Overview of Different Checksum Errors

[Gitweazle]

One problem with trying to solve the checksum errors is that there are different kinds. I thought I would list all variants and maybe we can figure out which connection problem belongs to which error:

>>Checksum Error<<

1. CHECKSUM ERROR: 55 != 190 memory/:maincpu/0/007e0000-007fffff (index: 23)

2. CHECKSUM ERROR: 73 != 70 memory/:eeprom/0/00000000-0000ffff (index: 39)

3. CHECKSUM ERROR: 189 != 191 SNES Cart (LoROM)/:snsslot:lorom/0/m_nvram (index: 769)

4. CHECKSUM ERROR: 82 != 188 palette/:palette/0/m_save_pen (index: 212)

5. CHECKSUM ERROR: 228 != 129 timer/timer_callback_a/0/m_start.attoseconds (index: 1717)

6. CHECKSUM ERROR: 93 != 250 timer/:ymsnd/0/0/m_start.attoseconds (index: 717)

7. CHECKSUM ERROR: 168 != 172 Z80/:maincpu/0/m_r (index: 51)

8. CHECKSUM ERROR: 116 != 118 global/0/m_watchdog_counter (index: 40)

9. CHECKSUM ERROR: 189 != 110 stream/2/0/msamplerate (index: 751)

10. CHECKSUM ERROR: 239 != 44 DISCRETE/:konami/40000140/m_output (index: 451)

>>Problem and Solution<< A) NVRAM does not match. Solution: Delete the respective NVRAM files.

B) CFG does not match. Solution: Delete the respective CFG files.

C) Despite the fact that we are using official MESS XMLs, MAMEHub can still detect SNES .SFC files. When a user tries to connect with such a file it will give a Checksum Error. Solution: Replace the SFC file with a shortname.ZIP file continaing the SFC.

D) Caused by changing sample rate in UME.ini (default 48000)

E) Linux users cannot connect or be connected to on certain Arcade systems (#311). Other games work fine. Solution: unknown.

[Gitweazle]

In this post I will link the Checksum Errors to a Problem & Solution. I will continue to add more as soon as I have tested and confirmed them.

(1,4) is caused by (B) (2) is caused by (A) (3) is caused by (C) (5,9,10) are caused by (D)

[Prinygod]

it might be helpful for user usability if some known problems could populate a pop up saying what the fix would be.

[Gitweazle]

I can't get anyone to connect to me in Raiden Fighters (rdftu.zip). You need an NVRAM to circumvent to 999 second boot up, but when I send the NVRAM to the other person they can't connect.

And now something new: Even when both parties (all Windows users) delete their NVRAM and CFG we still get a checksum error. It looks like it syncs, but then it suddenly kicks you out anyway at the very last moment.

Log of 2 people connecting to me: Link 1 Log of me connecting to somebody else: Link 2

[Gitweazle]

I had a look in the MAME source code and found out that (5) and (6) have something to do with sound of the Yamaha YM2151 chip. I thought sound sync was removed in a recent patch, so why is it giving such a checksum error?

[MisterTea]

Do you have multi threading turned off?

On Friday, November 21, 2014, Gitweazle [email protected] wrote:

I had a look in the MAME source code and found out that (5) and (6) have something to do with sound of the Yamaha YM2151 chip. I thought sound sync was removed in a recent patch, so why is it giving such a checksum error?

— Reply to this email directly or view it on GitHub https://github.com/MisterTea/MAMEHub/issues/281#issuecomment-63997104.

[Gitweazle]

Yeah I believe so:

UME.ini multithreading 0

So could this checksum error mean the other person has multi-threading on?

They all seem to be 'timing' mismatches, (5), (6) and (3) = watchdog timer.

[Gitweazle]

New checksum error discovered, which also has to do with sound/clock/timer. The user could not connect to others and I couldn't connect to him.

CHECKSUM ERROR: 63 != 236 stream/2/0/m_sample_rate (index: 801)

EDIT: User had an older version of MAMEHub.