[Simh] Disk info request

[Rich Alderson]

> From: Timothe Litt <litt at ieee.org>
> Date: Tue, 8 Mar 2016 20:47:45 -0500

> Below is a list of all the disks that have been used with FILES-11 (ODS2) for
> which I have reliable (I think) data.

> The list has blank spots for a lot of disks that I know exist, but for which I
> don't have reliable data.

> Name     SecSiz Sec/Tk Tk/Cy Cyls   Capacity       LBNs               Delta
> *RA80     ----- ------ ----- ----- ---------- ---------- ----------
> *RA81     ----- ------ ----- ----- ---------- ---------- ----------
>  RA82       512     57    15  1435  628185600    1226925    599.084 MB   913

I can provide some information about the hardware values, based on the table at
Phil Budne's site (http://www.ultimate.com/phil/pdp10/dec.disks).

The RA80 has 31 sectors/track, 14 tracks/cylinder, and 546 cylinders.  On the
PDP-10, this gets you 124MB in 576-byte sectors.

The RA81 has 51 sectors/track, 14 tracks/cylinder, and 1248 cylinders.  This
gets you 446MB.

For comparison, the RA82 is listed as providing 608MB in 1423 cylinders, so the
PDP-10 habit of not using all the cylinders on a pack or HDA appears to hold
true for the MSCP disks as well.

Not exactly what Tim was looking for, but useful for comparison, I should think.

                                                                Rich