23 Jun
2020
23 Jun
'20
10:50 p.m.
On 6/23/20 8:18 PM, John Forecast wrote:
Looks like a standard DOS/BATCH-11 tape file header.
The first 6 bytes and the last 2 bytes are the file name in rad50 - ?HMMMD0P.SAV?.
Depending on where/when it was written the header can be either 12 or 14 bytes:
Format of DOS-11 magnetic tape header records:
.rad50 /fn1fn2/ ;1st 6 letters of filename
.rad50 /ext/ ;3-letter extension
.byte proj,prog ;ppn (display it in octal)
.word prot ;protection code, usually <233> octal
.word date ;date: (year-1970.)*1000.+(day within year)
.rad50 /fn3/ ;[optional] letters 7::9 of filename
Length=14. bytes (or 12. if no fn3, like in actual DOS/BATCH)
Thanks for straightening that out--all I know is that the tapes are from
an 11/70, which isn't much information, admittedly.
--Chuck