Mac-PPC users now have the option for soldered RAM upgrades.
In a fascinating development for vintage Apple enthusiasts, a renowned figure in the retrocomputing world, DosDude1, has devised a hack that enables soldered RAM upgrades for PowerPC Macintosh computers. This hack not only involves physically soldering additional RAM chips onto the motherboard but also modifying the machine's BootROM firmware to recognise the new RAM.
The process begins by identifying the BootROM's EEPROM chip on the motherboard and extracting its contents. A document called "Boot Flash System Configuration Block," discovered by LightBulbFun, provides invaluable insights into modifying specific HEX values in the BootROM dump. For instance, on an iBook G3, increasing the RAM from 1 to 2 soldered chips involves changing the HEX value at offset 0x5C from 0x01 to 0x02. This alteration informs the system to detect all newly soldered RAM chips on the board.
Once the BootROM is edited to reflect the new RAM configuration, the modified dump is flashed back into the EEPROM using a hardware programmer or via software tools like the flashrom command under Linux. This enables the PowerPC Mac to "know" about the new RAM and use it properly after rebooting.
However, it's essential to note that the RAM modules' footprints must match those on the PowerPC Macintosh, and the specs of the RAM modules must also align with those the PowerPC Macintosh was designed with. Additionally, increasing RAM density requires ensuring the board has spare address lines or a way to bodge them in.
Despite being old, PowerPC Macintosh computers already have more than 640 KB of memory, which is sufficient for most purposes. However, the addition of 128 MB RAM, as demonstrated by DosDude1 in his hack, can significantly improve the performance of these classic machines.
It's important to remember that this hack is not about adding extra gigabytes of DDR5 to a PowerPC Macintosh designed with OS9 in mind. Instead, it's a testament to the ingenuity of the retrocomputing community and their continuous efforts to extend the life and capabilities of these vintage machines.
The information about this groundbreaking hack was first shared on r/VintageApple on Reddit, further highlighting the vibrant and collaborative nature of the vintage Apple community. As always, it's recommended to approach such modifications with caution, ensuring a thorough understanding of the process and the necessary tools before proceeding.
[1] The original Reddit post can be found at: https://www.reddit.com/r/VintageApple/comments/x21336/dosdude1_just_released_a_soldered_ram_upgrade/ [3] More details about the hack can be found on DosDude1's website: https://dosdude1.com/2022/04/08/powerpc-ram-upgrades/
- Embracing the DIY culture in the home-and-garden of tech enthusiasts, this modern-day alchemy of upgrading RAM on PowerPC Macintosh computers has extended from the realms of cutting-edge technology and ventured into the hacking lifestyle, thanks to the pioneering work of DosDude1.
- Amid the tangible clashes of solder and hardware components, the fusion of knowledge from resources like the 'Boot Flash System Configuration Block' documented by LightBulbFun and software tools such as Linux's 'flashrom' command transforms once antiquated PowerPC Macs into more efficient, contemporary machines.
- Leveraging the collaborative spirit embodied in online communities like r/VintageApple, retrocomputing connoisseurs unite in pursuing unconventional methods to breathe new life into their vintage Apple devices, transcending the original design specifications and redefining the boundaries of what is possible in home-and-garden hardware projects.
