Sharp PC-E500 Turbo mode?

[toml_12953]

On the N-Queens benchmark website

https://www.hpmuseum.org/cgi-sys/cgiwrap...i?read=700

It shows some Sharp PC-E500S runtimes with Turbo listed after the time (BASIC / Turbo x2.1) It looks like there's a turbo mode available. Does anyone know how to activate it?

[Bushcat]

Do you mean a hardware clock upgrade? That requires two components: swap out the existing Ceralock for a 4.8 MHz Ceralock; replace the existing 180k resistor with a 68k resistor. There's a diagram somewhere showing how to put the Ceralock in parallel with the existing one, using a small switch to flip between them.

If there's "turbo" setting or software, then I'm barking up the wrong tree so ignore me :-)

[xerxes]

"Turbo" means acceleration by hardware modification and "Fast Mode" by software control. If a ceramic resonator is used, it's normally enough to just replace it.

[Bushcat]

(07-20-2023 06:09 AM)xerxes Wrote:  "Turbo" means acceleration by hardware modification and "Fast Mode" by software control. If a ceramic resonator is used, it's normally enough to just replace it.

Going back decades here when information was in magazines rather than on the internet, I dimly remember that the 68k resistor added in the modification would work with the new and old ceralocks, but the original 180k resistor would not work with the new ceralock. If you know differently, that's one fewer components to swap out :-)

[xerxes]

I've modified many calculators and in all cases it was only necessary to replace the ceralock.

[robve]

(07-23-2023 05:13 PM)xerxes Wrote:  I've modified many calculators and in all cases it was only necessary to replace the ceralock.

Just curious, but wouldn't this mod disable the serial interface and printer/cassette port, and make the sound output pitch high? If that is the case, the only way to load and use programs is to copy them to the RAM card.

Talking about modding the PC-E500S. I own a 32KB and a 256KB E500S with additional RAM installed. I wonder if there is any documentation online or in old magazines how this RAM mod can be made?

- Rob

[toml_12953]

(07-23-2023 08:54 PM)robve Wrote:  

(07-23-2023 05:13 PM)xerxes Wrote:  I've modified many calculators and in all cases it was only necessary to replace the ceralock.

Just curious, but wouldn't this mod disable the serial interface and printer/cassette port, and make the sound output pitch high? If that is the case, the only way to load and use programs is to copy them to the RAM card.

Talking about modding the PC-E500S. I own a 32KB and a 256KB E500S with additional RAM installed. I wonder if there is any documentation online or in old magazines how this RAM mod can be made?

- Rob

This might help you:

https://github.com/cazacov/PocketCompute...AM-upgrade

[xerxes]

(07-23-2023 08:54 PM)robve Wrote:  Just curious, but wouldn't this mod disable the serial interface and printer/cassette port, and make the sound output pitch high? If that is the case, the only way to load and use programs is to copy them to the RAM card.

I would recommend to use 4.6 instead of 4.8 MHz, to be able to use the serial interface using the half baud rate. The sound pitch is higher and the printer/cassette port is disabled.