I am starting a thread over here, so that Powermax and I stop hijacking the "Q700 ADB or board kaput" thread.
This thread is for discussion of topics related to recreating the CUDA and/or EGRET chips from non-Apple hardware. The chips are based on the Motorola 68HC05 microcontroller according to notes from Apple, so in theory, what is needed is to download the ROM code from an existing chip, program it into the ROM of a new (old stock) 68HC05 chip and proceed.
There may have been variations in the 68HC05 such as package, pinout, amount of RAM or ROM onboard, etc. that make this more complicated. I haven't checked the relevant datasheets yet.
There are various versions of the chip used by Apple, so different versions may be needed on different machines. I can report that I've taken a 341S0060 and installed it into a machine that formerly had a 341S0788 and the machine operated properly afterwards. Possibly there was some obscure issue that I never ran into, but as far as I can tell, it worked perfectly.
Powermax reports that the CUDA was based on the Motorola 68HC05EG, which may be similar to the 68HC05E1. Datasheet here HC05E1GRS.pdf
There is a tool for making CUDA dumps, so it should be possible if a compatible 68HC05 can be found, to program the code into a new chip and substitute it into a needy Mac, without scavenging from an old board. http://www.gryphel.com/c/minivmac/extras/egretrom/index.html
This thread is for discussion of topics related to recreating the CUDA and/or EGRET chips from non-Apple hardware. The chips are based on the Motorola 68HC05 microcontroller according to notes from Apple, so in theory, what is needed is to download the ROM code from an existing chip, program it into the ROM of a new (old stock) 68HC05 chip and proceed.
There may have been variations in the 68HC05 such as package, pinout, amount of RAM or ROM onboard, etc. that make this more complicated. I haven't checked the relevant datasheets yet.
There are various versions of the chip used by Apple, so different versions may be needed on different machines. I can report that I've taken a 341S0060 and installed it into a machine that formerly had a 341S0788 and the machine operated properly afterwards. Possibly there was some obscure issue that I never ran into, but as far as I can tell, it worked perfectly.
Powermax reports that the CUDA was based on the Motorola 68HC05EG, which may be similar to the 68HC05E1. Datasheet here HC05E1GRS.pdf
There is a tool for making CUDA dumps, so it should be possible if a compatible 68HC05 can be found, to program the code into a new chip and substitute it into a needy Mac, without scavenging from an old board. http://www.gryphel.com/c/minivmac/extras/egretrom/index.html
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