There was a 603ePPC Upgrade for the 500 series, but I do not know of that was a logic board upgrade or a processor swap. I believe it was a CPU Card swap.
Now this got me thinking. The 1400 CPUs are on a card as well, as well as the ROMs, I believe. As are other CPUs on a card, also contain their on ROMS. The problem where is being the compatibility of the 1400CU Card to the CPU Card connector on the 500 Motherboard. If it fits and is compatible, it could solve a lot of problems with the PCMCIA Booting on the 540. But would it accept the way the 500 has their PCMCIA set up? In the 1400, the PCMCIA is tied to the CPU through a buffering chip, not a through translator.
Again, it depends of it fits and if it is compatible. Unfortunately, the 190/5300/2300 has their CPUs on the motherboard. and not on a card. If it were on a card, I would think it would be ore compatible with the 500 series. Alas it never happened that way. This would undertake a lot of research before applying such a theory to work. And if it does work, it would no longer be a 500 series, but a 1400 series in a 500 series case.
Now this got me thinking. The 1400 CPUs are on a card as well, as well as the ROMs, I believe. As are other CPUs on a card, also contain their on ROMS. The problem where is being the compatibility of the 1400CU Card to the CPU Card connector on the 500 Motherboard. If it fits and is compatible, it could solve a lot of problems with the PCMCIA Booting on the 540. But would it accept the way the 500 has their PCMCIA set up? In the 1400, the PCMCIA is tied to the CPU through a buffering chip, not a through translator.
Again, it depends of it fits and if it is compatible. Unfortunately, the 190/5300/2300 has their CPUs on the motherboard. and not on a card. If it were on a card, I would think it would be ore compatible with the 500 series. Alas it never happened that way. This would undertake a lot of research before applying such a theory to work. And if it does work, it would no longer be a 500 series, but a 1400 series in a 500 series case.