BBA EEPROM
Another quick entry. While working on the Realtek RTL 8139C’s interface, I wondered what the EEPROM contained in case there was anything that could be used (and in case it goes bad over time).
If it’s useful to anyone else, this is what I did to get the contents of the EEPROM.
- Locate the chip marked as M93C [U3] on the board
- Mask off the surrounding area with polyimide tape
- Apply flux and new solder to the chip (not necessary, but it’s a habit)
- Heat with a hot air rework station until the chip could be removed
- Clean off any remaining solder with solder wick
- Clamp it into a SOIC-8 adapter (labelled as SOP8 150mm for me) for the TL866II Plus (or other similar EEPROM programmer)
- Read the contents of the chip (noted below)
- Solder it back and test it’s working
![marked as M93C [U3] on the board](https://commons.wikimedia.org/wiki/Category:Sega_Dreamcast_Adapter#/media/File:Sega-Dreamcast-Broadband-Adapter-Motherboard-T.jpg){kind=link}
For the dumping process, I used the minipro program.
This is the command to perform the dump. It does need to be read as 16-bit.
$ minipro -p "M93C46R(x16)@SOIC8" -r bba_nand.binAfterward, the file should contain the following (except that bytes 0x0E-0x13 should contain the MAC):
00 2981 DB11 3412 0000 0000 2020 1240 00D0
10 F103 2521 101C 0000 0080 B943 F2B0 1A04
20 43DF 368A 43DF 368A B943 F2B0 1111 1111
30 0000 0000 0000 0000 0000 0000 0000 0000
40 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF
50 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF
60 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF
70 FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFFFor convenience, this is the content as a file. If the chip goes bad, a replacement shouldn’t be too hard to find. Just remember to replace the MAC with the one on the Broadband Adapter’s sticker.