Controller input

[Tidus79001]

Is any sort of alternate method of controller IO possible with the Atari 7800 that doesn't access RIOT? Just seems to me that the speed of 1.79 MHz speed is mostly unusable since naturally controller input is going to account for a lot of the processing. Could an alternate input method for controller input be achieved through some of of device designed to interface controllers using the expansion port? Just a horrible design that the 7800 is crippled by being forced to use RIOT since this drops the speed to 1.19 MHz for controller IO and makes this unavoidable if RIOT is the only method. At least for sound if you used Pokey you don't have to touch the TIA and drop the CPU speed. Would be nice to keep the CPU running at it full 1.79 MHz speed at all time.

[kskunk]

The actual slowdown is so brief it's negligible. To stay at 1.19MHz, you'd need to access RIOT on every cycle.

In practice, a single RIOT access costs just 0.5 cycles and reads both joysticks at once.

Controller logic is usually hundreds to thousands of cycles. (And involves TIA too.)

So, bypassing RIOT could not even save 0.1% in a typical game.

Hope that helps!