On 09/30/2017 10:31 PM, Chuck Guzis via cctalk wrote:
On 09/30/2017 06:29 PM, Jon Elson wrote:
Ahh, but the genius is built into the heads! Note that nobody
recorded 800 BPI on 7-track tapes. I think they supported 200 and 556
BPI, only. There were some low-density 9-track tapes, but generall
On 09/30/2017 06:29 PM, Jon Elson wrote:
> Ahh, but the genius is built into the heads! Note that nobody
> recorded 800 BPI on 7-track tapes. I think they supported 200 and 556
> BPI, only. There were some low-density 9-track tapes, but generally
> most 9-tk tapes were 800 BPI.
Say what? We ce
On 09/30/2017 12:47 PM, Chuck Guzis via cctalk wrote:
What I found a little surprising is that on a 7970 head assembly, the DC
resistance of the 9 track coils is about 76 ohms, but on the 7 track
side, the resistance measures out to about 27 ohms.
Yet, both feed into the same read amplifiers. O
> On Sep 30, 2017, at 11:50 AM, Stefan Skoglund via cctalk
> wrote:
>
> fre 2017-09-29 klockan 12:52 -0400 skrev Paul Koning via cctalk:
>> ...
>> The approach would be somewhat similar to the disk support in SIMH, which
>> does already have "RAW" as one of the formats, meaning direct access
What I found a little surprising is that on a 7970 head assembly, the DC
resistance of the 9 track coils is about 76 ohms, but on the 7 track
side, the resistance measures out to about 27 ohms.
Yet, both feed into the same read amplifiers. On the standard 7970
dual-mode drives, the switching betw
On 09/30/2017 06:58 AM, Tony Duell via cctalk wrote:
One of my tape drives has a set of equal-value resistors connected to
each of the read channels, the others ends of the resistors being brought
out to a testpoint. You connect a 'scope there and read a skewmaster
tape. The idea is that if the
fre 2017-09-29 klockan 12:52 -0400 skrev Paul Koning via cctalk:
> > On Sep 29, 2017, at 12:33 PM, Jon Elson via cctalk
> > wrote:
> >
> > On 09/29/2017 10:56 AM, Henk Gooijen via cctalk wrote:
> >>
> >>
> >>
> >> On a related note my plan is to make a USB-based, Pertec-compatible
> >> contr
Hi Chuck,
How did you program compile if you were missing a semicolon? I'm assuming
you're programming in C and not scripting it somehow... Good news on that
front!
Was it typical to read a record(s) in reverse if an error was encountered?
Sounds like that might require buffering the whole record
On Sat, Sep 30, 2017 at 6:32 AM, Chuck Guzis via cctalk
wrote:
> Still a few too many read errors for my taste, so this weekend is going
> to be a session with a 'scope and alignment tape. I think I've got a
> way to adjust skew--just hook a logic analyzer probe to each channel and
> set the LA
Hi Anders,
I found the reason for my SD card problems--a missing semicolon. There
was supposed to be a stall until SDIO transfer complete; instead of a
stall, the next statement was being executed.
Argh. It's those little things that really trip you up.
At any rate, I've even got read-reverse
On 09/29/2017 03:01 PM, Al Kossow via cctalk wrote:
>
>
> On 9/29/17 11:35 AM, Chuck Guzis via cctalk wrote:
>
>> Does the little Kennedy drive have a vacuum takeup reel?
>
> No, they are tension arm, very similar design to the 7970
>
> I wanted to compare the mechanical design of the 9000 to
On 09/29/2017 01:35 PM, Chuck Guzis via cctalk wrote:
On 09/29/2017 09:00 AM, Al Kossow via cctalk wrote:
On 9/29/17 8:48 AM, Jon Elson via cctalk wrote:
I did a few of these on a lathe years ago. It was a couple minutes job per
reel.
you are also going to have to cut holes near the hub so
On 9/29/17 11:35 AM, Chuck Guzis via cctalk wrote:
> Does the little Kennedy drive have a vacuum takeup reel?
No, they are tension arm, very similar design to the 7970
I wanted to compare the mechanical design of the 9000 to the 7970
but don't know if I have the time/interest any more.
On 09/29/2017 09:00 AM, Al Kossow via cctalk wrote:
>
>
> On 9/29/17 8:48 AM, Jon Elson via cctalk wrote:
>
>> I did a few of these on a lathe years ago. It was a couple minutes job per
>> reel.
>
> you are also going to have to cut holes near the hub so that you can get a
> tape started
> o
> On Sep 29, 2017, at 12:33 PM, Jon Elson via cctalk
> wrote:
>
> On 09/29/2017 10:56 AM, Henk Gooijen via cctalk wrote:
>>
>>
>>
>> On a related note my plan is to make a USB-based, Pertec-compatible
>> controller for it. Not sure how SimH connects with peripherals so I'm
>> /very/ eager to
On 09/29/2017 10:56 AM, Henk Gooijen via cctalk wrote:
On a related note my plan is to make a USB-based, Pertec-compatible
controller for it. Not sure how SimH connects with peripherals so I'm
/very/ eager to talk with someone familiar with its workings. I'll also
release all the board files a
On 9/29/17 8:48 AM, Jon Elson via cctalk wrote:
> I did a few of these on a lathe years ago. It was a couple minutes job per
> reel.
you are also going to have to cut holes near the hub so that you can get a tape
started
on the takeup reel.
Van: Anders Nelson via cctalk<mailto:cctalk@classiccmp.org>
Verzonden: vrijdag 29 september 2017 05:57
Aan: General Discussion: On-Topic and Off-Topic
Posts<mailto:cctalk@classiccmp.org>
Onderwerp: Re: HP 7970E - interest to split?
Update: I bought the Kennedy 9800 as it pushed al
On 09/28/2017 11:44 PM, Anders Nelson via cctalk wrote:
Hi Chuck,
Yeah I could try that but unless I can separate the reel halves from the
hub I'd have to make a jig of sorts to absorb the laser beam on the bottom
side of the cut. Can the sides be separated? And is it possible to cut down
a dust
Van: Steve Malikoff via cctalk<mailto:cctalk@classiccmp.org>
Verzonden: vrijdag 29 september 2017 09:26
Aan: General Discussion: On-Topic and Off-Topic
Posts<mailto:cctalk@classiccmp.org>
Onderwerp: Re: HP 7970E - interest to split?
On my Kennedy 9000s the rubber O-rings have exp
Chuck said:
> On 09/28/2017 08:57 PM, Anders Nelson via cctalk wrote:
>> Update: I bought the Kennedy 9800 as it pushed all my buttons at once.
>>
>> Now I'm looking for 8" mag tapes/reels that will fit! Anyone know where I
>> can find these, maybe 3pcs? I could laser-cut some frosted acrylic or
>>
Hi Chuck,
Yeah I could try that but unless I can separate the reel halves from the
hub I'd have to make a jig of sorts to absorb the laser beam on the bottom
side of the cut. Can the sides be separated? And is it possible to cut down
a dust cover?
=]
--
Anders Nelson
+1 (517) 775-6129
www.erog
On 09/28/2017 08:57 PM, Anders Nelson via cctalk wrote:
> Update: I bought the Kennedy 9800 as it pushed all my buttons at once.
>
> Now I'm looking for 8" mag tapes/reels that will fit! Anyone know where I
> can find these, maybe 3pcs? I could laser-cut some frosted acrylic or
> machine some fros
Update: I bought the Kennedy 9800 as it pushed all my buttons at once.
Now I'm looking for 8" mag tapes/reels that will fit! Anyone know where I
can find these, maybe 3pcs? I could laser-cut some frosted acrylic or
machine some frosted polycarbonate I suppose but I'd rather just buy it,
plus that
Well there goes my evening, thanks Chuck!
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com
On Tue, Sep 26, 2017 at 10:09 PM, Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> On 09/26/2017 06:45 PM, Anders Nelson via cctalk wrote:
> > Cool, is there documentation available for this fo
On 09/26/2017 06:45 PM, Anders Nelson via cctalk wrote:
> Cool, is there documentation available for this formatting and
> error-check/correction algorithm and structure? I'd like to take a look!
A good place to start is the HP "Introduction to Magnetic Tape" in
bitsavers:
http://bitsavers.inform
Cool, is there documentation available for this formatting and
error-check/correction algorithm and structure? I'd like to take a look!
=]
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com
On Tue, Sep 26, 2017 at 12:26 PM, Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:
> On 09/25/201
On 09/25/2017 11:40 PM, Steve Malikoff via cctalk wrote:
> Yes, you will need the controller to at least format, but not sure about just
> reading/writing.
Looking at the interface, it's pretty much a "raw" interface.
As in a lot of things in life, timing is everything in tapes.Tape
blocks
> Well, as others have pointed out, a "tape transport" is not the whole
> ball-of-wax. You need the ability to format the tape into blocks and then
> control tape motion in terms of those blocks. That's what you'd be
> responsible for in your added electronics. From the Introduction in the
>
and formatter
in order to generate properly formatted IBM compatible
tapes."
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Anders Nelson
via cctalk
Sent: Tuesday, September 26, 2017 1:41 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subjec
om: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Anders Nelson
via cctalk
Sent: Tuesday, September 26, 2017 1:41 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: HP 7970E - interest to split?
Ah, yeah that's actually better for my purpose. I'm more concerned with
gt; From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Anders
> Nelson via cctalk
> Sent: Monday, September 25, 2017 7:01 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: HP 7970E - interest to split?
>
> Hmmm, interesting. How does the 7970 compar
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Anders Nelson
via cctalk
Sent: Monday, September 25, 2017 7:01 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: HP 7970E - interest to split?
Hmmm, interesting. How does the 7970
Hmmm, interesting. How does the 7970 compare to the Kennedy 9800?:
http://www.ebay.com/itm/Kennedy-9800-9-Track-Data-Tape-Subsystem/232493086636
For the same price the Kennedy drive looks more beautimous...
=]
--
Anders Nelson
+1 (517) 775-6129
www.erogear.com
On Mon, Sep 25, 2017 at 2:18 PM
ED#WROTE
What is really scarce is a 7 track 7970b!
I have a 7970B (needs some repair) that I would LOVE to trade for a 7970E.
J
What is really scarce is a 7 track 7970b!
Had one once... it was the first used HP item I ever sold when I was in
the used computer biz early 80s.
Wish now I had kept it!
Ed#
In a message dated 9/25/2017 10:26:10 A.M. US Mountain Standard Time,
cctalk@classiccmp.org writes:
On
On 09/25/2017 08:27 AM, Anders Nelson via cctalk wrote:
> Cool! Aaa, good to know one of them can't be used individually.
>
> What might be involved in using one with a PDP-8/e emulated on SimH? I can
> build/program any sort of custom USB device to interface this big stuff,
> which I'll open-sour
That sounds very plausible, Mike.
It's too far for me, but I bet somebody local could get both lots for
$1000, by picking them up and saving them the hassle of crating etc.
--
Robert
On Mon, Sep 25, 2017 at 12:07 PM, Mike Loewen via cctalk
wrote:
> On Mon, 25 Sep 2017, Anders Nelson via cctalk
On Mon, 25 Sep 2017, Anders Nelson via cctalk wrote:
Hi there, here's an eBay auction for two HP 7970E tape drives that appear
to function:
http://www.ebay.com/itm/VINTAGE-HP-7970e-DUAL-Tape-Drive-Cabinet-Reel-to-Reel-Player-/192204691239
I'm curious if anyone is looking for one of these drive
Cool! Aaa, good to know one of them can't be used individually.
What might be involved in using one with a PDP-8/e emulated on SimH? I can
build/program any sort of custom USB device to interface this big stuff,
which I'll open-source of course. But does it need special power/startup
stuff beyond
I may be convinced to split it with you. I could always use another 7970E. I
can't tell from the pictures if one is master and one is slave only
though.. that would be key.
Hi there, here's an eBay auction for two HP 7970E tape drives that appear
to function:
http://www.ebay.com/itm/VINTAGE-HP-7970e-DUAL-Tape-Drive-Cabinet-Reel-to-Reel-Player-/192204691239
I'm curious if anyone is looking for one of these drives. I'm not sure if I
want to pull the trigger on somethi
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