test-drb September 2008

test-drb@ccmp.vtda.org

220 participants
323 discussions

HP9836C colour alignment (grey scale tracking)

by ard＠p850ug1.demon.co.uk

I am working on an HP9836C, in particular the colour monitor part. The original problem looked to be slight misconvergence, with red fringes. But I think it wasn't really convergence problems at all. I've been looking at the video amplifier PCB (the one at the back of the CRT) which not suprisingly contaisn 3 identical video amplifiers along with a blanking amplifier and components to pass the correct voltages to the CRT electrodes. Anyway, there's a resistor in each of the amplifiers that according to the colour bands should be 12.4k. In the green channel it's close -- 12.7k. In the blue channel it's nearer 17k, and in the red it's open-circuit. And I think this could be messing up the HF response of the red amplifer, hence the fringes. The problem is that if I replace it, I'll have to set what HP call 'colour alignment' and what I grew up calling 'grey scale tracking'. I've read the offical HP procedure (if you're interested it's pages 134-138 of the pdf service manual on http://www.hpmuseum.net/), and there are at least 2 problems The first is that I don't have a suitable photometer. The second is that even though it claims I need this photometer for the gain adjustment, the cutoff adjustments are done to 'barely extiguish the raster' I've worked on enough monitors to know that that's not precise at all, so I am wonderign just how accurte the photometer _really_ needs to be. Has anyone ever done this setup and can offer any tips? -tony

15 years, 6 months

Closed vs. open source timeline.

by andy＠smokebelch.org

So whilst the GNU project was announced in 1983 I've heard many examples being cited of the source to software being shared prior to this, E.g. IBM's VM up to vN.N. And indeed recall reading somewhere that up until a certain point in time the source to most if not all software was available. As vendors made their money from hardware sales and you were unlikely to be able to buy a clone or build a machine yourself, and so safe-guarding source code was not a major concern. Does anyone know if the history of closed/unavailable vs. open/available source is documented anywhere? Ideally in a book or journal that can be properly referenced. Regards, Andrew ---------------- Andrew Back a at smokebelch.org

15 years, 6 months

Help with PDP-11 Unibus Map Hardware / Software under RT-11

by jhfinedp3k＠compsys.to

Hopefully, this request is clear enough to be understood. Both the software and the hardware portion of the questions are independently important, so please answer one aspect even if you can't help with the other. Over the past 30 years of using PDP-11 software (RT-11 over 95%) and hardware, I have never had occasion to use a Unibus system with more than 256 KB of memory (such as a PDP-11/34). I would appreciate help in understanding the Unibus Map hardware which (if I understand its purpose correctly) is to convert 18 bit addresses given to a Unibus controller into 22 bit addresses for real physical memory for systems like a PDP-11/84 and perform DMA from / to the hard drive. Also helpful would be an explanation of the related software used under RT-11 along with exactly where the Unibus Map hardware is located on a real DEC system (on the CPU board I presume) since the identical CPU board is used for both the Qbus and the Unibus with both the PDP-11/84 and the PDP-11/94. ------------------------------------------------------------------------- DO NOT READ THE FOLLOWING if you don't use RT-11!!!!!!! By way of context, I have successfully modified the HD0: device driver originally written by John Wilson which obviously executes ONLY under E11. Last week, John mentioned in a private e-mail that it is possible to direct the HD0: "controller" (all references to hardware in quotes refers to E11 software) to ignore the "Unibus Map hardware". Since I execute under E11 using Qbus emulation in order to stay totally compatible with the real DEC PDP-11/23, PDP-11/73 and PDP-11/83 systems (all Qbus and all with 4 MB of physical memory) which I have available for comparison testing, user buffers in physical memory above 256 KB are often a situation which can't be avoided. Consequently, it had always been a high priority to have a 22 bit device driver for HD0: under E11 BECAUSE HD0: is TWICE as fast as MSCP (DUX.SYS device driver). In addition, I have also been able to write code that avoids the overhead of using the HD0: device driver which makes HD0: FOUR times as fast as MSCP and also allows for direct access of 2 TB of disk space via a 32 bit block number. Since I have an immediate application for a data base of 32 GB (I have a disk drive of 160 GB, so 32 GB is only 20% of its capacity - although under RT-11 15 years ago in 1992, 32 GB would have been only a dream), the code which I have written will actually be used quite soon. However, I would very much like the HD0: device driver to be able to execute under both "Qbus" and "Unibus" hardware. And while I can test the code for a "Qbus" and for a "Unibus" without a "Unibus Map", I am not clear about what is required for a "Unibus" with a "Unibus Map" such as a PDP-11/84 running under RT-11. Megan are you still watching the list? Allison, if you can't answer, can anyone but Megan help? Is anyone else familiar enough with the "Unibus Map" that you can suggest what RT-11 actually needs to do with the "Unibus Map"? A solution is to check the "hardware" configuration and refuse to allow the HD0: device driver to LOAD or .Fetch if the modified version is not executing under "Qbus hardware". By the way, if anyone who is thinking of a controller for the Qbus which is able to use SATA drives, I would be happy to modify an RT-11 device driver to an HD0: type device that is able to handle drives up to 2 TB in the same manner that DU(X).SYS can handle drives up to 8 GB. Anyone interested?? Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.

15 years, 7 months

Making an RT-11 boot disk

by dbetz＠xlisper.com

I'm trying to use simh to create an RT-11 bootable RX50 disk and am following some instructions posted by Megan Gentry a while ago. I've created the disk image but am having trouble making it bootable. The copy/boot command claims it can't find the RT-11 image but it is clearly on the floppy (du0). Any idea what's going wrong? .dir du0: 10-Apr-99 RT11XM.SYS 106P 20-Dec-85 DU .SYS 8P 20-Dec-85 TT .SYS 2P 20-Dec-85 PIP .SAV 30P 20-Dec-85 DUP .SAV 47P 20-Dec-85 DIR .SAV 19P 20-Dec-85 RESORC.SAV 25P 20-Dec-85 EDIT .SAV 19P 20-Dec-85 MACRO .SAV 61P 20-Dec-85 CREF .SAV 6P 20-Dec-85 LINK .SAV 49P 20-Dec-85 LIBR .SAV 24P 20-Dec-85 FILEX .SAV 22P 20-Dec-85 HELP .SAV 132P 20-Dec-85 BATCH .SAV 26P 20-Dec-85 FORMAT.SAV 24P 20-Dec-85 SETUP .SAV 41P 20-Dec-85 SPEED .SAV 4P 20-Dec-85 DATIME.SAV 4P 20-Dec-85 LET .SAV 5P 20-Dec-85 SPLIT .SAV 3P 20-Dec-85 CONFIG.SAV 7P 20-Dec-85 SWAP .SYS 27P 20-Dec-85 23 Files, 691 Blocks 95 Free blocks .copy/boot du0:rt11xm.sys du0: ?DUP-F-File not found DU0:RT11XM.SYS

15 years, 7 months

Z80 home brew with FDC

by lynchaj＠yahoo.com

Z80 home brew with FDC Eric Smith eric at brouhaha.com <mailto:cctalk%40classiccmp.org?Subject=Z80%20home%20brew%20with%20FDC&In-Re ply-To=200809220822.16872.thrashbarg%40kaput.homeunix.org> Sun Sep 21 20:02:25 CDT 2008 * Previous message: Z80 home brew with FDC * Next message: Z80 home brew with FDC * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Alexis wrote: > The FDC-1 uses a FD179x controller and it appears it uses the same > data clock and raw data inputs as the 765. Not quite. I don't recall the details of the difference, but I think it may have just been the polarity of one of the signals. The 9229 and 9239 had a configuration input to select between 179x and 765 modes. The 9216 would directly connect to one, and needed a small amount of logic (maybe just an inverter) for the other. > The decoder is made up of a 74LS197 (clock divider), a dual 74LS74 flip-flop, > both used, a 74LS163 counter and an inverter. There are also some open > collector NAND gates to select the clock rate for either 8" or 5.25" drives. > It'll use more individual IC packages, but they're *much* easier to find. Sure, but it doesn't sound like it's a very good data separator. The good ones have a PLL (either analog or digital), because it is necessary to track speed variations, not just of the drive that you're using to read a disk, but also of the drive that wrote it. Non-PLL data separators work OK when the disk is both written and read under optimal conditions, but are unreliable otherwise. The 9216, 9229 or 9239 are *highly* recommended, as they have a good digital data separator. The 9229 and 9239 also contain write precomp logic. The 9239 uses higher resolution timing for its PLL, so it may perform better. ------REPLY------ Hi, Eric is right about the FDC9229 being mode selectable between 179x and 765 modes. It makes a difference in a number of output frequencies, etc. Check the datasheet. It is at the bitsavers.org URL I posted previously. I can't speak to the PLL issue but Eric is consistent with what I have read and heard previously. You can make data separator replacements from TTL but the FDC9229 data separators are really good and provide more than just data separation. They do a whole host of functions such as FDC clock, data window, variable write precompensation, etc. I recommend them and they are fairly easy to work with. They are not easy to find but they are available if you look enough. Is anyone interested in adding a 765 based FDC to their Z80 home brew computer? This design is mostly done and just needs some road testing and another set of eyes to check it out. The software is kind of crude but working. There are only a couple of modifications left on the hardware. First is to attach the FDC9229 write precompensation pins to the latch and second is to connect the remaining two latch pins to FDC interface pin 2 and 34. The hardware will probably get finished this week some time. The software will probably take a while though. Tonight I read and wrote sectors on the IBM PC 360K 5.25" floppy disk. On the same disk, I formatted some tracks so these functions seem to be working in both DD and HD mode. Also verified with Catweasel that the 1.4M 3.5" floppy disk is generating correct tracks. All the sector header information is checking out right it seems. BTW, when working on this FDC project, I cannot say enough good things about the Catweasel. It is like have having x-ray vision into what is being written to the disk and shows all sorts of hidden stuff. Very helpful when you can check independently what the i8272 is doing compared to what it will tell you it is doing. Thanks! Andrew Lynch

15 years, 7 months

LED displays (TIL305, TIL308, etc.)

by ethan.dicks＠usap.gov

Hi, All, Since one of the first computers I ever got my hands on as a kid (Quest Elf) happened to have TIL311 HEX displays, I've long been fascinated with display technology of that vintage. I was poking around for images of some of the related displays to the TIL311 and ran across a couple of links with pictures and some history... http://www.decodesystems.com/old-displays.html http://www.decadecounter.com/vta/tubepage.php?item=33 In particular, I notice that one of the displays I have one of is a TIL305 or MAN2 (no logo on mine). I was also looking at the TIL306 or TIL308, but don't happen to have any of those. I do have a reasonable quantity of TIL311s for my various Elf and Elf2000 machines and even a set that came with an INS8073 SBC. I would love to find a couple more TIL305s so I can round out an old project, plus I had an idea for a project that would be interesting to use TIL306s or TIL308s (don't care about where the decimal point is, so either is acceptable), but ISTR some discussion on the list a while back about those in particular, possibly as replacements to some HP counter, and how difficult and expensive they are to obtain. TIL311s are frequently found on eBay for various prices; I've gotten them myself for as little as $2.50 each in small quantities. I doubt that TIL306s and TIL308s are anywhere near that inexpensive, no matter what the quantity, but I thought I'd ask if anyone has recently found any place selling them. I'm not trying to repair a bit of vintage kit, so I'm not willing to pay "any" price for them - if they are too expensive (as I suspect they are), then I will find some other display. Yes, non-driven LEDs are inexpensive to free and modern microcontrollers can drive wads of LEDs easily and cheaply, but what I'm going for is a 1970s look with 1970s components (i.e., popcorn-logic driven, not micro- processor-driven). The advantage of the TIL306s and TIL308s is now what it was then - a high level of integration reducing the overall wiring complexity and parts count. The disadvantage now as then is that the displays are more expensive than the entire rest of the device. They still look cool, though, and that's the real point. -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 29-Sep-2008 at 22:20 Z South Pole Station PSC 468 Box 400 Temp -71.3 F (-57.4 C) Windchill -102.3 F (-74.6 C) APO AP 96598 Wind 7.6 kts Grid 72 Barometer 683.5 mb (10496 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html

15 years, 7 months

TU-58s (was Re: Some progress with my PDP-11/73 system)

by ajp166＠bellatlantic.net

> >Subject: TU-58s (was Re: Some progress with my PDP-11/73 system) > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Wed, 11 Apr 2007 21:54:24 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 4/11/07, Jerome H. Fine <jhfinedp3k at compsys.to> wrote: >> But I once had a project that >> used a real DEC TU-58. Not the fastest "random" >> access device!!!!!!!!!!!!!!!!!! > >They work better as "sequential" access devices - being long and thin >and travelling in one dimension, go figure. We used to optimize file >order on our console TU58s to speed up the boot times on our 11/725s >and 11/730s. Since the file order doesn't change, one just builds a >TU58 with EXCHANGE with each file following the other. The console's >8-bit-micro must cache the directory block, since the tape didn't whip >back to the start between each file. > >Using unaltered console tapes from DEC resulted in, IIRC, about 15 >minutes from turning the key to booting the hard disk. Replacing that >tape with one of our own devising shortened that pre-boot time to well >under 3 minutes. > >I'd hate to rely on a TU-58 and no other block-addressable media on a >PDP-11, though. I survived a PDP-8 with a TD8E and TU56, but it was >somewhat tedious (cool to watch, though). TU-58s weren't as cool, >IMHO. So happens one of my "small" pdp-11s uses a Tu58. the system is a BA-11V with an 11/23 256k of ram, DLV11J and MRV11 rom(boot). Takes 10 minutes to boot, setup VM: then copy key files to and reboot. After that it's pretty decent even if I have to access a file on tape. Everytime I runs it with a bunch of kids of the current PC generations they go gaga and comment on how slow then I explain the amount of ram and storage then they are amazed it can be a functional machine with so little. They can't imagine a useful machine with 32kW of ram and 256kb of storage. On the flip side I've used that same Tu58 to bring up iron that had no removable storage. It's slow but very dependable. Allison

15 years, 7 months

more Flexowriter

by sturges＠vt.edu

Dear Classics: I just gotta get a Flexowriter. Who has one that will sell it to me? I had one years ago and gave it up in time of crisis. (Yes, I deserve it.) No reasonable asking price refused! Cheers, Dr. Bob

15 years, 7 months

Looking for Norsk Data ND-100 info.

by axelsson＠acc.umu.se

Hi! I'm looking for ND-100 information. A couple of my friends have started to work on a ND-100 emulator and it is progressing fast... fast to a point where we are lacking information about the inner workings of the ND-100 CPU. Specifically we are looking for information on the real time clock interrupt and micro code programming but other information (manuals, schematics or programs) is also interesting. I currently have the following manuals that I'm transforming into pdf:s as time permits. * ND-06.007 BIG MULTIPORT MEMORY SYSTEM * ND-06.014 ND-100 REFERENCE MANUAL * ND-06.016 ND-100 INPUT/OUTPUT SYSTEM * ND-30.003.06A : SINTRAN III System Supervisor * ND-30.025.02 : COSMOS Operator Guide * ND-30.071.1 EN : ND-5000 Series User Guide * ND-40.004.06 : Norsk Data Documentation Catalogue * ND-40.012.1 EN : Information Pamphlet for Norsk Data Customers * ND-60.014.01 : Page III-1-1 to A-9 (some pages missing) * ND-60.046 TRACE ROUTINE * ND-60.047.03A : NORD PL User's Guide * ND-60.050.06 : SINTRAN III Users Guide * ND-60.066.04 : ND Relocating Loader * ND-60.074.01 : NORD-10 FORTRAN SYSTEM Reference Manual * ND-60.088.03 : ND Screen Handling System * ND-60.096.01 : Page 2-16 to D-3 * ND-60.111.03 : ND TPS User's Guide * ND-60.132.03 : SINTRAN III Timesharing/Batch Guide * ND-60.151.02A : SINTRAN III Utilities Manual * ND-60.158.3 EN : SYMBOLIC DEBUGGER User Guide (2 ex) * ND-60.163.4 EN : COSMOS User Guide * ND-60.196.01 : BRF-LINKER User Manual * ND-60.230.01 : SINTRAN III J-version Release Informaton * ND-60.236.1 EN : ND-100/500 SORT-MERGE User Guide * ND-60.264.1 EN : SINTRAN III User Guide * ND-63.001.02 : Introduction to NOTIS-WP * ND-63.026.02 : NOTIS-CALC Handbok (in Swedish) * ND-63.042.1 EN : NOTIS-WP M Release Information for new users * ND Ring binder with cable diagrams * Am201B/Am2901C Four-Bit Bipolar Microprocessor Slice, AMD. Page 5-1 to 5-18 * PASCAL : Instructions in Swedish for running Pascal on ND-100 If you have anything outside of this list please let me know. I will borrow for scanning, buy or trade anything of interest. The hardware we got access to is a ND-100 satellite, two ND-100 racks with disks and 8 inch floppys in parts and a nonfunctional NORD-10 in a rack. When time permits we will try to get it running. /G?ran

15 years, 7 months

LED displays (TIL305, TIL308, etc.)

by dm561＠torfree.net

Date: Tue, 30 Sep 2008 03:48:31 +0000 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Re: LED displays (TIL305, TIL308, etc.) <snip> >I have one or two of a few different types, but no loose 9368s (only >installed in boards already). >One thought I had for trying to use a reduced-pin-count MCU-based numeric >display was a 7447-type chip on 4-bits of an I/O port, and a 74145-type >BSD decoder on the other half of the port - up to 10 digits easily, or 9 >with simple blanking (write 0 to the '145 and don't hang a digit off of it). <snip> >-ethan ----------------------- That's the way it was usually done, although depending on display size (current) a '145 might not have enough oomph to drive the digits directly without a buffer. I have a few 9368s if you're desperate; it decodes to hexadecimal (for common cathode displays), whereas the 7446/7/8 displayed those odd symbols (and blank for F of course). m

15 years, 7 months

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test-drb September 2008