Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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.

Re: HP 7970E - interest to split?

> 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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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,

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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.

Re: HP 7970E - interest to split?

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 >

Re: HP 7970E - interest to split?

> 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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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.

RE: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

RE: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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:

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

RE: HP 7970E - interest to split?

> 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

Re: HP 7970E - interest to split?

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 Subject: Re: HP 7970E

RE: HP 7970E - interest to split?

[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 the data interfa

Re: HP 7970E - interest to split?

l 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 t

RE: HP 7970E - interest to split?

-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

Re: HP 7970E - interest to split?

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

RE: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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,

Re: HP 7970E - interest to split?

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

Re: HP 7970E - interest to split?

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

RE: HP 7970E - interest to split?

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.