Uploaded October 2025 | Updated September 2026, 1 week ago
The Quadra 700 was made famous by the movie Jurassic Park - it was Dennis Nedry's development computer. And keeping with the spirit of the movie ("spared no expense"), I think my Quadra 700CD should have a full complement of VRAM.
And you might think that I'd go to eBay (the place where I buy the things I later regret™) to buy three pairs of 256K VRAM SIMMs... but eBay prices for VRAM SIMMs are not predictable. Plus, single 512K VRAM SIMMs are more common for some reason; they would work but half of the memory would go unused. So I did the next best thing: I found the memory chips needed to build 256K VRAM SIMMs. On eBay, of course.
I'vs ordered PCBs, capacitors, and solder paste, so it's time to build a set of VRAM SIMMs. My PCBs are based on Garrett's Workshop's design (github.com/garrettsworkshop/MacVRAMSIMM) - special thanks to Zane Kaminski for open sourcing the design!
Did I make mistakes while ordering parts? Will the assembled VRAM SIMMs work? Will I regret buying those memory chips instead of VRAM SIMMs? You'll have to watch to find out!
*
Ways to Support the Channel:
☕️ Tips or Support via Ko-fi: ko-fi.com/jdmcs
🈷️ Support me on Patreon: patreon.com/jdmcs
📦 Amazon Wishlist: jdmcs.net/wishlist
... or simply do the YouTube things: Like/Dislike, Comment, Subscribe, Enable Notifications, and participate in the Chat. These things help the channel, too!
**
Read Computerized Start™, my Official Blog: jdmcs.net/myblog
Follow me on Instagram: jdmcs.net/myinstagram
Follow me on Twitter: jdmcs.net/mytwitter
The Quadra 700 was made famous by the movie Jurassic Park - it was Dennis Nedry's development computer. And keeping with the spirit of the movie ("spared no expense"), I think my Quadra 700CD should have a full complement of VRAM.
And you might think that I'd go to eBay (the place where I buy the things I later regret™) to buy three pairs of 256K VRAM SIMMs... but eBay prices for VRAM SIMMs are not predictable. Plus, single 512K VRAM SIMMs are more common for some reason; they would work but half of the memory would go unused. So I did the next best thing: I found the memory chips needed to build 256K VRAM SIMMs. On eBay, of course.
I'vs ordered PCBs, capacitors, and solder paste, so it's time to build a set of VRAM SIMMs. My PCBs are based on Garrett's Workshop's design (github.com/garrettsworkshop/MacVRAMSIMM) - special thanks to Zane Kaminski for open sourcing the design!
Did I make mistakes while ordering parts? Will the assembled VRAM SIMMs work? Will I regret buying those memory chips instead of VRAM SIMMs? You'll have to watch to find out!
*
Ways to Support the Channel:
☕️ Tips or Support via Ko-fi: ko-fi.com/jdmcs
🈷️ Support me on Patreon: patreon.com/jdmcs
📦 Amazon Wishlist: jdmcs.net/wishlist
... or simply do the YouTube things: Like/Dislike, Comment, Subscribe, Enable Notifications, and participate in the Chat. These things help the channel, too!
**
Read Computerized Start™, my Official Blog: jdmcs.net/myblog
Follow me on Instagram: jdmcs.net/myinstagram
Follow me on Twitter: jdmcs.net/mytwitter
![The Apple ][ Plus Clone: The Desolation of Sockets... as I Attempt Repair (Computerized Start™ Live)](https://i.ytimg.com/vi/BkyfY4LIXzg/mqdefault.jpg "The Apple ][ Plus Clone: The Desolation of Sockets... as I Attempt Repair (Computerized Start™ Live)
Ive launched a merch shop: https://shop.jdmcs.com - use code JUSTINTIME for 5% off all Computerized Start™ merchandise through at least June 30th!
*
I bought an Apple IIe Clone Motherboard on eBay (the place where I buy the things I later regret™) knowing full well it was an Apple ][ Plus clone motherboard and missing some chips. Yes, COMPUTER was jealous at first, but then COMPUTER realized I needed practice on a similar motherboard before I continue removing sockets, so were good...
Last time I worked on this board, I replaced enough capacitors to satisfy my concern that there wasnt enough capacitance on the board for proper operation. I was able to confirm the original 6502 was working by swapping it into my Apple ][ Plus. I also removed a few sockets that looked like they had too much solder. Still, the board powers up to garbage. I resigned to ponder the schematic.
Tonight, I am going to replace the rest of the capacitors, then I will commence The Desolation of Sockets. I have identified a few components that could prevent the CPU from running code, and I will be removing sockets for those components if they look questionable underneath. Well go from there.
Will I find issues under sockets? Will I get the board to do something by the end of the stream? Youll have to watch to find out!
*
Ways to Support the Channel:
☕️ Tips or Support via Ko-fi: https://ko-fi.com/jdmcs
🈷️ Support me on Patreon: https://www.patreon.com/jdmcs
📦 Amazon Wishlist: https://jdmcs.net/wishlist
... or simply do the YouTube things: Like/Dislike, Comment, Subscribe, Enable Notifications, and participate in the Chat. These things help the channel, too!
**
Read Computerized Start™, my Official Blog: https://jdmcs.net/myblog
Follow me on Instagram: https://jdmcs.net/myinstagram
Follow me on Twitter: https://jdmcs.net/mytwitter")
