FX-9860 GII system error when launching G1As

[wisemoth Profile]

Hello

I've just got a new fx-9860 GII, running OS 02.09.0201. I've got a few G1As that are running OK in the emulator (eg Gravity Duck, and Periodic Table) but fail to start when I've sent them over FA-124. Each appears with their correct icon in the menu, but when I launch them I get "System ERROR". I've also got FTune, and that actually works fine on the calculator.

I'm I doing something wrong?

Thanks for any advice!

[wisemoth Profile]

I should say my current guess is that it relates to the GII being an SH4 processor and the failing apps may have been coded for the original G/SH3 ?

I'd also rebuilt locally the Gravity Duck from source, which still fails. I suppose the new OS requires source changes rather than just a binary rebuild (changed syscalls ?) ?

[SimonLothar]

Yes. There are a few syscalls, which are no longer supported with newer OSes (f. i. MMU syscalls).
Syscall 0x42E (Bfile_GetMediaFree_OS) is sometimes the reason for problems.
Some older addins bypass syscalls. The use of absolute addresses or direct register accesses usually leads to incompatible programs someday.

You have to inspect the source to find the problem.
Modify the source to encircle the cause of the error.

In Gravity Duck I suspect

unsigned char key_down(unsigned char code)

in key.c. It uses register addresses, which are not compatible with the SH7305.

[SimonLothar]

Another issue in Gravity Duck's time.c:

Code: Select all

#include "time.h"

static int SysCallCode[] = {0xD201422B,0x60F20000,0x80010070};
static int (*SysCall)( int R4, int R5, int R6, int R7, int FNo ) = (void*)&SysCallCode;
int time_getTicks()
{
   return (*SysCall)(0, 0, 0, 0, 0x3B);
}


static int SysCallCode[] = {0xD201422B,0x60F20000,0x80010070};
must be replaced by
const int SysCallCode[] = {0xD201422B,0x60F20000,0x80010070};

It is not possible to run code out of RAM using virtual addresses with the newer machines.

Key.c and MonochromeLib.c are affected, too.

[SimonLothar]

I also replaced key_down (in key.c) with

Code: Select all

unsigned char key_down(unsigned char code)
{
short keycode;
   keycode = ( ( code & 0xF0 ) << 4 ) | ( code & 0x0F );
   return (*SysCall)((int)&keycode, 0, 0, 0, 0x24A);
}


So far Gravity Duck runs without detectable errors.

[wisemoth Profile]

Thanks so much Simon, much appreciated! I'll give that a go.

[SimonLothar]

Alas, syscall 0x24A is no longer compatible between SH-3- and SH-4A-systems. Hence the SH-4A version would not work with SH-3 machines.
Above that syscall 024A is not able to detect more than one key hit at a time. Possibly this could be a problem with the difficult parts of the game.
So I provided for some different approach:
http://www.casiopeia.net/forum/download ... &df_id=157
G1A and changed source files are included.

[wisemoth Profile]

Many thanks Simon - that's most interesting.