From: berdpee@ami.com.au Newsgroups: alt.sys.pdp10 Subject: DECTAPE - recovery of data Date: Sat, 07 Sep 2002 02:12:05 GMT Message-ID: <3d795db6.189453@news.ami.com.au> X-Newsreader: Forte Free Agent 1.21/32.243 NNTP-Posting-Host: 203.55.31.65 X-Trace: 7 Sep 2002 10:11:42 +0800, 203.55.31.65 Lines: 19 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!feedme.news.mediaways.net!news.belwue.de!newsfeed01.sul.t-online.de!newsfeed00.sul.t-online.de!t-online.de!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news1.optus.net.au!optus!news.uwa.edu.au!nntp.waia.asn.au!usenet.per.paradox.net.au!203.55.31.65 Xref: chonsp.franklin.ch alt.sys.pdp10:11842 Hello Folks, I have designed a hardware interface to connect to the TU56/TC11 - G888 read amplifier outputs. This will give one NIBBLE per frame, the block/mark track and the three data tracks. These will be transferred to a PC's hard drive. I am told that other/s have written programs which will convert this to source code so I see no point in trying to invent the wheel again. But at this point I can easily align the bits in the nibble to suit the software, so please can the programmer tell me in what order are the bits in the nibble preferred. Thanks, Rolie Baldock. aeolus ###### Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.sys.pdp10 Subject: Re: DECTAPE - recovery of data References: <3d795db6.189453@news.ami.com.au> Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 06 Sep 2002 22:10:53 -0700 Message-ID: Lines: 19 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: 209.66.107.17 X-Trace: 6 Sep 2002 22:35:57 -0700, 209.66.107.17 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!feedme.news.mediaways.net!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!logbridge.uoregon.edu!arclight.uoregon.edu!enews.sgi.com!news.spies.com!209.66.107.17 Xref: chonsp.franklin.ch alt.sys.pdp10:11854 berdpee@ami.com.au writes: > I have designed a hardware interface to connect to the TU56/TC11 - > G888 read amplifier outputs. This will give one NIBBLE per frame, the > block/mark track and the three data tracks. These will be transferred > to a PC's hard drive. I am told that other/s have written programs > which will convert this to source code so I see no point in trying to > invent the wheel again. But at this point I can easily align the bits > in the nibble to suit the software, so please can the programmer tell > me in what order are the bits in the nibble preferred. My program is dectape_decode.c, which may be found at: http://www.brouhaha.com/~eric/retrocomputing/dec/dectape/ Two input file formats are supported. They are documented at the top of the source code. Since writing that code, I have learned that Doug Jones has a different raw DECtape file format, so the next time I have occasion to revise the program, I'll add support for his format. ###### From: berdpee@ami.com.au Newsgroups: alt.sys.pdp10 Subject: Re: DECTAPE - recovery of data Date: Sun, 08 Sep 2002 03:34:08 GMT Message-ID: <3d7ac054.1091248@news.ami.com.au> References: <3d795db6.189453@news.ami.com.au> X-Newsreader: Forte Free Agent 1.21/32.243 NNTP-Posting-Host: 203.55.31.74 X-Trace: 8 Sep 2002 11:33:44 +0800, 203.55.31.74 Lines: 36 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news1.optus.net.au!optus!news.uwa.edu.au!nntp.waia.asn.au!usenet.per.paradox.net.au!203.55.31.74 Xref: chonsp.franklin.ch alt.sys.pdp10:11843 Hello Eric, My hardware puts the nibble in the low order bits of the byte. The high order bits are not written to. BUT PLEASE is the block/mark track on BIT 0 or BIT 3 and is DATA TRACK 1 on bit 1 or bit 2 etc.. etc. I can easily change the connections whilst it is in the drawing stage whereas it will be more difficult later. Regards. On 06 Sep 2002 22:10:53 -0700, Eric Smith wrote: >berdpee@ami.com.au writes: >> I have designed a hardware interface to connect to the TU56/TC11 - >> G888 read amplifier outputs. This will give one NIBBLE per frame, the >> block/mark track and the three data tracks. These will be transferred >> to a PC's hard drive. I am told that other/s have written programs >> which will convert this to source code so I see no point in trying to >> invent the wheel again. But at this point I can easily align the bits >> in the nibble to suit the software, so please can the programmer tell >> me in what order are the bits in the nibble preferred. > >My program is dectape_decode.c, which may be found at: > http://www.brouhaha.com/~eric/retrocomputing/dec/dectape/ > >Two input file formats are supported. They are documented at the >top of the source code. > >Since writing that code, I have learned that Doug Jones has a different >raw DECtape file format, so the next time I have occasion to revise the >program, I'll add support for his format. aeolus ###### Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.sys.pdp10 Subject: Re: DECTAPE - recovery of data References: <3d795db6.189453@news.ami.com.au> <3d7ac054.1091248@news.ami.com.au> Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 07 Sep 2002 21:32:58 -0700 Message-ID: Lines: 21 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii NNTP-Posting-Host: 209.66.107.17 X-Trace: 7 Sep 2002 21:58:12 -0700, 209.66.107.17 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!HSNX.atgi.net!news.kjsl.com!news.spies.com!209.66.107.17 Xref: chonsp.franklin.ch alt.sys.pdp10:11853 I wrote: > My program is dectape_decode.c, which may be found at: > http://www.brouhaha.com/~eric/retrocomputing/dec/dectape/ > > Two input file formats are supported. They are documented at the > top of the source code. berdpee@ami.com.au writes: > My hardware puts the nibble in the low order bits of the byte. The > high order bits are not written to. BUT PLEASE is the block/mark > track on BIT 0 or BIT 3 and is DATA TRACK 1 on bit 1 or bit 2 etc.. > etc. > > I can easily change the connections whilst it is in the drawing stage > whereas it will be more difficult later. The input formats are documented at the top of the source file. Sounds like you want to use David Gesswein's format. However, it's really easy to change the software to support a different format if necessary.