On Sun, 3 May 2015, Timothe Litt wrote:
When asking a question like this, it sure would help if you included the basic information required to answer it.
Yeah, that would help. Sorry, was running around doing a bunch of things when I sent that off.
What is the source system? What hardware and software wrote it? What commands read the tape "on the source system"?
An SC-40 with a DLT-7000 tape drive hanging off it, using a (Probably heavily modified) TOPS-10.
.ASSIGN MZA50: TAPE: .RUN BACKUP /TAPE TAPE: /SSNAME KDK /SAVE KDK:
You can try DIRECT under TOPS-10, as it knows how to recognize a number of tape formats. .direct /s/marks mta0:
Thanks, will try that.
That said: t10backup has a number of issues (as it turns out, I'm in the middle of writing a replacement).
Ahhh.
Here's a guess: A standard tops-10 backup tape does indeed have a blocksize of 2720 on 9-track tape in core dump format = (32 word header + 512 word page) * 5 frames/word.
Yeah, which this seems to not be. ;)
2448 sounds like it was written in the rarely-used high-density mode, which is 4.5 frames/word. This was supported by the DX20, but is not emulated by simh. The DX20 was not supported on the KS.
Hmmmm. I wonder why the SC-40 running this TOPS-10 build is using high-density mode then?
I've heard that there's some sort of command to change the tape format, any ideas?
(I can rewrite the tape, I wrote the tape giving me issues yesterday afternoon)
TOPS-10 didn't support this mode, but you might have a TOPS-20 interchange tape (backup-compatible) that was written on it. Trivia: this is a rare case where TOPS-20 supports a hardware feature that TOPS-10 does not.
If I have time later today, I'll write a conversion utility to convert a tape image from high-density to core dump mode. I suspect this will solve your problem - but in any case, it should be generally useful.
Thanks, yes - that should help.
Can you provide a (preferably small) sample tape so that I can verify this analysis?
Sadly, it's >300M (explains the high-density mode, now that I think about it) and I must control its spread so I'll send it to you off-list.
-- Cory Smelosky http://gewt.net Personal stuff http://gimme-sympathy.org Projects _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
