Re: 3d modelling software
On 8/23/21 3:29 PM, shad via cctech wrote: Hello Rob, FreeCAD is nice for modeling 3D shapes. For 3D printing, depending on the technology of 3D printer, you need to process original model to convert compact sections into hollow honeycomb structure, and add small plastic bars into empty volumes to support the model while it's printed. I'm not expert of this latter procedure and tools. Cura does a great job of slicing the .stl model and computing the infill, support, etc. Jon
Re: Help reading a 9 track tape
On 7/30/21 1:02 PM, James Liu via cctech wrote: Hi, I have been lurking for a few years, but thought I'd finally speak up as I just received a 9 track tape purportedly containing the source code to Schoonschip (https://en.wikipedia.org/wiki/Schoonschip). This is a 2400' reel recorded at 1600 bpi based on the labels, and a cursory examination suggests that it is still in pretty good shape (although I am not sure how it was stored over the years). Here is a picture of the tape: https://drive.google.com/file/d/1JgY8QdVDchxubUz39jYn86gEczSvFhcZ/view?usp=sharing We no longer have any equipment that can read the tape, so I was wondering if anyone may be willing to help or if anyone had suggestions on where to go to get it read. Thanks! Where are you? I have a CDC Keystone drive that worked last time I fired it up, and I have it interfaced to a Linux PC. I'm in Missouri. Jon
Re: Intellec MCS-8 8008 monitor program ROM files
On 03/03/2021 07:17 AM, Roland via cctech wrote: Hello everyone, Does anyone have the Intellec MCS-8 8008 system monitor ROM files? According to the Intellec MCS-8 manual the System Monitor is contained in five 1702A PROMs.My ROMs have a disk loader, but the disks system is long gone... Any papertape software is also welcome for this machine! Thanks in advance!Regards, Roland Huisman Wow, I have an old 8008-based embedded device I built back in 1976. It has the MCS 8008 CPU board, 1702 EPROM board and a RAM board. I never had the system monitor, I did everything on that project "bare iron". I think I did development with a PDP-11 and a homebrew cross assembler. Jon
Re: IDE Hard Drive Question
On 06/25/2020 05:29 PM, W2HX via cctech wrote: Does ANYONE have any idea what these 4 wires are connected to and why? And anyone give any odds about whether these 4 wires will prevent this IDE-SD converter from working? Temperature sensor and heater. Undoubtedly for start-up in extreme cold conditions. Jon
Re: PDP8 KV graphics PCB design
On 06/23/2020 12:05 PM, Roland via cctech wrote: I found somewhat fascinating pictures in a PDP8 small computer handbook. It is a KV graphics system. According to the book it was used to design new computer circuit boards. So I got very curious to that KV system. I found a maintenance manual about the system. It even had a joystick! I wonder if any of that PCB software has been rescued? Regards, Roland https://ibb.co/WVKCfMz https://ibb.co/TvYpP2v https://ibb.co/6mSZkdh Ah, yes, a Tektronix 611 direct view storage tube! We also used those on the Artronix PC, they were the only way a 12-bit computer could keep a complex display on the screen without horrible flicker. Jon
Re: Ancient transistor ?computer board (Peter Van Peborgh)
On 06/20/2020 04:20 AM, Peter Van Peborgh via cctech wrote: Guys, I now know it is an early CDC board. IT had C*NT*OLDATA on the reverse - how I missed that must be attributed to old age. (Thanks Doug) Here are shots of the back: https://photos.app.goo.gl/UPozyBB3zp7XYcP79 Ah, the missing letters are covered by solder! Any idea what the row of hole opposite the contacts were? Testing points? Yes, for sure. The way they are made so close to the edge, you can just clip a scope probe to them for testing. Jon
Re: Ancient transistor ?computer board (Peter Van Peborgh)
On 06/18/2020 03:14 PM, Peter Van Peborgh via cctech wrote: Big transistors are Motorola "180376008". Those would be "house numbers" in the customer's part numbering system. Also, any ideas what the "246 636 B" boxes are, they have four legs? Most likely pulse transformers. This might be a core memory sense amp/inhibit driver board. Jon
Re: Ancient transistor ?computer board (Peter Van Peborgh)
On 06/18/2020 03:14 PM, Peter Van Peborgh via cctech wrote: * "C NT OL DATA" on side B (solder traces). Sure looks like Control Data, a major manufacturer of mainframe computers in the 60's and 70's. And, being all discrete transistors, that would likely be late 60's. Jon
Re: SMS Data Gathering App Announcement
On 05/20/2020 10:40 PM, Jay Jaeger via cctech wrote: On 5/20/2020 9:27 PM, Jon Elson wrote: Umm, if it can take ALDs, then (maybe with some tweaking) it ought to be able to do the same for SLT and MST machines, too! That might get a few more people interested in the concept. Jon I doubt it would be easy based on a quick look at an 1130 (1131-C) ALD. OK, these are the sort of issues I expected would be encountered. But, there have been rumors of people trying to do gate-level reimplementations of 360s and 370s so accurate they would run diagnostics and FLT decks without squawks. Such a tool would make a project like that more approachable. But, yes, that's for somebody who wants to do such a project to make the conversion. (I tried to build a quasi-360 in 1981 or so. I built a 32-bit AMD 2903/2910 microcode engine with a Z-80 CP/M as front end and diagnostic console. I got that working at 125 ns cycle time for 2-address instructions, but then realized HOW MUCH work lay ahead before I could actually run a program on it, no less have an OS and peripherals on it. I still have it in my basement. See: http://pico-systems.com/stories/1982.html if interested. ) Jon
Re: SMS Data Gathering App Announcement
On 05/20/2020 09:21 PM, Jay Jaeger via cctech wrote: WOW, what a huge effort! I also spent quite a bit of time generalizing it, so that it will hopefully be usable (perhaps with some more fixes / enhancements / generalizing for most any SMS machine (IBM 1620, IBM 709x, IBM 1401 etc. etc. etc.) Umm, if it can take ALDs, then (maybe with some tweaking) it ought to be able to do the same for SLT and MST machines, too! That might get a few more people interested in the concept. Jon
Re: PDF of FANUC TAPE READER A860-0056-T020 Manual Wtd.
On 05/12/2020 10:36 PM, Bill Degnan via cctech wrote: Following up on the results of my searching around. The FANUC A860 reader with A20B controller (the normal set up) has a 50 pin output port. There is a device one can buy that receives the signal from the FANUC's 50-pin port and converts to into 25-pin RS232. The device is called a behind the tape reader or BTR. There are models of BTR made for FANUC. I found the Memex MX1000 and MX1100, Sanyo RLC174 and DOSTEK 440A. I am sure there are more. 20+ years ago, I resurrected an Allen-Bradley 7320 CNC controller. I didn't want to deal with paper tapes, and had to modify the program a bit, anyway, and had no punch. So, I built my own BTR. The interface on this one was a 12 V logic standard, but quite simple. 8 data bits and a strobe came out, and there was an input to advance to the next character. (These old CNC controls had bi-directional readers, and the control could move forward and backwards on the tape. But, I didn't need the reverse feature.) It was a pretty simple thing to set up and connect through the computer's parallel port. Jon
Re: PDF of FANUC TAPE READER A860-0056-T020 Manual Wtd.
On 05/12/2020 11:10 AM, Bill Degnan via cctech wrote: Turns out the "The Director" tape reader I purchased last week was defective and I got a refund. So I thought I'd try my hand at the FANUC TAPE READER A860. I may need to make a serial cable (?) to connect from the internal connector don't know yet. Or maybe the internal 50-pin port from the photos is for the punch. Don't know yet, thus the need for the manual. I checked bitsavers.org but there was no manual there, anyone here have a PDF or URL of the PDF for the FACIT tape reader A860-0056-T020? A860 is a Fanuc part number, not Facit. So, if Facit made the reader, you should look for another part number somewhere. Fanuc, way back when, did make excellent manuals with full schematics, so there might be a schematic available somewhere in a huge book of Fanuc schematics for that vintage machine. but, you'd need to know about what vintage of Fanuc to look for. Jon
Re: Wanted, Papertape Reader for Archiving Tapes
On 04/28/2020 11:01 AM, Bill Degnan via cctech wrote: Hi - COVID project I have been attempting to read some old Honeywell DDP-516 papertapes using the OP-80A or Teletype reader but it's inefficient and I don't want to damage the tapes. Does anyone have a reliable papertape reader for sale I have a slightly damaged EECO reader with take-up reels. The damage is one of the spring arms is snapped. It could be repaired fairly easily, or used without the reels. it has a 12-V parallel interface, apparently called RS-408. It is from an Allen-Bradley CNC control computer. I could let it go for $50 plus shipping. it is a fairly large rack-mount unit. Jon
Re: Nixdorf computer AG boards rechner 154
On 12/20/2019 02:53 PM, Adrian Stoness via cctech wrote: weird nixdorf is the last name of my boss whos in his 70's engineered lime plants around north america for what became greymont No, Nixdorf was a significant player in the computer business in Europe, especially. Wikipedia says they were the 4th largest computer maker in Europe at one time. Jon
Nat Semi MM5262N available
I have about 240 pieces of the national Semiconductor MM5262N 2K x 1 DRAM chips. They appear to be unused, in aluminum (not plastic) tubes. Chips are plastic packaged. 365 ns access time, 475 ns read cycle. Anybody need them to fix an old computer? Jon
ECL static RAM ( 10144L)
I have 400 pieces of Signetics 10144L ECL static RAM chips. Anybody need some? These were salvaged from boards by a surplus dealer (Alltronics, I think). They are a 256 X 1 bit RAM, somewhere around 20 ns access time, ceramic package. Jon
Re: SGI Challenge M memory boards
On 10/02/2019 12:18 PM, Dennis Grevenstein via cctech wrote: Hi, Jon wrote: I have 15 pieces of memory SIMMs for the Challenge M series (funny, seems like there should be an even #). Pics here : http://pico-systems.com/images/SGIChallenge.JPG A Challenge M is basically a server variant of an Indigo2. What you have looks like memory for a Challenge L or Onyx. OK, it was some time ago, it well could be a Challenge L. it was a big box, and was powered by a big 28 V power supply. (Or, was it a 48 V supply?) Jon
Re: Pertec Interface Cable Length
On 08/11/2019 08:00 PM, Douglas Taylor via cctech wrote: This is where the electrical engineer could help. How do you determine how long a cable the 74LS240 can drive? Well, there are several considerations. First, it takes some current to charge up the cable capacitance. More current charges the capacitance faster, but also creates faster edges which cause more crosstalk. Then, the data rate needs to be considered. Mag tape data rates are not that high. So, for 1600 BPI at 45 IPS, the data rate is 72 K bytes/second, or about 14 us per byte. Twisted-pair cable should have a little less capacitance, and it is supposed to reduce crosstalk, so should work better. The most serious problem is when many data lines switch at the same time, it may contaminate the clock pulses and cause bytes to be dropped or added. With the low data rates involved, proper delays to allow ringing to settle on the data lines and prevent short crosstalk pulses from affecting the clocks should make the system very tolerant of cable issues. But, maybe some engineers didn't really optimize their logic for these problems. Jon
Re: Pertec Interface Cable Length
On 08/11/2019 11:11 AM, W2HX via cctech wrote: I seem to remember they were ribbon cables with each odd/even pair twisted which probably meant one active and one ground twisted together. Or differential pairs. No, both Pertec unformatted and Pertec formatted interfaces were TTL single-ended. Jon
Re: Pertec Interface Cable Length
On 08/09/2019 11:05 PM, Douglas Taylor via cctech wrote: I have a question about cable length - any electrical engineers in the house? Connected a Qualstar 1260 tape drive to an Emulex TC02 qbus tape controller in a pdp-11/53. The interface is pertec with 2 50 pin cables. When I use a pair of short flat ribbon cables, 18 and 30 inches each, it works. Under RT11 I can INIT, Copy, DUMP, do a Directory. It doesn't work when I use a pair of 5 foot long flat ribbon cables. Are they too long? Do I need twisted pair type of cable? Is it possibly a termination problem? I have used cables about 20 feet long without trouble. The 2 50-pin cables is the Pertec formatted interface, which is really forgiving. Does you drive have terminators in both ends of the cable (both at the TC02 end and the drive end)? Now, I will mention that I have ONLY used twisted-pair ribbon cables with both flavors of interface, never straight ribbon cable. Jon
Re: Greetings
On 04/29/2019 06:47 AM, allison via cctech wrote: On 04/28/2019 09:28 PM, Grant Taylor via cctech wrote: On 4/28/19 6:27 PM, Ray Jewhurst wrote: I already have a Hobbyist License. I am just interested in experimenting with different OSes and different versions of OSes. ACK I don't know what VAX hardware VMS 1.5 supported, what VAX hardware that Simh supports, or what the overlap is between the two. There's a reasonable chance that someone will chime in with experience. You are limited to what the VAX-11/780 system had for peripherals and typically under 8MB ram (it maxed at 16mb). Well, for command-line computing (well, this IS the classic computing list) you can do a lot. Our first 11/780 had half a megabyte of memory. Friday afternoon one memory board went bad, and I pulled it out. A user group ran a gigantic batch job of mechanical analysis over the weekend on 256 K! I was amazed, I really thought it would thrash itself to death on that. I ran a microVAX-II at home on one meg for years. But, I never experienced VMS before about version 3.4, I think. I'd really hate to run any VMS that didn't have loadable device drivers. Doing the brute force sysgens was so RSX-11 ish. I think VMS 1.5 still had a bunch of utilities running in PDP-11 emulation. Jon
Re: Core memory emulator using non volatile ram.
On 12/15/2018 11:19 PM, Rod G8DGR via cctech wrote: However I began to think would it be possible to create a close copy of an 8/e out of modern parts. Finally the big one – Omnibus and the connectors its made from. A 3D printing candidate? I’m going to autopsy a busted connector and see how they are constructed inside. Yup, this will be a problem. A couple decades ago, there was a very common technology, press-fit backplanes. You made a PC board with all the interconnect on it (power + signals) and pressed-in contact fingers. Then, connector housings were pressed onto the contacts. I don't know if anybody still makes these contacts. It would be hugely expensive to have custom ones made, but if they are still being made they might not be too bad. I'm not sure 3D-printed housings would be strong enough for this, but maybe if ABS they would. Of course, there might actually still be somebody making clones of the DEC connectors. They used basically the same design for PDP-8, PDP-11, KL10, VAX, etc. Certainly, there were people cloning them back in the 1980's. Winchester made the official ones for DEC. Objectives The basic board set as original. M8300, M8310, M8320 etc. Same form factor Plug compatible – but board contents can differ from original Well, this could all be done with one FPGA, but if you want to do each PC board separately, a modest CPLD or small FPGA would certainly do each board's functionality. Jon
Re: Working Ardent Titan on Youtube
On 11/26/2018 09:16 AM, Camiel Vanderhoeven via cctech wrote: I still have one remaining issue, and that is that when I connect the system to my network, it works (I can ping both ways), but the OS becomes unstable, and usually crashes within a few minutes. Perhaps it has a problem with jumbo packets or something like that. You might need to put a firewall between it and other systems to isolate it from newer ports/traffic that it doesn't understand. (Just a total guess.) Jon
Re: Working Ardent Titan on Youtube
On 11/25/2018 08:42 AM, Camiel Vanderhoeven via cctech wrote: Now that my mousepad problem has been solved, and I have a fully working Ardent Titan with some interesting software on it – the bundled version of MATLAB, and BIOGRAF, a molecular modeling application – I decided to make a short video about this system in which I show the hardware and demonstrate some of the software: https://youtu.be/tMSnnt3iFz0 WOW! Just wow! That is pretty impressive, but for 1987, it is truly awesome! Jon
Re: Info needed: CMI 1600, CDC Omega/480, IPL Systems, Olivetti 5300
On 07/18/2018 03:15 PM, Johannes Thelen via cctech wrote: Anyone familiar with these PCMs? I got a CMI 1640 and little help needed. Here's photos: https://drive.google.com/drive/folders/1w74AYe6lRSn9gJhyKVlBYAq5zRDWybSw?usp=sharing What this 370 clone is exactly? If I have understood right, Steven Ippolito's IPL Systems Inc developed the original machine and CMI (Cambridge Memories Inc) made them. Also these sold as Omega/480 and Olivetti 5300 series. Later CMI made their own versions and I believe this one of those. But I haven't found model 1640. So is this 1641..? What is difference between CMI and others? Microcode? I got belong with the machine a couple manuals, Maintenance and Theory of Operation. Unfortunately original microcode disk is missing (and 8" drive...), so that would be needed if I ever want to fire this thing up. Any ideas where I could find a one? Wow! solid state memory and ECL chips for the CPU! Going to be real hard to find the missing items unless somebody who worked with them hid them in their garage. Anyway, such a machine is pretty useless without a bunch of peripherals. You'd need a disk control and drives and a comm control to be able to do much of anything. Jon
Re: Modifying microcode
On 06/02/2018 03:33 PM, Antonio Carlini via cctech wrote: On 02/06/18 15:17, allison via cctech wrote: It was my understanding from using the 730 that there was limited (really limited) microcode enough to load the WCS as the tu58 was a serial device (standard tu58) and the 730 had to unpack and stuff the WCS. You need little to do that but far from even PDP11 instruction set. The Microcode was loaded was the "what made it a VAX stuff". Allison Well something has to load the ucode but whether that's a fixed part of ucode itself or whether it's a hardware state machine (or something) that feeds the loaded ucode into the appropriate RAM, I don't know. I've never delved that deeply into the relevant FMP sets. Actually, the 8085 could load a small bootloader from 8085 ROM to the 730 microcode. That would be the most logical way to do it, assuming the microcode bootloader was really small. The IBM 360/25 had all microcode in the top 16K of main core memory, and the emulator of your choice could be loaded from binary punch cards. The microcode bootloader was hand-loaded through the front panel switches, and occupied 16 16-bit words. Jon
Re: Any difference between VAX Q-bus and PDP-11 Q-bus cards?
On 12/03/2017 10:28 AM, Aaron Jackson via cctech wrote: I'm looking after a VAX 4000 for a friend, which has a SCSI Q-bus card (M5976). If the card did not have the large metal face, would it work in a Q-bus PDP-11? We are not going to potentially ruin a card by trying this, but I am interested to know if this is the case. As long as the PDP supports the 22-bit Q-bus, it should work perfectly. The metal plate can be removed. Jon
Re: PDP-8/a wire-to-board connector for power?
On 11/03/2017 08:52 PM, Brian Walenz via cctech wrote: Awesome, thanks! I missed that in my scan of the Mouser catalog. https://www.mouser.com/ProductDetail/TE-Connectivity/1-480270-0/ $0.86 for the connector, $160 for the crimper. You should be able to use Molex crimping tools with these contacts with a little care. The contacts are quite similar. You can even use needle nose pliers, but you will end up mashing more than you crimp properly. Then, you will need to solder them to get a good connection. Jon
Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]
On 10/02/2017 08:29 AM, allison via cctech wrote: It was price... ATA-IDE was cheaper and PC industry was working hard to push the price down. SCSI always remained more costly. Yes. I think there were royalties to pay for a true SCSI drive. Anyway, there was a VERY significant price difference between early IDE and SCSI drives. Several hundred $ for a similar capacity drive. Jon
Re: Unknown boards
On 06/16/2017 09:31 AM, David Gesswein via cctech wrote: Can anyone identify these boards? Person I got them from can't remember anything about them. http://www.pdp8online.com/ftp/misc/unknown_boards/ Date codes of 1964. Size 4.5"x3.25". Looks like used card edge for keying but has separate 23 pin connector for electrical connection. No useful markings I can see. Has card ## on the back. Search by picture didn't find anything. Thanks They remind me of RCA bizmac boards, which are likely to be related to GE, as that computer division changed hands a number of times. The connectors are Elco Varilok. Jon
Re: rectangular sense core vs. diagonal
On 06/07/2017 09:12 AM, william degnan via cctech wrote: Where there any computers that used a "rectangular sense" core RAM? Whirlwind core is diagonal. This page describes the differences/evolution of the sense line. More: http://ed-thelen.org/comp-hist/Byte/76jul.html Were rectangular core planes used in any commercial/government computer that saw production activity, presumably the period 1953-1959?Whirlwind is known for diagonal sense planes, but was there a brief period when the core was "rectangular sense" I know core was added to Whirlwind as an upgrade, it did not launch into production with core. (right?) I think IBM LCS on the mid-scale 360s were rectangular. I assume by rectangular you mean that all wires were on a rectangular grid, parallel to the select wires. The google article on core memory shows a CDC 6600 core plane that shows no sign of diagonal wires. I think many old core planes with big cores ran all wires on a square grid, as there was plenty of window area in the cores. When they went to smaller cores and combining the sense/inhibit winding, then the diagonal wire threaded more easily through the remaining window after the X and Y select wires were in place. Jon
Re: Stuffing boards with pulled QFP chips
On 04/02/2017 07:26 AM, David Griffith via cctech wrote: That's why I put this in the context of PNP robots rather than hand-soldering. My last run of P112 boards was 150 and I'm thinking of doing another 150 or maybe 200. Phew, I sure wouldn't want to hand solder 150 - 200 boards! Been there, done that, never want to do it again! There are machines that can do reasonable lead pitch spacing without vision, using mechanical alignment. My Philips CSM84 does 0.65mm lead pitch TQFPs quite well. One other detail is lead coplanarity. The leads from the manufacturer are formed AFTER plating to all sit on a flat surface. If the leads have varying solder thickness after removal, or are bent out of the seating plane by handling, that will also affect the ability to reflow solder them reliably. Jon
Re: Stuffing boards with pulled QFP chips
On 03/31/2017 11:15 PM, Chuck Guzis via cctech wrote: I use pretty much the same method, but start off with just a binocular loupe and then finish with a stereo microscope for final inspection. Oh, the trick for this is there are inspection microscopes with long working distance that allow you plenty of room to get your hands and tools under them. Generally from about 4-6". Then, it is a breeze to solder under the microscope. Jon
Re: Stuffing boards with pulled QFP chips
On 03/31/2017 12:55 PM, Jim Brain via cctech wrote: On 3/31/2017 12:51 PM, allison via cctech wrote: Is this something that an experienced hand can manually do? I can verify that it is indeed possible. I lay down xc95144xl-tq100s all the time with my iron and some flux and some wick, and I get nearly 100% rates. My eyes are not what they used to be either, so a magnifying glass and a light touch makes all the difference. I am sure others on list are even better than I, but I recommend flux, place the IC, and then carefully set the board aside to dry. The flux will dry, turn into "glue" (as the alcohol evaporates), and that helps with soldering. For chips of the 0.65 mm lead pitch, you should be able to lay a bead of solder paste down with a syringe, and then tack down 2 corner leads. Once that is done, you can draw the soldering tip across the leads and solder one whole side in about 10 seconds. A big solder short will just roll down from lead to lead until it is at the end. You need the soldering tip to be pretty hot to draw the solder along with it. It does take some skill to know just how much solder paste to put down -- you want very LITTLE paste for the draw the blob along trick to work. Jon
Re: Stuffing boards with pulled QFP chips
On 03/31/2017 06:28 PM, allison via cctech wrote: Is this something that an experienced hand can manually do? Yes, definitely. 100 lead PQFP is perfectly doable if the lead pitch is not insanely small. It takes a good fine tip soldering iron (mine is a Weller with a PTS tip), fine solder (preferably real, i.e., 63/37 non-PC solder). Liquid flux is a big help, as is a magnifier and bright light or modest magnification microscope. If you have to do a couple of dozen boards this gets very tedious, but for 5-ish it isn't a big deal. I have a project I do from time to time using 128-lead 14mm TQFPs with 0.4mm lead spacing. I use a stereo zoom microscope with a home-made LED ring light. First, I rub the pads with a pencil eraser to remove oxidation caused by reflow temps on the rest of the board. I put a tiny dab of solder on two pads at opposite corners. I then place the chip in place and reflow those pads. If the alignment is not good enough, I can "walk" the chip a bit by reflowing one, then the other pad. Then, I apply liquid flux to the rows of leads with a wire dipped in the flux. And, then solder down the rows with a fine-tip soldering iron. If a bridge develops, solder wick fixes it. Jon
