On Feb 9, 2017, at 9:14 PM, Zane Healy <healyzh at
On Feb 9, 2017, at 5:39 PM, Paul Koning
<paulkoning at comcast.net> wrote:
I'm looking at a set of RSTS V7 magtape images (a release kit) which have an odd
format that gives SIMH fits.
In the container formats I'm used to, each tape block image is preceded and followed
by the data length as a 4-byte value. In SIMH that's rounded up to even, in E11
format it's not, but apart from that this is how things work.
The V7 tape images don't match that format. It looks like each block contains not
just the data but also 2 more bytes, and the data length value represents that extra 2
bytes. So the tape label is 16 bytes, not 14, and the data blocks are 514 bytes, not
Does this ring any bells? Where do those extra bytes come from? Can SIMH be told to
deal with this or does it require a repair program to fix the format?
What is the file extension? TPC or TAP? I forget which SIMH uses, but there used to be
a converter available to go from the format that many of the tape images are in, to the
one SIMH uses.
On bitsavers they are .TAP files. What is TPC format?