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#7470 Dodano: 10-06-2014 11:04. Głosów: 113
¯\(°_o)/¯ I DUNNO LOL:
I once worked at a place that had a custom message format for an embedded system. It used 0xFF to mark the start of fields in IPC messages, so 0xFF was not allowed in field data, because then you couldn't find the next field. (The protocol normally passed numbers as BCD.)
They also had a PoS system, with multiple DOS-based terminals (this was back in the '90s) connected via Ethernet. There was a message defined to announce the Ethernet address of the PoS system computers, and the last field in the message was the MAC address.
Except MAC addresses are binary, and may contain an 0xFF. But this was always the last field, always a specific message type, always a specific field ID, and only passed between the PCs, not the embedded system. They could have made it a special case.
Nope. What they did was every time they got a new Ethernet card, they checked its MAC address. If it contained an 0xFF, they threw it in the trash. I left before Ethernet ports started becoming standard on PC motherboards.
http://thedailywtf.com/Comments/Half-Credit.aspx#434605
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I once worked at a place that had a custom message format for an embedded system. It used 0xFF to mark the start of fields in IPC messages, so 0xFF was not allowed in field data, because then you couldn't find the next field. (The protocol normally passed numbers as BCD.)
They also had a PoS system, with multiple DOS-based terminals (this was back in the '90s) connected via Ethernet. There was a message defined to announce the Ethernet address of the PoS system computers, and the last field in the message was the MAC address.
Except MAC addresses are binary, and may contain an 0xFF. But this was always the last field, always a specific message type, always a specific field ID, and only passed between the PCs, not the embedded system. They could have made it a special case.
Nope. What they did was every time they got a new Ethernet card, they checked its MAC address. If it contained an 0xFF, they threw it in the trash. I left before Ethernet ports started becoming standard on PC motherboards.
http://thedailywtf.com/Comments/Half-Credit.aspx#434605