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XTIDE on 3Com Etherlink II card, anyone have this working?

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new_castle_j

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Has anyone gotten the XTIDE Bios to work in the ROM socket of a 3Com Etherlink II TP 3C503?

I burned the ide_at.bin from XTIDE Universal BIOS v2.0.0 beta 3 into a 2764 EPROM and set the jumper on the 3Com card to enable the ROM socket at DC000. I put the card into the 8bit ISA slot of my 386 Toshiba T3200 SXC, and I'm not seeing a BIOS message from the XTIDE ROM. The system boots to DOS on the floppy and I can run the 3C503.exe diagnostic program.

I saw in the manual that the default location for the XTIDE bios is D000, is that why I'm not seeing the XTIDE BIOS message?
 
I usually use C800, D000 etc - maybe the Toshiba isn't looking for extension ROMs at DC00?
I often use it in network cards, and have tested it on a Toshiba T3200SX (not an SXC, but close enough) - works even in the 8 bit slot.

I'd also do some double checking too e.g. none of the pins on the 2764 got bent underneath the chip when it was inserted, that it's configured correctly (e.g. enabled + 8KB/2764), and that the contents of the EPROM are correct.
 
The 3Com 3C503 is "special", it returns 8080h as the last two bytes of the 8 KB ROM and this hides the option ROM checksum byte. I added a quick workaround for this to the build checksumming script in the latest revision but that will only work as long as no changes are made with XTIDECFG. The proper fix would be to add the workaround to XTIDECFG as well but that's a bit more involved.

Anyhow, it will work if you manually move the checksum byte (the last byte) so it is the third byte from the end.
 
Wow, thanks for the direction. I see the relevant section of code in the checksum.py script. I wouldn't have figured this out on my own. I will erase my EPROM and try again with the advice you have provided. Thanks Much!
 
Success!!! Thanks again. After loading the .bin file into my Eprom burning software, I edited the last few bytes and moved the checksum over 2 places, then burned the image. The Etherlink II 3C503 now recognizes XTIDE and enables my 8GB solid state drive. Very Cool!
 
Krille said:
The 3Com 3C503 is "special", it returns 8080h as the last two bytes of the 8 KB ROM and this hides the option ROM checksum byte. I added a quick workaround for this to the build checksumming script in the latest revision but that will only work as long as no changes are made with XTIDECFG. The proper fix would be to add the workaround to XTIDECFG as well but that's a bit more involved.

Anyhow, it will work if you manually move the checksum byte (the last byte) so it is the third byte from the end.
Click to expand...
@Krille sorry to invoke a 9 year old thread but Krille can you expand on this as it applies to the XTIDE universal bios today? I have the same 3Com Etherlink II TP 3C503 as @new_castle_j and have spent the past few hours trying to get xtide universal bios working on this network card. Also I realize I cannot use a ROM larger than a 27c64 for some reason as it only allocates 8KB
 
Yeah, this problem was fixed a long time ago. Any build that is 8 KB (official or custom) includes the fix so if you're still having problems then it must be something else.
 
Krille said:
Yeah, this problem was fixed a long time ago. Any build that is 8 KB (official or custom) includes the fix so if you're still having problems then it must be something else.
Click to expand...
You are right. I ended up using my Lo-tech ROM card to figure out the memory issues with the XTIDECFG program and I was able to make the rom and burn it to the Etherlink II TP. Its working great now. Thanks for clarifying the issue @Krille
 
I always find it hilarious when someone else has the exact same issue that I've now run into... A T3200SXC with a 3Com 3C503 card that won't boot XT-IDE. Thanks to all the information above, I also got it working, but not quite the same!
My card was reporting 0x04 0x04 at the end, instead of 0x80 0x80. I used a different checksum editor and then manipulated the difference into the third-last byte.
Again, thanks all for the invaluable information above!
More information here for anyone else dealing with boot PROMs in the 3Com 3c503: https://modelrail.otenko.com/retro/3com-etherlink-ii-3c503-boot-roms
 
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