Looking for HP41CX Advice

[Monte Dalrymple]

(08-04-2021 08:00 PM)Neve Wrote:  

(08-04-2021 07:51 PM)Sylvain Cote Wrote:  41CL MMU configuration can changes startup and/or operation speed a lot.
The best way to validate startup speed is to deactivate the 41CL MMU and then do the comparison.
If you have similar speed, then you know that the slowness is coming from the ROM's that you have mapped on the 41CL.
Sylvain

As I wrote in my previous post, even with a MEMORY LOST, MMU CLEARED and disabled, TURBO 0, it’s still slower.
It’s hard to describe, but it looks like the display is popping up in a spongy way, or rather “fading in”, if that makes any sense; whereas the CX is almost instantaneously showing up.

I could almost describe it as a capacitor slowly charging up, whereas on the CX the charge seems instantaneous.

The YFNZ power-on polling point code is about 75 instructions, or roughly 12mS. The LCD bias voltages in the 41CL are generated using low-power op-amps (for source/sink operation) and I optimized for power consumption rather than speed. I suppose that it is possible that these bias voltages (1.1V and 2.2V) might be slower to reach their final values than in the original HP-41, but it's not something that I cared about or ever investigated.