test-drb March 2007

test-drb@ccmp.vtda.org

239 participants
488 discussions

by dm561＠torfree.net

----------------Original Message: Date: Mon, 12 Mar 2007 13:24:49 -0700 (PDT) From: Fred Cisin <cisin at xenosoft.com> Subject: Re: baud modifier In addition to the speed, are the protocols the same? For example, if you were to just slow down a Bell 212 (1200 bps) modem to 300 bts per second while still using the same frequencies and encoding, that would NOT enable a Bell 103 to be able to communicate. It would ALSO be necessary to switch the encoding to a FSK using the Bell 103 frequencies. I could certainly feed 10 characters per second through a V.90. But that would NOT provide the CCITT V.18? protocol needed for most 110 baud devices. --------------Reply: And then there may be the little matter of RS-232 <> current loop conversion... m

19 years

ftp archives disappearing?

by ken＠seefried.com

From: Jules Richardson <julesrichardsonuk at yahoo.co.uk> >It's a shame that there wasn't a widely-adopted data transfer protocol that >was truly bi-directional. True, though there are and have been many good not-so-widely adopted solutions. >Both FTP and HTTP largely revolve around moving data >in one direction only. Even given the predominant client/server model of the >time, it's a shame that the "main" protocols weren't designed with the >foresight that one day we might want to move just as much stuff *to* >a site as we were taking *from* it. Client/server is still essentially the model for the vast majority of internet use: it's almost all asymmetric. As in, depending on the site, 100 to 1000 times or more as much data going one way than the other. Even profiling sites like YouTube, where people actually do upload large amounts of data, individual clients download far more. HTTP was designed for the common case in it's problem space. It shouldn't be surprising that it's not optimal for other cases.

19 years

Report on vintage "Programmer Electronnic Control" alias "RAF Tornado Computer" (fwd)

by erik＠baigar.de

Hi Roger, I am sorry, I just discovered a new "feature" of the PEC - so please ignore the "divide data" of the last email. Perhaps you can explain this. My test porgram for the DIV was implented as loop using the index register (B) to save the results to the core as follows: load values DIV/MUL load index register from pointer store accu to core with index move Q to accu load index register from pointer store accu to core with index increment pointer do next values And I noticed, that loading the index register (B) influences the Q register! In the abouve example my multiply failes, too. If I do it in the following way: load values DIV/MUL store accu to core-tmp move Q to accu load index register from pointer store accu to core with index load accu from core-tmp load index register from pointer store accu to core with index increment pointer do next values Than the MUL works as desired (with 0x23 as memory operand): Akku before: 001 005 010 020 050 100 120 150 200 500 fff Q before: fff 500 200 150 120 100 050 020 010 005 002 Akku after: 000 000 000 000 001 004 004 005 008 015 fff Q after: 023 0af 230 460 2f0 300 760 5f0 600 700 7dd Especially, you can see, that 0x50*0x23 leads to 0x12f0 which is caused be the fact, that bit 11 is not used in the shift operations and thus bit11 of Q is not valid and the MUL is in fact 11bit*11bit unsigned. So now let's repeat the experiment with the "DIV" instruction using the proper code (again memory operand is 0x23): Akku after: 03b 125 3a9 751 ff5 f43 f23 ef1 e3f b31 fc5 Q after: 01d 092 1d4 3a8 7fa 7a1 791 778 71f 598 7e2 Still I cannot see the divide instruction behind these numbers. Now I an sure, that the framework is OK since I checked it with the logic analyzer. Below I show you the list file of my assembler, do you think, this helps in out communication or would you prefer to get listings in your 8/23 you kindly explained in your last email. It would not be a problem to teach my assembler to generate such output, too. Best regards and good evening, Erik. LISTING OF DIV-Test: 13 @ 0019 ORG 0 ; 14 @ 0020 ; 15 @ 0021 0000 023 data: DW 0x23 ; 16 @ 0022 0001 000 Index: DW 0 ; 17 @ 0023 0002 FF3 Counter: DW 0xfff-12 ; 18 @ 0024 0003 000 a1: DW 0 ; 19 @ 0025 0004 000 b1: DW 0 ; 20 @ 0026 ; 21 @ 0027 ORG 0x20 ; 22 @ 0028 ; 23 @ 0029 0020 001 accu: DW 0x1 ; 24 @ 0030 0021 005 DW 0x5 ; 25 @ 0031 0022 010 DW 0x10 ; 26 @ 0032 0023 020 DW 0x20 ; 27 @ 0033 0024 050 DW 0x50 ; 28 @ 0034 0025 100 DW 0x100 ; 29 @ 0035 0026 120 DW 0x120 ; 30 @ 0036 0027 150 DW 0x150 ; 31 @ 0037 0028 200 DW 0x200 ; 32 @ 0038 0029 500 DW 0x500 ; 33 @ 0039 002A FFF DW 0xfff ; 34 @ 0040 ; 35 @ 0041 ORG 0x30 ; 36 @ 0042 ; 37 @ 0043 0030 FFF ssr: DW 0xfff ; 38 @ 0044 0031 500 DW 0x500 ; 39 @ 0045 0032 200 DW 0x200 ; 40 @ 0046 0033 150 DW 0x150 ; 41 @ 0047 0034 120 DW 0x120 ; 42 @ 0048 0035 100 DW 0x100 ; 43 @ 0049 0036 050 DW 0x50 ; 44 @ 0050 0037 020 DW 0x20 ; 45 @ 0051 0038 010 DW 0x10 ; 46 @ 0052 0039 005 DW 0x5 ; 47 @ 0053 003A 002 DW 0x2 ; 48 @ 0054 ; 49 @ 0055 ORG 0x50 ; 50 @ 0056 ; 51 @ 0057 0050 000 resultACCU: DW 0 ; 52 @ 0058 ; 53 @ 0059 ORG 0x60 ; 54 @ 0060 ; 55 @ 0061 0060 000 resultSR: DW 0 ; 56 @ 0062 ; 57 @ 0063 ORG 160 ; Programmstart 58 @ 0064 ; 59 @ 0065 ; ----------------------------------------------------------------- 60 @ 0066 ; 61 @ 0067 00A0 001 reset: LDI Index ; 62 @ 0068 00A1 430 LDA ssr ; 63 @ 0069 00A2 EA0 MATSR ; 64 @ 0070 00A3 001 LDI Index ; 65 @ 0071 00A4 420 LDA accu ; 66 @ 0072 00A5 D00 DW 0b0110100000000 ; DIV? 67 @ 0073 00A6 503 STA a1 ; 68 @ 0074 00A7 E20 MSRTA ; 69 @ 0075 00A8 504 STA b1 ; 70 @ 0076 00A9 001 LDI Index ; 71 @ 0077 00AA 560 STA resultSR ; 72 @ 0078 00AB 403 LDA a1 ; 73 @ 0079 00AC 001 LDI Index ; 74 @ 0080 00AD 550 STA resultACCU ; 75 @ 0081 00AE A01 INC Index ; 76 @ 0082 00AF A02 INC Counter ; 77 @ 0083 00B0 990 RJAN reset ; 78 @ 0084 00B1 800 stop: RJMP stop ; 79 @ 0085 ; 80 @ 0086 ORG 4095 ; Freeze to prevent jump-over 81 @ 0087 0FFF 800 looi2: RJMP looi2 ; in free running mode

19 years

8" drive variations

by Watzman＠neo.rr.com

8" drives do exist in both hard and soft sector formats, but soft-sector is overwhelmingly dominant (probably more than 97%). There is only one rotational speed (360RPM), and they all have 77 tracks. Some have one side, some have two sides. But after that, all hell breaks loose, because the density as well as both the number of sectors per track and the sector size can take on almost any values (and some formats have track 0 in single density with all other tracks in double density). Sector size can be any of 128, 256, 512 or 1024 bytes per sector, and the number of sectors is also not well standardized. Some early drives will not interface to a 765 well; later drives should not be a problem. However, the western digital chips had more flexibility and can do formats that the 765 cannot do.

19 years

PDP-11/40 videos

by wacarder＠earthlink.net

> Tom Peters said: >I'd like to see the blinkenlights on the front panel. > >-T Videos in Apple Quicktime format are at: http://www.woffordwitch.com/videos.asp *** WARNING - I have not downsized these videos *** THEY ARE HUGE - you'll be waiting a while if *** you are on dial-up. I'll downsize them later and/or *** put them in another format (wmv?). Ashley

19 years

Using DECmateI RX02 drives in the pedestal

by fsmith＠ladylinux.com

On Tuesday 13 March 2007 12:47:04 pm cctalk-request at classiccmp.org wrote: Ethan Wrote .. > You don't have to pull the drives - the DB25 connector on the back of > your pedestal is a DEC-standard way of externally cabling RX02s - it > was done the same way with the table-top RX02 shell for the MINC-11. > If you get your 11/73 together, you could aquire or make a cable to go > from the RXV21 to a DB25, then use a DB25-to-DB25 cable from the 11/73 > to the back of your DECmate pedestal. ?No removal required. Really I was wondering about that connector. Sorry for the ignorance. I guess I better read up on this. This could be quite workable. Thank you very much for this tip. > Personally, I maintain an older box with a 5.25" floppy that reads and > writes RX50s just fine. ?Haven't had occasion to fire it up lately, so > I should probably do that to see if the heads have glued down to the > platters or if the CMOS battery as died. ?It's an old 486DX2/66 VLB > box - too old to run a modern OS, but powerful enough to run an OS > capable of capturing diskette images and squirting them over an > Ethernet card to something "modern" for burning and archiving. I will have to read up on the archives. I was not so sure if the drives were interchangable. I have a couple old servicable PC's around here. Certainly I can explore this intriging option. Good tips ... Very Helpful Thank You :-) -- Kindest Regards, Francesca Smith "No Problems Only Solutions" Lady Linux Internet Services Baltimore, Maryland 21217

19 years

Introduction And Questions About Media Preservation "Mostly DecStuff

by fsmith＠ladylinux.com

On Tuesday 13 March 2007 12:26:16 am cctalk-request at classiccmp.org wrote: Jay Wrote .. > If you have RK05/6 & RLxx & RXxx drives that you completely trust as being > good working drives, load up vtserver and make images of the packs over a > serial port to your PC. Then you can put the images up online (or I can put > the images up on classiccmp.org under /PDP-11). Yep I am not real trusting of the drives I have. I have two RL02's one RL01 and two RK05's coming. The RK05's are known working good. But .. until I actually get a "scratch pack" I am not mounting anything in any of these drives. The RL's I need to test with media I don't care about and also I need to find a qbus or unibus controller in any case. I have about 75 or so RL02's/RL01's and about 20 RK05's. Two of the RK05's are extremely precious to me. I used these in the early 80's with a 11/45 and 11/70 I had in a lab in California. The thing is that they stayed behind at the place I use to work at while I moved on to work on other exciting things like VAX's. Then about a year or so ago. I saw these RK05's on E-Pay. I WAS absolutely Floored when I opened up the box and they were my packs looking just like when I left them. What is the chance of that happening. ??? (Now I have to find the 11/70 and 11/45 :-) ) So I want the data off these and I want them back since well ... They are in a way a part of my first love :-) Ok well as far as computers go that is :-) > I'd be happy to do the RL01, RL02, RX01, and RX02 media for you. My RK05 > isn't working yet, don't have an RK06, and haven't tested my TU81+ yet. Ok cool. Most the RL02's and RL01's are actual factory dec labeled software packs. Let me get a list together. It will take a while to transcribe all of them. I have about 15 RK05's coming in a week that contain DEC software also. Soon after this I will have the drives and should be able to work the stuff off them after finding a couple blank scratch packs. Floppys I have GADS of as in huge huge amounts of software and archives. Most of its from some long forgotten Xray spectroscopy program. (From a rescue not anything I was working on nor have a clue about) But there is quite a few with working RT11 and RSX11 and layered products on them. This may be easier once I get that 11/73 going. I am close to having some working Shugart 8 inch floppys. And I got about 5 or so RX50 drives floating around here. -- Kindest Regards, Francesca Smith "No Problems Only Solutions" Lady Linux Internet Services Baltimore, Maryland 21217

19 years

PDP-11/40 videos

by wacarder＠earthlink.net

>> Videos in Apple Quicktime format are at: >> >> http://www.woffordwitch.com/videos.asp >> >> *** WARNING - I have not downsized these videos >> *** THEY ARE HUGE - you'll be waiting a while if >> *** you are on dial-up. I'll downsize them later and/or >> *** put them in another format (wmv?). > > >FWIW, DivX/MPEG4 or MPEG2 are much better (portable!) formats than the >garbage that is WMV. > >Pat I'll do something better later today. I just dumped those out there as they were in my camera's native format. I should be able to get something good in just a meg or two. Ashley

19 years

Interesting Book

by marvin＠rain.org

I picked up "Future Mind" by Edward Lias, (c)1982 at UCSB, and the first skimming shows it to be a pretty interesting book. Things I found interesting were in the chapter titled "How Many Would You Like?", that included marketing research type information. A couple of examples are Small Business Computer Census and Minicomputer Census for 1980 that give the number of installations for a number of computer vendors. Included are some that are not well known, Modular Micro, Artronix, Bytronix, New England Digital Corp., etc. One of the charts was a table showing the speed in operations per second for about 100 computers. This is a pretty expensive book, but well worth the $1.00 or so that a number of online bookstores are selling it for.

19 years

Components & Tools (Was: Re: baud modifier)

by RodSmallwood＠mail.ediconsulting.co.uk

Try Maplin http://www.maplin.co.uk/ (Components Tab) They still stock 74 and 4000 series devices. Rod Smallwood -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: 12 March 2007 23:06 To: cctalk at classiccmp.org Subject: Re: Components & Tools (Was: Re: baud modifier) > H. Gee's in Cambridge is a real blessing in comparison - wide range of > > components and still staffed by people who know what they're talking > > about Having spent a few years studying and then working in Cambridge, I can confirm hhat H Gee was a place I spent far too much money :-) There's nothing much in London either. There's Cricklewood Electronics who have an amazing range of old ICs in stock (heck, they had a TTL chip I could find listed _nowehre_ else, not even on the web). > You lucky fellow, nothing like that in northwest UK that I know of > About the best I seem to be able to do is CPC (ex Farnell), but as Tony > commented the other day, the website is a disaster area for finding I'm lucky. I have a friend who runs a small electornics company and he gives me old RS and Farnell catalogues from time to time. I can find what I need there, type the order codes in on the website to se eif they're still available (of if the RoSH directive has caused them to be replaced), and if not to see what alternatives there are. > That's a cracking idea. Anyone know of good suppliers in the UK? RS seem to > be useless these days too. RS and Farnell are both fine once you've found what you want. The have a reasonable range, and are reliable. Mind you, there are some odd things that I can't find a single UK supplier for (top of the list at the moment is a 36 pin microribbon socket, cable mounting -- think of a socket that mates iwth a Centronics plug and which goes on a cable, not a chassis). -tony

19 years

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test-drb March 2007