Interesting point. Look for 16-bit "Configuration Register" (CFG) at physical address 0x25800000. Bit 3, ALCON, reflects the "Alternate Console" S3 switch, and is 1 when the serial console is to be used. See KA49 Processor Module Specification V 1.1, chapter 5.2. However, the CFG register is described as read-only!Anybody found this "KA49 Processor Module Specification V 1.1" online anywhere?
I'd like to find that, too, and/or any other specifics for the 4000/90 / 90a / 96. For starters, I'd LOVE to see NetBSD be able to report where ECC memory corrections occur, which would make diagnosing memory issues much easier. Likewise, when a machine check occurs, I'd love to know why...
John