A closeup of the constant ROM showing the silicon and polysilicon. This ROM is mostly a grid, but the transistors are somewhat distorted and the grid is squished a bit to take advantage of empty space.

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1. Ken Shirriff (kenshirriff@oldbytes.space)'s status on Sunday, 15-Jan-2023 04:14:41 JST Ken Shirriff

   in reply to

   Other ROMs, such as this constant ROM, are not exactly a grid but are slightly optimized: the transistors are somewhat distorted and the grid is squished a bit to take advantage of empty space.
   It's not clear if these potential transistors should be counted since there might not be room to fill in all of them. Also, some transistors act as diodes and many act as pull-up resistors.