Going forward to go backwards—65 program navigation

[teenix]

There was probably a budget allowance for the model and I imagine the code that was written for the 65 was as compact as possible so that it would fit in some allowed amount of expensive ROM space.

Every program word was used in the 12 pages of ROM in the 65, which in itself is amazing. (A page being 256 words). Who would strive to do that these days?

Adding these features would have had to increase the ROM page count to 16, assuming that 4 pages of ROM per IC package were available. Great if you want to add more functions, but there has to be a limit and large amounts of vacant ROM space would be a no no.

Space for an extra ROM chip on the CPU board would also be a problem.

cheers

Tony