test-drb

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101090 discussions

by bqt＠update.uu.se

On 2014-01-27 23:55, Ian King<IanK at LivingComputerMuseum.org wrote: > RK05 drives are hard-sectored, as you mention. RL02s are not, and the > same packs will work on either. The only hard constraint is RL01 vs. RL02 > - you can't use an RL02 pack in an RL01 or vice versa. -- Ian K7PDP True, with a caveat. You can modify an RL02 drive to be capable of reading both RL01 and RL02 packs, but it requires a hardware hack. When I worked at DEC, we had such a drive. However, an RL02 drive cannot reliably write RL01 packs. Johnny

11 years, 5 months

pentium 1 boards

by rmx44＠aim.com

i wonder if anyone out there might have an old pentium 1 board since i have a few pentium 1 processors and even an amd k6-2 but i want to be able to use the processors and maybe build up a nice old windows 95 box or something nice. if anyone might have any just let me know

11 years, 5 months

Antic episode 7 now out!

by dm561＠torfree.net

----- Original Message ----- Date: Mon, 27 Jan 2014 15:44:33 +0000 From: Liam Proven <lproven at gmail.com> Subject: Re: Antic episode 7 now out! > ...If someone appears in one of those corners and top-posts everywhere, > they badge themselves as a clueless newbie who couldn't be bothered to go > to the minimal effort of learning how things work and how to participate. > This person is therefore very unlikely to be a useful member of that > community; in fact, they're more likely to worsen the signal:noise ratio > and thus contribute to its decline.... --- Reply: --- I happen to think that what actually "worsens the signal:noise ratio and contributes to a list's decline" is folks who feel the need to repeatedly comment publicly on hoary old topics like this one and insult people who have a different perspective, knowing full well that it will inevitably derail the original thread and generate a number of off-topic posts like this one. Some quite clever and useful people find top-posting more efficient; get used to it! And if your purpose really was to 'educate' the OP instead of just being rude and insulting in public, why not do it off-list.

11 years, 5 months

Using two RL02 drives on OS/8? (cont'd)

by charlesmorris800＠centurytel.net

>It's working again! > >I made a new RL02 pack using vtserver on my other machine (11/23+), which takes a while to transmit 7.8 MB even at 19200 baud, put it in the 8/A drive 0, held my breath, flipped the boot switch... and got the "." prompt on the terminal :) > >So the problem that started this whole mess was an IDC connector that I had improperly crimped, inside one of the RL02 drives, so that I could run ribbon cable to the RL8A instead of buying the expensive BC80xx cable. Lesson learned. Bought a BC80J-20! > >That short circuit was somewhere in the write data lines, which apparently then wiped out the OS/8 pack so it wouldn't boot any more. > >Lastly, my incorrectly seated quad extender card was introducing errors even after fixing the cable problems, and I wasted several hours chasing that... I may invest in a hex-height extender card to avoid this problem in the future! > >On the other hand, I now have a serial interface on the desktop PC from which I can download programs direct to the 8/A. The next thing is to learn how to use Philipp Hachtmann's KL8E in FPGA to download through a laptop USB port at high speed. It looks like I can just change the few IOT instructions of the RIM and BIN loaders to match the card's switch settings. Trying to get Windows to put binary files out a USB port will be more fun, I'm sure. > >Meanwhile, back to the original problem! My build of OS/8 does not recognize that there are two RL02 drives in the system... which is how I think this thread got started in the first place quite some time ago :) > More info. OS/8 is running on Drive 0. I am able to use RLFRMT (or RL2FMT) to format the pack in Drive 1 (and it does not access or overwrite Drive 0)... so at least SOME part of OS/8 recognizes that there are two RL02 drives! BUILD defaults to DSK=SYS if SYS is not changed. BUILD showed initially DSK=RL20:R2A0 which is indeed the same as SYS. However, if a SYS command is issued during BUILD, according to the manual when issuing the BOOT command it is supposed to ask if you want a new DSK or not. This does not happen - it just says "SYS BUILT" and goes back to the dot prompt. I found that I can manually type DSK=RL21:R2A1 in BUILD and it accepts that without error. Then a "SAVE SYS BUILD 0-7577, 10000-17577=0;200" per the manual. At that point, rubbing BUILD again shows DSK=RL21:R2A1. OK so far. But when I ask OS/8 for the directories of each partition on RL21: (R2A1, R2B1, R2C1, R2D1) what is displayed is the corresponding directory of RL20: (R2A0, R2B0, R2C0, R2D0)! The Drive 1 light never flashes. RESORC shows the following: (6442) 37* (6542) 37 (6642) 37* (6742) 37* (6443) 37* (6543) 37* (6643) 37 (6743) 37 OS/8 V3T so it looks like there are eight different partitions in RESORC, although not all of them have an "*" (does that mean the same "active" as it does in BUILD)? I'm wondering if DSK is, in fact, *not* being changed to the other drive - but then why is there not an error when attempting to get a directory of, say, RL21:R2A1 if it still thinks I'm accessing RL20:R2A0? This has me stumped. Any OS/8 gurus, please help :)

11 years, 5 months

NEC uPD7201C Datasheet, Pinout?

by holm＠freibergnet.de

Hi guys, I've looked trough my Z80 Stuff some minutes before b'cause a friend wanted an Z80A CPU, ok found it. In a Bag 6 uPD780-1 which are also Z80A's, I found two uPD7201C. I've googeled some time before that the uPD7201A is some Z80-SIO - alike, has an other Pinout for example and should be compatible to some Intel chip which is mostly a clone of the Z80-SIO also. (maybe to give the Intel world acess to a usable USART to this time) But: I can't find a datashet for the uPD7201C using google or the usual suspects, can someone help out here? I think possibly this isn't just a different letter, maybe it means that this is the Zilog compatible Version with the Zilog Pinout? Does anyone know something about it or has a datasheet? Next interesting thing are 10 pcs. of NS405-B18N, a sticker says that that are display processors, someone knows where tehy where used in? Kind Regards, Holm -- Technik Service u. Handel Tiffe, www.tsht.de, Holm Tiffe, Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583 www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741

11 years, 5 months

Disk read issues on track 0 with OSI 4P

by philip＠neoncluster.com

Hi all, I've been struggling with getting my Ohio Scientific + MPI floppy drive system working for almost 2 years now. It's been by far my longest 'on and off' project, and in the process I've all but rebuilt the entire drive. I have been using a program for the OSI called DISKREAD which basically just dumps what data it reads from the disk to the screen. Up until recently I wasn't having much luck seeing anything meaningful, but after some more playing around I was finally able to see some data from an OSI boot disk that indeed looked good. I was able to cross reference what I was seeing against a disk image I downloaded off the net, and from track 1 onwards the data looks identical. The problem is track 0. Track 0 contains the boot code. When I dump track 0 it just looks all screwed up, mostly lots of 00's and FF's and F1's and FD's etc etc...basically stuff that just looks wrong. It also seems that doing subsequent passes over track 0 dumps different data each time!!!! I was just wondering if anyone knows what would cause track 0 to read bad and inconsistently, where other tracks seem to read good and consistent? Thanks for for your time. Phil

11 years, 5 months

Philips P850 for sale in the Netherlands

by hp-fix＠xs4all.nl

Not mine, but from a friend. He has for sale a Philips P850 Processor with manuals and some peripherals (tape reader and puncher) If anyone is interested please contact me off-list for further details. -Rik

11 years, 5 months

Compaq CGA card, schematics?

by phil＠viscom.net

Dave, > If the internal screen is fine then the syncs are at or close to the > proper frequency, so any problems are going to be around the NTSC > modulator, which would be fun to debug without a scope... I do have a scope- poking about down in the chassis is difficult- I don't have an ISA extension card. The composite trace drops down to the back side of the card, comes up through a resistor, goes to the light-pen header, through another resistor and vanishes into the middle layer. I could start just prodding with my meter to see where it re-surfaces... but, well, yeah. A schematic would make that easier. The image on composite "tears" horizontally. I made a video of it, hooked up to my TV set in the living room: http://youtu.be/a4jcKiSwUos > On the other hand whilst I have never tried the Composite on CGA, but I > have tried comparable modes on several other computers, including my > rather old Atari STE, and a very modern Raspberry PI and it sounds like > its working (almost) just fine. The composite out on CGA cards always > was pretty useless, and "legible, just" pretty much describes any > 80-colum output on composite. Try 40 a column mode (2 or 3)... That's in 40-col mode, above. In 80-col it goes into a text mode rather like MDA, which I haven't scoped to see if it's not present at the jack, or if the TV refuses to display it. It's remarkably crisp, considering. On a regular TV set (older, cheaper, no-name set)- http://www.flickr.com/photos/philandrews/8657681921/ Above was trying to display this- http://www.flickr.com/photos/philandrews/8660917851/ Admittedly that was all unbalanced, but I'm sure it should be a little better than that. > (Oh and my experience is with PAL, NTSC would probably be worse.....) > If you have a TV with a SCART then the circuit below would work.. > http://www.electroschematics.com/377/ > but I guess you are in the US and and your TV will have CYMG inputs. > Actually that circuit would probably work with CYMG but the colours > would be wrong. Yeah, I should have said. I moved out here to the States a number of years ago now. My TV sets have all the usual "modern" inputs for here, CATV (NTSC modulated), Composite-in, YPbPr component, HDMI and the one in the bedroom has a VGA-in. > If have a modern LCD TV with a VGA input you could try something > similar, but leaving the syncs separate and feed it into the VGA. This > might sound daft but often LCD TVs will sync to normal TV on the VGA. IT > doesn't work with monitors, but it does with some TVs. As a quick and > dirty test you could just use 470 ohms on all leads and omit the "I" > line.... I can give that a try, but it's a band-aid to the symptom. I've got another machine with CGA out and the TV displays it nicely. I'd like to be able to use the composite-out because the machine has several games on that make use of the timing inconsistencies in NTSC to create a larger color palette than the standard 4. That would, however, be useful for other applications. It's been a while since I've seen a SCART connector..! > Dave > -- > Dave Wade G4UGM > Illegitimi Non Carborundum

11 years, 5 months

cctalk Digest, Vol 125, Issue 13

by seefriek＠gmail.com

On 01/05/2014 10:01 AM, Liam Proven wrote: >So perhaps this explains the fondness and elitism about HP calculators >and RPN: that they are good for programmers. Probably 75% of the people I went to business school with (at a University not know for programming or technology, and there was no programming requirement) had HP-12C's, and most of the professors would pointedly not bother to accommodate those that cheaped out and got a non-RPN calc (usually some ridiculous TI graphing model). My brother went to a different business school a couple of years later; same thing. Even though I have stupid amounts of computing available to me, there are all sorts little financial calculations that are essentially muscle memory on my 12C. The 2 mortgage closings I've been to in my life featured lawyers double checking the financial details using HP calculators (one old school HP-37 or -38, one a tricked out HP-41 with the finance ROM). Lawyers, not programmers. My last 2 CFO's kept a 12C within arms length, and I've watched both pick them up and check the details of some deal. Not programmers. The love of my life in my 20s was a radiation physicist, and she and every single one of her colleagues carried an HP-41 with the nuclear medicine pack. Not a programmer amongst them. My current wife is a medical practice manager. Their lead radiologist has the same setup in his office, and he uses it to double check what the computers are telling him about exposures and such. Not something you want to screw up. Also not a programmer. I had to have my lot line professionally surveyed recently, and the guy who did it took all his measurements and then whipped out an HP calculator. Who knew there's a surveyor pack? He said that the surveying gear has all the smarts to do the calculations built in, but he liked to double check because he's found bugs in the gears calculations but never the HP, and he doesn't like to get screwed by filing incorrect reports. Need I say, not a programmer? I could go on. How about an alternative world view: people like RPN and HP calculators because they're the right tool for the right job. All anec-data, of course, much as you've offered. But I understand your personal perspective; when you're half-assing your way through a degree (or task, or career, whatever) you don't much care about and probably aren't much good at, you use tools that are the shortest short-cut to getting some task done, minimal effort, instead of taking time to learn tools that up your game. The world is full of second (third?) rate talent. But taking what you're doing seriously and learning the tools needed to exceed isn't always "elitism", it can just as well be professionalism. Just like it isn't "elitism" to make an effort to be accurate, factual and impartial in other professions, instead of sloppy, biased and condescending. YMMV. KJ

11 years, 5 months

Odd Commodore 64 Question

by healyzh＠aracnet.com

Does anyone have any advice on how to take a photograph and display it on a Commodore 64? I have a rather crazy art project in mind. Zane -- healyzh at aracnet.com http://www.zanesphotography.com http://www.flickr.com/photos/zanes-photography/ https://www.facebook.com/ZanesPhotography

11 years, 5 months

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test-drb