Re: papertape repair tape or kit wanted
> From: Mark J. Blair > I'm taking an eBay vacation. Which 12-step program are you in to help with that? :-) I could use a good recommendation!! :-) :-) Noel
RE: papertape repair tape or kit wanted
> > Anyone have a source to purchase the tape to repair a papertape, or a kit > such as what they have here: > > http://physicsmuseum.uq.edu.au/paper-tape-repair-tool I have actually bought such hand punching kits in charity shops (thrift stores) in the UK -- but about 15 years ago. No, the ones I have are not for sale, I still use paper tape a lot... For a splicing jig it's worth remembering that the holes on normal paper tape are on 0.1" matrix so a line of pins soldered to a scrap of stripboard can be used to hold the sprocket holes in alignment. Of course you need the pre-punched sticky tape, but its one part you can easily make. -tony
Re: papertape repair tape or kit wanted
On Nov 29, 2015 1:12 AM, "Bob Rosenbloom" wrote: > > On 11/28/2015 4:47 PM, william degnan wrote: >> >> Anyone have a source to purchase the tape to repair a papertape, or a kit >> such as what they have here: >> >> http://physicsmuseum.uq.edu.au/paper-tape-repair-tool >> >> Thanks >> > You could try westnc.com, Thanks. I sent them an inquiry. If need be I will use a very thin tape and punch the holes manually, but I much prefer the old teletype repair tape or something like it that comes "pre-holed" so you can line up the holes to the existing tape. Bill Degnan twitter: billdeg vintagecomputer.net
Re: papertape repair tape or kit wanted
> On Nov 29, 2015, at 06:29, Noel Chiappa wrote: > >> From: Mark J. Blair > >> I'm taking an eBay vacation. > > Which 12-step program are you in to help with that? :-) I could use a good > recommendation!! :-) :-) It was a cold turkey program. When there was that kerfluffle about PayPal's and eBay's terms of service changing with respect to robo-dialed telemarketing calls, I closed both accounts. They have both since at least partially retracted the bothersome terms, but I've been finding excuses to not rejoin because my acquisitions need some flow rate limiting. :) -- Mark J. Blair, NF6X http://www.nf6x.net/
RE: papertape repair tape or kit wanted
This has worked for me:- https://www.greatrail.com/tours/kerala-southern-india-tour/?tlUrl=%2Fholiday -destinations%2Fasia%2Findia%2F#GCJ6 just added a few days at the start and a few at the start to visit my son in Qatar and some at the end to extend the trip into Mumbai for a few days at the end. Not spent anything on E-Bay for a month... ... a month in China also works well.. Dave G4UGM > -Original Message- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Noel > Chiappa > Sent: 29 November 2015 14:29 > To: cctalk@classiccmp.org > Cc: j...@mercury.lcs.mit.edu > Subject: Re: papertape repair tape or kit wanted > > > From: Mark J. Blair > > > I'm taking an eBay vacation. > > Which 12-step program are you in to help with that? :-) I could use a good > recommendation!! :-) :-) > > Noel
Re: papertape repair tape or kit wanted
I'll open a new PayPal account once I get around to setting up an isolated, dedicated bank account to link it to. It has already been inconvenient not having one when trading with other collectors off eBay. I may open a new eBay account in the future, too. But I don't plan to do either until next year. I'm still catching up on playing with the stuff I've already bought! :) I've made some progress on that matter over the holiday week, and it's been lots of fun. -- Mark J. Blair, NF6X http://www.nf6x.net/
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
On Sat, Nov 28, 2015 at 7:19 PM, Jerome H. Fine wrote: > >Mouse wrote: > > Love that term, "bounce buffer" (I wrote a whole package to support them in a packet switch I did) - I'm officially adopting it, right now! :-) Hey - anything that anyone writes is automatically copyrighted. >>> >>> I realize you...may have been less than entirely serious. But what you >> wrote could easily be taken seriously, especially by someone only >> partially inside our culture. So I'm going to be a minor killjoy here. >> >> Yes, anything written now is automatically copyrighted in most >> jursidctions. But (a) the term "bounce buffer" is small enough and >> obvious enough it probably cannot be copyrighted on its own (and is not >> infringing when copied in isolation), (b) was quite possibly published >> without copyright claim before automatic copyright and is thus in the >> public domain now, and (c) is of uncertain authorship anyway. So... >> >> So first you need permission to use that! >>> >>> ...you actually don't. >> >> Thank you for clarifying that aspect. I just considered > it so ridiculous that anyone would take the joke seriously > that I did not even consider the alternative. > > For the case of the RX02 DYX.SYS device driver, the > use of "bounce buffer" was the most descriptive phrase > that I have ever seen. During a READ request, the following > operations take place: > > (a) Set n = 0 > (a) A request is issued to fill the hardware silo from the floppy media > with sector a+n > (b) The hardware silo is transferred via DMA to the bounce buffer > (c) Set n = n+1 > (d) The next request is made to fill the hardware silo again with sector > a+n > (e) The bounce buffer is copied to the user's buffer one word at a time > Repeat (b), (c), (d) and (e) until finished > > Normally, during the interleave time, the device driver only needs to > transfer > the silo to the user's buffer. When a bounce buffer is required, the > device > driver has the time while the hardware silo is being filled to perform the > copy from the bounce buffer to the user's buffer. So the transfer from the > floppy media is actually bounced off the first data bounce buffer (in a > location > in physical memory which is supported by the hardware) to the final > location > in physical memory (where the user's buffer is located). COOL!! A similar thing was implemented on the old DEC Rainbow 100 (though I'm sure others). To give the software a chance to do some minor things while processing, it physically laid out the 10 sectors as 0 2 3 4 6 8 1 3 5 7 9 so that when reading sequentially, you had half a disk rotation to get your act together to read the next sector. This turned out to be only a small performance win, and was a pita for interoperability, so was done only in the earliest versions. Since these were RX50 disks, I suspected its origins were in the PDP-11s and VAXen that the drives were also attached to. Warner
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
> On Nov 29, 2015, at 1:13 PM, Warner Losh wrote: > > ... > A similar thing was implemented on the old DEC Rainbow 100 (though > I'm sure others). To give the software a chance to do some minor things > while processing, it physically laid out the 10 sectors as 0 2 3 4 6 8 1 3 > 5 7 9 > so that when reading sequentially, you had half a disk rotation to get your > act > together to read the next sector. This turned out to be only a small > performance win, and was a pita for interoperability, so was done only in > the earliest versions. Since these were RX50 disks, I suspected its origins > were in the PDP-11s and VAXen that the drives were also attached to. I didn't know Rainbow did this, but it's familar from the PRO floppy controller. Those use a primitive controller (in fact, *all* PRO controllers are horribly primitive) where the CPU has to pull data from the device, with program I/O. So you'd likely have to use interleaving for decent performance. In any case, it does so. And the track start is offset by 3 sectors per track. And, last but not least, for some strange reason sector 0 is in physical track 1, while physical track 0 contains the highest 10 sectors. Presumably later devices used the same layout for compatibility. The PRO hard drive controller was also programmed I/O, but did't use interleave. And the Ethernet controller had a chip that did DMA (somewhat reliably) but only to on-card memory, so you either had to use that memory for network buffer space, or copy from the card to host memory. paul
Re: A stored collection piece is a Schrodinger's cat
When I joined DEC our field service guys would go out armed with a 745 Tektronix scope (wonderful piece of kit), tools, spare TTL, soldering iron and so on. If you look at the boards from those days you could get the components out and change them. Flip - Chip Modules I love 'em. At that time DEC only hired engineers and then we got trained in sales. So you could normally hold your own with the field service guys. On day I took in a board I had wired up myself and asked if I could use the bench where they did board repairs. Usual comment 'OK which customer are you doing a favour for this time' So I owend up said I wired it. The answer came back oh if its a personal job it gets top prioriy. You can use what ever equipment you want and take whatever components you need. I often borrowed a scope ove the week end. I gathered that a number of DEC products were the result of engineers having an idea and putting it together at home from scrounged parts. Rod On 28/11/2015 23:13, Robert Jarratt wrote: -Original Message- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of rod Sent: 28 November 2015 22:25 To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: A stored collection piece is a Schrodinger's cat Hi I had the exact same fault on my VAX. I took one look at the PSU and ordered up another one pronto. Trouble shoot in that small space no thank you. It works just fine. One day a VAX PSU guru will tell us how to fix it. Rod Smallwood It *is* a fiendishly complex looking thing. The failure mode this time is slightly different to last time though, I intend to see what happens if I give it a completely dummy load, to see if it really is anything to do with the machine or not, there could be a short somewhere that is causing the PSU to shutdown. Regards Rob
RE: A stored collection piece is a Schrodinger's cat
> > So I owend up said I wired it. The answer came back oh if its a > personal job it gets top prioriy. > You can use what ever equipment you want and take whatever components > you need. > I often borrowed a scope ove the week end. I know a chap who runs a small electronics company. He actively encourages his employee(s) to take sensible quatities of small components (resistors, capacitors, 2N3904s, common ICs, etc) for private jobs. His arguement is that if they are doing electronics they must be learning something (or at least keeping their hand in) and might have ideas or solve problems that will help the company. But then he's an engineer not an accountant... -tony
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
On Nov 29, 2015, at 12:13 PM, Warner Losh wrote: > A similar thing was implemented on the old DEC Rainbow 100 (though > I'm sure others). To give the software a chance to do some minor things > while processing, it physically laid out the 10 sectors as 0 2 3 4 6 8 1 3 5 > 7 9 > so that when reading sequentially, you had half a disk rotation to get your > act > together to read the next sector. This turned out to be only a small > performance win, and was a pita for interoperability, ….but, at least you had a functionally redundant sector 3! :-)
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
it physically laid out the 10 sectors as 0 2 3 4 6 8 1 3 5 7 9 so that when reading sequentially, you had half a disk rotation to get your act together to read the next sector. This turned out to be only a small performance win, and was a pita for interoperability, On Sun, 29 Nov 2015, Tapley, Mark wrote: ….but, at least you had a functionally redundant sector 3! :-) That way, a system that could handle 1:1 interleave would get one version of sector 3, while one that could not handle 1:1 interleave would get the other one, and you could have different code for the two kinds of machines.:-) But, that has 11 sectors on the track Were they 512 bytes each? Was it 8"? 5.25"? SD?, DD?, "HD"?
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
On Sun, Nov 29, 2015 at 1:19 PM, Fred Cisin wrote: > it physically laid out the 10 sectors as 0 2 3 4 6 8 1 3 5 7 9 so that >>> when reading sequentially, you had half a disk rotation to get your act >>> together to read the next sector. This turned out to be only a small >>> performance win, and was a pita for interoperability, >>> >> > On Sun, 29 Nov 2015, Tapley, Mark wrote: > >> ….but, at least you had a functionally redundant sector 3! >> :-) >> > > That way, a system that could handle 1:1 interleave would get one version > of sector 3, while one that could not handle 1:1 interleave would get the > other one, and you could have different code for the two kinds of > machines.:-) > > > But, that has 11 sectors on the track > Were they 512 bytes each? > Was it 8"? 5.25"? SD?, DD?, "HD"? > 8" on one side, 5.25" on the other. -- Charles
Re: "Bounce buffer" copyright [was Re: flash (or ide) storage for unibus 11?]
There were a few systems (such as CP/M) that optimized (or attempted to) interleave depending on use. So, "boot" tracks were 1:1, "directory" may have been 2:1 and user data 3:1. Schemes varied widely. One or two even interleaved side-to-side in addition to "skewing track-to-track. Obviously written by a programmer tasked with the job of "Let's see how fast we can get data on or off this thing". --Chuck
Re: Brian Brikon diskette drive tester
On Sat, 21 Nov 2015, Steven Hirsch wrote: I purchased one of these units on eBay and it seems to be working - modulo a few early-80s tantalum caps that went up in smoke. The tester relies on an attached printer to record test results, which are displayed only fleetingly on the front-panel display. Unfortunately it did not come with the printer and I cannot find any information on line. Does anyone have information on this? Is it serial? Parallel? The onnector is a 20-pin, 0.1" DIP header on the rear panel. The tester supplies printer power on a small 3-pin Molex connector. I can probably trace this out on the internal logic board, but thought perhaps another list member owns one of these and can elaborate. I'm also trying to find the manual appropriate to a base Model 723 tester. The one floating around on the net is for an upscale model (723-4M). While there are a number of similarities, I'm running into just enough behavioral difference to make it worth finding the correct docs. There's also a programming and setup "worksheet" document that has not surfaced anywhere. Update: With a bit of patience I have figured out the printer interface. It uses a parallel printer and presents the following pinout on the 20-pin rear-panel header: 1 Gnd 2 n/c 3 +15V Reg 4 Gnd 5 D6 6 D5 7 D4 8 D3 9 D2 10 D1 11 D0 12 Gnd 13 Strobe* (Out) 14 Gnd 15 Gnd 16 Gnd 17 n/c 18 n/c 19 Busy (In) 20 Gnd I have no idea why there's a +15 supply. Note the 7-bit interface. Maybe someone will find this useful. Steve --
Re: papertape repair tape or kit wanted
NOTE: I will pay a generous price for a few inches of papertape repair tape if anyone has any! I am located in Landenberg, PA USAContact me privately if you can help. -- Bill
