On 2018-04-12 23:05, Mark Pizzolato wrote:
I've added this to the pdp11_rq.c to describe these values: /* MediaId Is defined in the MSCP Basic Disk Functions Manual, page 4-37 to 4-38: The media type identifier is a 32-bit number, and it's coded like this: The high 25 bits are 5 characters, each coded with 5 bits. The low 7 bits is a binary coded 2 digits. Looking at it, you have: D0,D1,A0,A1,A2,N For an RA81, it would be: D0,D1 is the preferred device type name for the unit. In our case, that would be "DU". A0,A1,A2 is the name of the media used on the unit. In our case "RA". N is the value of the two decimal digits, so 81 for this example. And for letters, the coding is that A=1, B=2 and so on. 0 means the character is not used. So, again, for an RA81, we would get: Decimal Values: 4, 21, 18, 1, 0, 81 Hex Values: 4, 15, 12, 1, 0, 51 Binary Values: 00100, 10101, 10010, 00001, 00000, 1010001 Hex 4 bit Nibbles: 2 5 6 4 1 0 5 1 The 32bit value of RA81_MED is 0x25641051 */ Thanks.
No problem. And thanks for clearing up my scribblings. I feared that it might have been a bit too cryptic.
I'm wondering if the leading first two characters (DU) of the ID is used when a device is "MSCP Served" by one system out to a cluster at large. This might facilitate connecting the serving system's local driver to the remote requests.
No idea, but it's definitely possible. Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: b...@softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh