[Simh] Fwd: SimH, PDP8 OS/8 and RKLFMT hang

[Mark Pizzolato - Info Comm]

On Thursday, March 14, 2013 at 11:24 AM, Al Kossow wrote:
> forwarded from the classiccmp mailing list
> 
> 
> -------- Original Message --------
> Subject: SimH, PDP8 OS/8 and RKLFMT hang
> Date: Thu, 14 Mar 2013 11:03:47 -0700
> From: Rick Bensene <rickb at bensene.com>
> Reply-To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> 
> I'm running SimH V3.9 on a PC under Windows 7  using the binaries from the
> primary SimH website.
> I'm running the OS8 distribution on floppy that is packaged on the Simh site.
> I attached an 'empty' RK disk drive file as RK0, and tried to run RKLFMT on it
> to "format" the drive.
> The RKLFMT program asks its questions (which drives to format), then says
> "ARE YOU SURE?" and expects a Y or N.  If N is typed, the questions about
> which drives to format are repeated.  If Y is typed, the formatting process
> begins.
> 
> On real PDP8/e hardware, it all does what it is supposed to...the drive does a
> bunch of writes, then goes back and reads the sectors to verify that they
> were written correctly, then prints out a message indicating that the format
> passes are complete, and then starts over with the "which disks to format"
> question, at which point you can type ^C to exit.
> 
> However, in SimH, the program starts up and asks which drives to format,
> and I say "Y" to drive 0, and "N" to the other 7 drives, then the "ARE YOU
> SURE?" prompt comes up, and I type "Y", and the Y echoes back, and then  it
> just sits there.
> On real hardware, it takes about 80 seconds to format a drive.  I waited
> MUCH longer than this to see if the simulated RKLFMT would eventually
> come back indicating that it had completed.  It didn't.

Hi Rick,

Great description.  100% reproducible.

The issue was that the initial RK disk operation was completing too quickly.  Changing RK_MIN from 10 to 45 allows things to work as expected.

The problem is fixed in the latest source at https://github.com/simh/simh/archive/master.zip

Pre Compiled binaries are available at:  https://github.com/simh/Win32-Development-Binaries/blob/Win32-Development-Binaries/simh-4.0-Beta--2013-03-14-b06505ab.zip

- Mark