see the point of Pismo worship, myself. The only thing that makes it special is it's a Mac. In terms of form factor it's almost identical to a bog-standard Dell Latitude C or D-series. (Boring yet "practical" 14 inch clamshell with a swappable drive bay. Uhm... woot?) Plenty of PC manufacturers still make boring yet practical clamshells. Install OS X on one and you have your x86 Pismo upgrade. It's not legal but it's a heck of a lot cheaper.
--Peace
X2
Well, that's kinda the point. It's practical. The Pismo is the last "function over form" laptop that Apple made, and with the direction that their laptops have been going over the past few years, I don't see them going back and selling a true workhorse laptop.
A true work laptop does not need to be pretty. It does not need to be ultra thin and light. It needs to be rugged. It needs to be expandable. It should be easy to fix when things break. Apple's laptops have not met the "rugged" and "expandable" criteria for nearly a decade. I'm hanging on to my Pismo for a looong time.
That said, the idea of building a new motherboard with which to retrofit Pismos with is thoroughly ridiculous.