test-drb November 2019

test-drb@ccmp.vtda.org

147 participants
137 discussions

by jnc＠mercury.lcs.mit.edu

> From: Richard Pope > Isn't the proper term for my network of computers here at home: > internet It depends on what's inside it. An 'internet' is a collection of disparate networks tied together with packet switches which examine the internet-layer headers of the packets passing through them (such boxes are now known as 'routers'). The "internet layer" doesn't appear in the ISO 7-layer model, since the concept didn't appear until after that was done; but you can imagine it as layer '3A', crammed in between 3 ('Network') and 4 ('Transport'). Note that there are a number of networking protocol families that include the internet concept; CHAOS, PUP, XNS and DECnet among them (although there are several versions of DECnet and I no longer remember the details of most of them, so take that one with the proverbial grain, but several had internets). Does does the network in your house use router(s) to tie it together? If so, it's an internet; if not, no. If you have a wireless hub, connected to a CATV modem, you probably have a small piece of 'the Internet' in your house. (See below.) Note that there are still internets (and networks) which are not connected to the Internet - Google for "air gap". > and the term : Internet the proper term for the worldwide collection of > networked computers? Originally 'the Internet' was the large TCP/IP internet centered around the ARPANET, and later the NSFNET. These days, the concept is more diffuse - there was some discussion recently on the internet-history list: http://mailman.postel.org/pipermail/internet-history/ about it, but I'm too lazy to track down the exact messages. Noel

5 years, 1 month

TurboDOS for S-100, IMS or L/F Technologies

by new_castle_j＠yahoo.com

Yes, I was able to determine that the TurboDOS 1.41c disks which would complete my particular setup do exist and that they are in good hands, however I have not been able to get copies of the disks as of yet. I'm hoping that patience will prevail and perhaps another copy will turn up or the copies that I know about might someday become available. The 16-bit 1.43 version that you need is readily available as 5.25" disk images. I've got copies of them and they work well. If you need it on 8" floppy, I can probably convert them using my IMS system to write them to 8". Getting a system up and running is not that difficult, I can guide you through if there's any trouble. Jonathan __________________________________________________________________________________________________ did anything more ever turn up? I'd like to try getting a 16-bit 1.43 running, there is a set of disks on ebay, but the seller has blocked me https://www.ebay.com/itm/193098921854 On 6/28/19 7:17 PM, Jonathan Haddox via cctalk wrote: > Just sending a thanks for the replies from various folks on this list. I was able to recover a partial set of operating system files for my IMS/LF-Technologies S-100 machine from members who dug deep into their archives. It's booting now to a basic single-user TurboDOS 1.4 which proves that my hardware is sound. In order to get what I really want out of this machine, I still need to source a full set of TurboDOS 1.4 drivers (.REL files) from IMS L/F Tech distribution diskettes. I'll be around if they ever turn up. > > Thank You! > > IMS A645 Z-80 Processor > IMS A631 serial/parallel I/O > IMS A930 Floppy controller > IMS A465 64K RAM > IMS 1100 Winchester Hard disk controller > IMS 862 User Processor (Z80) > IMS 1081 User Processor (186) > IMS 1120 Tape Controller On Tuesday, June 11, 2019, 11:55:29 AM CDT, Jonathan Haddox <new_castle_j at yahoo.com> wrote: > > I'm restoring an IMS - L/F Technologies S-100 Bus computer.? I've got all the pieces except for the Operating System.? I'm hoping that someone here may have a disk stashed away.? From the literature I have read, I would need TurboDOS version 1.40a or 1.41c from IMS or L/F Technologies.? I've seen TurboDOS 1.3 versions out in the wild from IMS, but the 1.4 version was greatly enhanced and offered better compatibility with my specific hardware.? I'd be much obliged if anyone can help. > > Thanks, > > Jonathan > new_castle_j? at yahoo

5 years, 1 month

DEC KA650 VAX memory troubleshooting (video)

by joezatarski＠gmail.com

Hey Everyone, I just thought I'd share a video of how I'm going about troubleshooting the bad DRAMs on my MS650 memory board. https://youtu.be/eDMhdAEFEgc I apologize for the shaky-cam, I don't have a tripod, and I needed to do a lot of panning anyway. I will be sharing my notes on the MS650 once I have a chance to write them up properly as well. I wasn't able to find a printset for the RAM card itself, so I assume one doesn't exist in digital form yet. I have documented what bit and memory range each DRAM on the card corresponds to, which may help someone troubleshooting in the future Regards, Joe Zatarski

5 years, 1 month

Who changed the gravitational constant (Dec pdp11 stuff)

by jnc＠mercury.lcs.mit.edu

> From: Chris Zach > The MSV11-QC board ... failed startup diagnostics with what looks like > a stuck bit. .. now I need engineering schematics for that board so I > can replace one of the 41256 memory chips. On the positive side it looks like > a pretty obvious stuck bit, just need to know which chip is at that > address and memory location.... I suspect you're out of luck on the prints, I think all there is is the User Manual. Not to worry, it should be pretty easy to create a bit->chip table, I did that for the MSV11-J: https://gunkies.org/wiki/MSV11-J_QBUS_memory#Technical_information when I needed to repair one; it should be pretty easy to duplicate the process for the -Q. I did it with a 2-instruction scope loop, doing a word write to a given location, floating a '1' bit along a word of '0's, looking at the 'data in' pin on the DRAM chips. I see the -Q has a 17x8 array of DRAMs, so 16 bits of data and a parity bit (odd chip out); so in some ways even easier than the -J (which had ECC). 8 banks, but with a little luck they're in some sort of logical order. I have a -QA, of the later etch rev, which is the same etch as your -QC; so I can help with the mapping process, if you need it; let me know. Noel

5 years, 1 month

UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

by jnc＠mercury.lcs.mit.edu

> From: Rob Doyle > http://www.bitsavers.org/pdf/dec/unibus/RH11-C_Engineering_Drawings.pdf Oooh, thanks ever so much. Not sure how I missed that when I looked on BitSavers for RH11 stuff! Very illuminating - eventually! The M7294-YA seems to be a manual ECO to the M7294; there's a detailed rework list on page 6 of the PDF. I'm still trying to work out what the changes do. E66 is a 'component carrier' header, so it seems like in part the ECO adds a bunch of option-controlling jumpers there (see pg. 2 for a table of what they do). The main thing, though, seems to be the addition of E22, a 74191 binary up/down counter, on page DBCA (pg 10 of the PDF). It seems to modify the operation of 'Bus Hog' mode - maybe to do 16-cycle bursts? (All the bit inputs and outputs are unused; only the Max/Min output - pin 12 - is connected to anything.) That would make sense; with UNIBUS A and B tied together, the original Bus Hog (below) would lock out the CPU from the RH11 until the end of the transfer. Actually, though, even without the cross-connect, having the RH11 going flat out Bus Hog might lock out the CPU from the _KS10 memory_... > However there is plenty of DEC documentation that mentions that the > RH11C has a "bus hog" mode for the KS10 disks so that the Unibus can do > back-to-back 18-bit transactions. The RH11-AB has Bus Hog too; see Section 4.12.10, "BUS HOG Mode", pg. 4-22 (59 of the PDF) in "RH11-AB Option Description" for details; it "hold[s] the Unibus ... until the required number of words have been transferred". Noel

5 years, 1 month

UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

by jnc＠mercury.lcs.mit.edu

> From: Rob Doyle > Your memory is correct. The RH11C was the buffered version of the RH11 Umm, both the -AB and -B have FIFOs - confirmed from the prints. (I have an M7294 if we want to confirm that the prints aren't confused.) Now, maybe the -C has a _bigger_ FIFO (e.g. large enough to hold a complete sector), I could definitely see that. What's your source - I'd like to study/cite it? The only KS10 prints I can find don't show the RP11-C? Noel

5 years, 1 month

UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

by j_hoppe＠t-online.de

>>>> *What it is:* >>>> In case you forgot: UniBone is a plugin board to DEC PDP-11 UNIBUS >>>> systems containing a BeagleBone Black. >>>> >>>> See http://retrocmp.com/projects/unibone. > > Is it possible to get it as a "kit+" where the SMD components only are already soldered onto > the bare board, but all the rest left for those who are ok with a normal soldering iron but > not confident on doing the SMD? Yes, can do that. Joerg

5 years, 1 month

UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

by jnc＠mercury.lcs.mit.edu

> Although, with the 3 SPC slots - although they are on UNIBUS A, and only > UNIBUS B has the 18-bit capability Duhhhh. My brain finally turned on. It is of course perfectly possible to run UNIBUS _A_ (where the SPC slots are) in 18-bit mode too - although the _RH11_ can't use it that way. But you won't be using the RH11 anyway, so who cares? Also, I took another look at the KS10 tech manual, and they do in fact use use an M9200 'thin' jumper (although it's mis-labelled "M9300" in the diagram - that diagram has a number of errors, including the "M8014" in the UNIBUS 'A' In slot - they must mean an M9014 [UNIBUS to 3 flat cables] instead) to link the two UNIBI together. Which answers the question of how the KS10 CPU gained access to UNIBUS A (where the device registers, interrupts, etc are) when it also had to be connected to UNIBUS B (for 18-bit data transfers). So I think all our questions are answerered (except for the -AB/-C difference issue). Noel

5 years, 1 month

TurboDOS for S-100, IMS or L/F Technologies

by new_castle_j＠yahoo.com

I'm restoring an IMS - L/F Technologies S-100 Bus computer.? I've got all the pieces except for the Operating System.? I'm hoping that someone here may have a disk stashed away.? From the literature I have read, I would need TurboDOS version 1.40a or 1.41c from IMS or L/F Technologies.? I've seen TurboDOS 1.3 versions out in the wild from IMS, but the 1.4 version was greatly enhanced and offered better compatibility with my specific hardware.? I'd be much obliged if anyone can help. Thanks, Jonathan new_castle_j at yahoo

5 years, 1 month

UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

by jnc＠mercury.lcs.mit.edu

> the Revision J prints (September 1993). Ooops, typo: '1973'. Noel

5 years, 1 month

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test-drb November 2019