HP Forums
casio fx-cg10 topless! - Printable Version

+- HP Forums (https://archived.hpcalc.org/museumforum)
+-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html)
+--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html)
+--- Thread: casio fx-cg10 topless! (/thread-182568.html)

casio fx-cg10 topless! - hugh steers - 04-18-2011

off topic for HP, but some of you might be interested. here's a pic of the circuit board from the casio fx-cg10. im assuming the large blob is the processor (SH3) and the others are flash and ram?

i've been trying to find out how much ram it actually has. i know it's more than the official 64k. im thinking it might be 512k.


Re: casio fx-cg10 topless! - Eric Smith - 04-18-2011

Seems more likely to be 256KB. They need 165,888 bytes for the frame buffer, if they aren't using a CLUT (color lookup table).

Note that the flash chip shown is 32MB, so they must be reserving half of it for the firmware and other system use.

Edited: 18 Apr 2011, 6:08 p.m.

Re: casio fx-cg10 topless! - hugh steers - 04-18-2011

i know that the screen is 162k at 16bpp. im told that the system needs to buffer a copy of the screen. this would require 324k and therefore more than 256, if true.

with a lot of help, i've managed to get some native code running on it. i'll have to write some hacks to explore the ram limits.

i took the back off, incase it was obvious from the board, but the blob attack has thwarted me.

Edited: 18 Apr 2011, 6:57 p.m.

Re: casio fx-cg10 topless! - Eric Smith - 04-18-2011

A screen buffer, sure. The hardware reads the buffer, serializes the data, and presents it to the display drivers. But there's no good reason for a product like this to have TWO screen buffers unless they are doing some major animation. For small animations, they can simply update the relevant portions of the buffer during retrace time.

Good job getting native code running! It will be interesting to hear what else you discover.

Re: casio fx-cg10 topless! - hugh steers - 04-19-2011

i can't claim any credit for getting the native code running. i got all the help from the casio hackers. but im hoping to port some of my graphical stuff to it. that's why im interested in the ram and the screen layout.