[HECnet] RSTS/E under simh

[Johnny Billquist]

On 2014-05-15 23:56, Dave McGuire wrote:
On 05/15/2014 05:48 PM, Cory Smelosky wrote:
I need the /physical/ drive size! Different systems give me different
sizes.

  This, of course, should not happen.   The host should query the drive
for its size, in blocks...I don't know why a given host OS would give
you different numbers.

It is listed as 2G...the MicroVAX 3100 I wrote it with claims it's ~570M

    If it's an early MicroVAX-3100, and you're frobbing that drive via its
ROM-based monitor, that code is limited to 21-bit block numbers.   Later
machines use 32-bit block numbers.

And of course, as soon as you have booted, the driver of the OS is used instead, and all I know of use 32-bit block numbers at that point, so this limitation is only really relevant during booting, and not running.

(And if you can guarantee that all operations in the boot stage hits the first 2G of the disk, it works fine to boot from larger disks on a 3100 as well.)

	Johnny

-- 
Johnny Billquist                                   || "I'm on a bus
                                                                  ||   on a psychedelic trip
email: bqt at softjar.se                         ||   Reading murder books
pdp is alive!                                         ||   tryin' to stay hip" - B. Idol