Checksum fail. ROM not signed for BIOS

[petran79]

Some rom files give me this message and funny thing is this happen even when I load the BIOS file!

d:\emulators\atari7800>D:\emulators\atari7800\test7800_windows_amd64_terminal.exe
Flat cartridge from [BIOS] Atari 7800 (USA).a78
console reset
16k NTSC BIOS at 0xf000
PC=f884 A=b1 X=37 Y=14 SP=7e SR=sv-BDIzC
emulation running
most recent CPU instructions
$232a beq $d4
$232c lda $fff8
$232f ora #$fe
$2331 cmp #$ff
$2333 bne $ce
$2335 lda $fff8
$2338 eor #$f0
$233a and #$f0
$233c bne $c5
$2303 jmp $26c2
PC=26c2 A=d0 X=ff Y=7f SP=ff SR=Sv-BdIzC
117942 instructions in 0.38 seconds
checksum fail. ROM not signed for BIOS

[JetSetIlly]

I suspect those ROMs have not be signed. Part of the build process of a game is to use the 7800sign tool but that's not always done.

There are three ways to run a non-signed ROM:

1. Run without the BIOS at all. Run with the command line option -bios=false
2. Interrupt the BIOS and route it around its checksum code. Run with the command line option -checksum=false
3. Run with the PAL BIOS. Command line option -spec=PAL

Option 3 is obviously a poor solution if you want to run an NTSC ROM. Option 2 is probably the best solution overall. In fact, making -cheksum=false the default might be a good the thing to do. @trebor68 What do you think about that?

[trebor68]

The workaround is good, but any using the emulator for development may be misled. Typically, if an NTSC ROM is not signed, there are often other thing wrong with it such as bad header information. Granted, there may be bad header information provided for a PAL ROM too, but properly signed NTSC ROMs and proper headered ROMs are essential for avoiding inaccurate 'bug' reports.

@petran79 if this is not a ROM for a game your developing, and rather just looking to run an already existing title have your tried utilizing the 7800 ROM PROPack? https://7800.8bitdev.org/index.php/Trebors_7800_ROM_PROPack

The set contains all publicly available ROMs with signatures and headers.

<edited by mistake - I didn't realise I could do that>

[JetSetIlly]

.The workaround is good, but any using the emulator for development may be misled.

I agree. Until I add a UI to enable more immediate feedback the current defaults are good