test-drb April 2013

test-drb@ccmp.vtda.org

205 participants
273 discussions

RL drive select plugs. What is magic about 3?

by ian_primus＠yahoo.com

I've been doing a bit with an 11/23+ setup and a few RL drives, and I've run into something odd. I currently have select plugs 0, 1 and 3. If I plug in two drives, 0 and 1, I can boot from either one, and once in RT11, I can access the other one. Easy. If I connect two drives, 0 and 3, however - I can only use drive 0. All accesses to drive 3 result in an error. Can't boot from it, can't access it from RT11. Thinking that maybe the plugs had to be in order, I connected only one drive, drive 1, and was able to boot it and use it just fine. Then, swapping the 3 plug into that single drive, can't boot from it. And I've shuffled this plug around into a couple of drives, and none of them work with it. There's no damage to the plug itself, and all the drives work otherwise. Unfortunately, I don't have enough cables to connect more than two drives at once. I also don't have a drive 2 plug to try. And yes, I have a terminator. Any ideas? -Ian

11 years, 6 months

Xerox 820-II FDC (was Re: Chip 733w01522 on xerox 820-II FDC

by ard＠p850ug1.demon.co.uk

> U1 (74S288) and U2 (74S174) together constitute a "finite state machine" (so > they told to me cause I'm not so expert) whose purpose is to provide a read A finite state machine (sometiems shortend to a 'state machine') is a way of designing and building sequential logic circuits -- that is circuits where the outputs(s) depend not only on the inputs now, but also on previous sets of inputs. The basic idea is tha tthe circuit stores internally a 'state', normally as an n-bit binary number in n D-tyoe flip-flopes (that's the 74LS174 in your circuit, a hex D-type flip-flop). All flip-flops are clocked at the same time to change to a new state, Andthen there is a block of combinatorial logic (a cricuit where the outputs depend only o nthe inouts now, not what they were) which has as inputs the external inptus ot the state machine and the outputs of the D type flip-flops and which produces the inputs to the D-type flip-flops to give the new state. Sievn a ROM is a gnneral combinatorial circuit, you can make a stte machine from a ROM and a set of D-type flip-flops, aas here. > Who wrote that article decided to build itself a FDC controller card for his > xerox 820-II extracting a block of its schematic from a Kaypro-II's > schematic really making very few changes and using a FDC WD1793 + WD9216 for > external separator data. > Due to its small number of components, and having already a WD1797 I'd just > need of a WD9216 (i hope to find it on the Internet yet) and wiring it would > be maybe more simple. The 9216 was a very common data separator about 25 eyars ago. It was used on a lot of PC/XT cloen FDC cards (not on the original IBM one though) and in other machines too. I am pretty sure it was made by several manufacturers. > Last suggestion (always from the so expert Chuck that I thanks so much) > would be to use a WD2797 instead of WD1797, but I'm not a designer and while > i can understand something of all those things it's very hard for me to > change schematics or adjust components. The 2979 is essential a 1797 with an intenral data separator. It works well, but IIRC there are 3 analogue adjustments associated with it (a couple of puse widths and the free-running frequency of a VCO). It's not hard to set these up, but you do need a 'socpe or logic anlyser to do it. The 9216 data separator IIRC needs no external adjustments. -tony

11 years, 6 months

pdp-11/23 config (was: Re: Qbus identification)

by Arno_1983＠gmx.de

allison <ajp166 at verizon.net> wrote: > Look uo the backplan to find out its configuration. >From my initial posting: > > It is the BA11 variety and contains a H9273 backplane, which as far as I could find out is QQ-CD Am I missing something here? > Also read the fine manual for the quad width 11/23 you will find there > are jumpers/switches for use in AB/CD backplanes. Most quad width cards also conform to that. Also from my initial posting: > > The M8189 is a quad-width board, but with the CD part configured > > for a serpentine backplane (the manual mentions two jumpers to be removed when using in another > > environment to avoid shorting signals together) Am I missing something here? > CD lines are needed for RL11 controller (two board RL01/02 controller). Ah, thanks. Alas I've already been promised the single board variety of that option. > And if all else fails you can replace the backplane with one that is > AB/AB as I've done that many times. Thereby sacrificing the option of integrating any CD-dependent boards I might happen across in the future. Best idea I could think of until now would be a mixed (Q/CD - Q/Q) layout backplane, but I do not know whether these even exist in the required 9-slot form factor. Anyway, I think I'll treat the backplane as a given constant right now (except from probably expanding it to Q-22, see below) and look for the "right" boards to populate it. David Riley <fraveydank at gmail.com> wrote: > The H9273 is perfectly compatible with an 11/23 CPU; there > is a jumper you can set for 18-bit use. Obviously, though, > turning it into a 22-bit backplane is preferable. > Fortunately, that's pretty easy. Meh...I've been hearing that I might run into problems with some other processors (LSI-11(/2), very early KDF11-A versions), should I ever need to use the backplane as a test platform for one of those in the future. Is that problem the one simply worked around with some insulating tape over the BDAL18:21 connector pads? > > The M8189 is a quad-width board, but with the CD part configured > > for a serpentine backplane (the manual mentions two jumpers to be removed when using in another > > environment to avoid shorting signals together), so again no "meaningful" use of the CD lanes. > Correct. The Qbus PDP-11s only used the CD lane for PMI > (or custom logic, if you had that). Sounds interesting, could you elaborate? > I'd get the M8189 if you > can, because it saves you the hassle of finding boot ROM > and serial cards for the console. Good, as it seems someone found one of these for me. > > What are these intended for anyway (I was thinking of some sort of PMI predecessor, probably > > wrong by now), and what boards do I need to take advantage of them in this machine? > > For an 11/23, those lanes will just go unused. It's not > so bad, really; you have to try pretty hard to fill up 9 > slots. I'd thought so; perhaps I'll happen across some esoteric cards that use them, or I'll hack something custom in there. > If it's in > a box labelled 11/23, though, check to make sure someone > hasn't already performed the modification. OK, thanks! Arno

11 years, 6 months

Apple Quicktake camera Windows software?

by wheagy＠gmail.com

I picked up a Quicktake 100 camera this weekend for cheap and am trying to get it working under Windows so I can easily get pictures to my Website, but I am unable to locate the Windows software. Anyone have a link? An hour on Google has yielded little except the driverguide website which was very frustrating. Tks...Win

11 years, 6 months

Looking for Apple Lisa 2/5 parts

by santo.nucifora＠gmail.com

I'm trying to restore an Apple Lisa 2/5 that has been hit with battery corrosion. I'm looking for the following parts, if anyone has any they'd like to sell: - Lisa 2/5 I/O board - Lisa motherboard - Lisa CPU board While I'm at it: - Lisa keyboard - Lisa 1 mouse (the kind with the long button and not the Mac 128 mice). I am primarily looking for working/tested items but I may be interested in something that was not as damaged as mine that is restorable. Please contact me off-list with these or any other parts you may have. I am in Canada and would need to have them shipped there. I'll cross-post this to the LisaList too. Thank you.

11 years, 7 months

9-track alignment (skew) tapes for R/W-head adjustment

by elson＠pico-systems.com

Date: Sun, 7 Apr 2013 00:10:24 +0100 From: Colin Eby <colineby at isallthat.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: Re: 9-track alignment (skew) tapes for R/W-head adjustment Message-ID: <975726A4-6B0E-4EE6-BB5E-B518CAA638B6 at isallthat.com> Content-Type: text/plain; charset=windows-1252 If you don't have a alignment tape, you might try simply creating a /dev/zero tape from a known good drive. No, this won't work. It will only have transitions in the parity channel, all other channels (0-7) will have no transitions at all except at the end of the block (CRC and LRCC). Writing all 1's will have transitions on all data channels AND the parity channel (to get odd parity on each byte). Drives made for alignment with a scope have a resistor summing network that sums the bit detector on each channel. With bad alignment you see a wave with lots of stairsteps up and down the side. With correct alignment, it becomes almost a perfect square wave, with at most one narrow step on the sides. Jon Jon

11 years, 7 months

VAX 11/780

by elson＠pico-systems.com

Date: Fri, 5 Apr 2013 21:58:25 -0400 From: Ethan Dicks <ethan.dicks at gmail.com> I don't remember the RM07. I remember the RM05 (CDC 9766) and the RP07, which I _thought_ was a 100% DEC design (that resembled a white washing machine with no access panels), but I could be wrong about that. My memory may be slipping. We had a 500 MB drive that fits the description, MASSBus only, and just a couple buttons on the front. You had to open the back to flip the circuit breaker off to reset the drive - which I had to do a LOT until they fixed some of the firmware bugs. I THOUGHT the model was RM07, but maybe it was an RP07. I thought RP was for removable disk packs, and the RM was for fixed HDAs. The drive we had was definitely made by Burroughs, it had Burroughs labels on the boards ons other parts inside. I gather it never was very popular due to price, and so I can't find much online. But, I did find one pic with a readable RP07 label and it looks like I remember. We never had to leave covers open on ours, and had no overheating problems, although the HDA did run hot enough to almost burn your hand! We did have under floor cold air supply in our machine room. Jon

11 years, 7 months

9-track alignment (skew) tapes for R/W-head adjustment

by elson＠pico-systems.com

Date: Sat, 6 Apr 2013 14:00:06 +0100 (BST) From: P Gebhardt <p.gebhardt at ymail.com> To: cctech <cctech at classiccmp.org> Subject: 9-track alignment (skew) tapes for R/W-head adjustment Message-ID: <1365253206.48217.YahooMailNeo at web133105.mail.ir2.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 Hi everybody, I had a look through my tapes and found one from Control Data being labeled "Total Service Tape". Does anybody know, if this tape also serves as an alignment tape? I couldn't find any information about that on the Net so far. I used to make my own skew tapes by just writing a program to write out huge blocks (8K or more) of all 1's. That worked fine for using a scope to check the skew. Not sure if a drive diagnostic would accept such a pattern as a skew tape, though. Jon

11 years, 7 months

pdp-11/23 config (was: Re: Qbus identification)

by Arno_1983＠gmx.de

allison <ajp166 at verizon.net> wrote: > The H9275 can be fitted, the standard connecting cables may or may not > match up but can be had made easily. > > I've even put the backplane from the BA32 in a BA11. The form caxtor is > very standardized though the interconnect for power varies with molex or > terminal barrier strips being used. Ah, good data point to have if I ever get into the situation for a similar operation. > Yes, some of the backplanes and the cpu board have jumpesr that need to > be correct and matching. Alas I don't have any DEC Processor and Peripherals Handbook covering QBUS in dead tree format, just UNIBUS stuff which is of about zilch use to me in this case, but I got myself the BA11-N (which includes details on the backplane) and KDF11-BA manuals from bitsavers. Yes, I also already perused them to a certain extent, and yes, I was aware of the jumper issue (which is why I even _mentioned_ it. Duh.) > I have full sets spanning the years and it fills about 5 ft (1.5M) of > linear shelf space. I consider > them as more important than the hardware. While much of it is on the > net I find it harder to > scan for a specific item like the default jumpers for DLV11J. The books > have a bit of wear > from actual use. Not having worked for DEC and being a bit younger than most of the hardware in question, I'm not that lucky. I could get myself some doubles that were culled from a university collection ('76 peripherals manual, 11/45 and 11/60 processor manuals...) which unfortunately do not cover the era and range of hardware I'm dealing with here. > [boot rom / mass storage issues] I'm not yet holding the CPU card in question in my hands so I don't know the exact variety. I have RL01 (three) and RL02 drives (one) which I would like to use with this system, as they seem appropriate for the era. > The only common card set that depends on CD is RL11 The two board > RL01/02 controller > and it's only 18bit capable, if you working with 22bit system (fully > populated with ram) > then you need the RLV21 which is a single quad board and works in all > backplanes... > > oh and also RL02 drives, a 40" rack minimum, plus a good back! ...not to mention at least one good _pack_, which is (for the RL01) what I'm missing. > In the end the whole Q22 this is only an issue when you exceed 256Kbytes > of memory > as the Q22 allowed the MMU to reach 4MB of ram. I will also be provided with a 512kW MOS memory board, so I will need 22-bit addressing to take full advantage of that, and therefore the (22-bit clean) RLV_12_ single-board controller. So no CD lanes needed here. > PPS oh, I have at least two that have all slots filled! Its way to easy > to plug in IO. > For example RLV21 quad width, RQDX3 dual, TKQ50 (dual) TK50, > RXV21 (dual) RX02 drive controller, DZV11 serial IO(quad), > LPV11 parallel printer (dual), DEQNA (dual), > full 4mb memory (3 quad boards). don't forget the CPU, > 11/23B+ also a quad board. > Thats 16 slots filled plus two grant cards total 18 making a full box. > The grant cards allow for optimal board placement and are required to > keep the DMA and interrupt vector chain complete. Was it indeed usual to build such large configurations based on an 11/23 back then? TQK50, DEQNA and RQDX3 at least sound sound a bit anachronistic to me, there surely must have been newer and more powerful processors out at the time those became available? I think I'll have a rather minimal system (KDF11-B, 512kW RAM, quad SLU, RLV12 + one or drives) for now, not making my first foray into pdp technology more complicated than necessary. Arno

11 years, 7 months

9-track alignment (skew) tapes for R/W-head adjustment

by p.gebhardt＠ymail.com

Hi everybody, I had a look through my tapes and found one from Control Data being labeled "Total Service Tape". Does anybody know, if this tape also serves as an alignment tape? I couldn't find any information about that on the Net so far. I've been trying to resurrect one of my Fujitsu M2442AC tape drives. Even with heads cleaned,it fails the diagnostics when it comes to writing and reading a tape. It turned out that the drive head being held by a plastic plate was loose due to the plastic plate being broken. I tried to glue the plastic together, mounted the head back into its position, but the drive diagnostics still fails (error: F300 ). Azimuth-adjusting the head after remouting obviously needs an alignment tape. Having quite a collection of reel tape drives, I thought it would in any way make sense to have such a tape for head adjustment procedures, but they some to have become pretty rare these days (at least for 9-track 1/2" drives). Substituting these special tapes by any other tricks or ways seems not to come close to the alignment precision obtained wich alignment tapes. Thanks for any help in advance ! Pierre ? ------------------------------------------------------------------------------- Pierre's collection of classic computers : http://classic-computing.dyndns.org/

11 years, 7 months

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test-drb April 2013