[Simh] Announcement: back10

[Rich Alderson]

> From: "Tim Stark" <fsword7 at verizon.net>
> Date: Mon, 20 Feb 2017 17:24:40 -0500

> Thanks for publishing this.  I was able compile it into executable file on
> MinGW64/MSYS environments for Windows without any problems.  With MinGW64
> compiler, it just complaint missing utsname.h include file.  With MSYS
> compiler, it worked fine.

> I was able extract dskaa.sav file from KLAD tape image. I examined contents
> but I have a question for it.

> Can back10 handle binary files for extracts and backups?  What kind of format
> does extracted binary file use?  I need good SAV files to debug my MSE
> emulator (KS10 emulation).

Only by accident.  Tops-10 and TOPS-20 binary files are stored in coredump
format on tape and emulated tape.

> Does anyone know FTP high density format that I am looking for?  I only know
> core-dump and ANSI formats for PDP10 tape formats according to back10 source
> codes.

High-density format, available for TU72 tape drives connected to PDP-8/A based
controllers, is also the default for FTP transfers.  Every pair of 36 bit words
in the file is stored in 9 8-bit frames on the tape (or 9 8-bit bytes on an
extended-8008-compatible computer) as follows

Word 1:   0  1  2  3  4  5  6  7
     	  8  9 10 11 12 13 14 15
	 16 17 18 19 20 21 22 23
	 24 25 26 27 28 29 30 31
W1/W2:	 32 33 34 35  0  1  2  3
Word 2:	  4  5  6  7  8  9 10 11
	 12 13 14 15 16 17 18 19
	 20 21 22 23 24 25 26 27
	 28 29 30 31 32 33 34 35

The KS diagnostics, like those for the KL, expect that there is a running front
end processor which can stuff the bits into the appropriate place in memory and
start them.  If you want to run them without a front end, you'll have to read
the diagnostics sources to see what needs to be set up where in memory; besides
the actual diagnostic, DDT and a common subroutine RTL get loaded into specific
places.

                                                                Rich