Re: idea for a universal disk interface
shad said > Hello, > I'm a decent collector of big iron, aka mini computers, mainly DEC and DG. > I'm often facing common problems with storage devices, magnetic discs and > tapes are a little prone to give headaches after years, and replacement > drives/media in case of a severe failure are unobtainable. > In some cases, the ability to make a dump of the media, also without a > running computer is very important. > > Whence the idea: realize an universal device, with several input/output > interfaces, which could be used both as storage emulator, to run a computer > without real storage, and as controller emulator, to read/write a media > without a running computer. > To reduce costs as much as possible, and to allow the better compatibility, > the main board shall host enough electrical interfaces to support a large > number of disc standard interfaces, ideally by exchanging only a personality > adapter for each specific interface, i.e. connectors and few components.> > There are several orders of problems: > - electrical signals, number and type (most disk employ 5V TTL or 3.3V TTL, > some interfaces use differential mode for some faster signals?) > - logical implementation: several electrical signals are used for a specific > interface. These must be handled with correct timings > - software implementation: the universal device shall be able to switch > between interface modes and be controlled by a remote PC > > I suppose the only way to obtain this is to employ an FPGA for logic > implementation of the interface, and a microprocessor running Linux to handle > software management, data interchange to external (via Ethernet). This means > a Xilinx Zynq module for instance. > I know there are several ready devices based on cheaper microcontrollers, but > I'm sure these can't support fast and tight timing required by hard disk > interfaces (SMD-E runs at 24MHz). > > The main board should include a large enough array of bidirectional > transceivers, possibly with variable voltage, to support as much interfaces > as possible, namely at least Shugart floppy, ST506 MFM/RLL, ESDI, SMD, IDE, > SCSI1, DEC DSSI, DEC RX01/02, DG6030, and so on, to give a starting point. > The common factor determining what kind of disc interface can be support on > hardware side is obviously the type of transceiver employed, for instance a > SATA would require a differential serial channel, which could not be > available. > But most old electronic is based on TTL/CMOS 5V logic, so a large variety of > computer generations should be doable. > > For the first phase, I would ask you to contribute with a list of interfaces > which could be interesting to emulate, specially if these are similar to one > from my list. > I please submitters to send me by email or by web link when possible, > detailed documentation about the interface they propose, so I can check if it > could be doable and what kind of electrical signals are needed. > Also detailed information about interfaced I listed is appreciated, as could > give some detail I'm missing. The Diablo / Pertec interface was a popular industry standard. Here's a product (no connection) that implements it https://www.arraid.com/data-storage-products/product/aem-5c.html It would be great if there were open source or cheaper devices, maybe there are, I guess the Unibone can do this? (I don't have one yet) (btw I never actually subscribed to cctech but somehow my cctalk ones get echoed over there)
Re: The precarious state of classic software and hardware preservation
Adam wrote >> On 11/19/21 9:33 PM, Steve Malikoff via cctalk didn't write: >> >> And what happens when you wake up one morning to find archive.org is >> gone, too? >> >> > Fundamentally, eventually we're all going to be indistinguishable > mass-components inside the supermassive black hole that used to be the > Milky Way and Andromeda galaxies anyway. > > Smoke 'em while you got 'em. I did not write that line, it's misappropriated from a followup. But I agree with the sentiment that entropy is going to win in the long run. That scene in 'Bill and Ted's Excellent Adventure' where Socrates pours dust through his fingers kind of sums it up :) Steve
Re: Looking for info on memory
> On 10/19/2021 12:57 PM, Nigel Johnson Ham via cctech wrote: >> I am trying to bring up an 11/23 system in a BA23 box, and the only >> memory i have is an obscure Plessey one. The only identification is the >> p/n 705920 with dash-100 in white ink. By counting the chips I make it >> 4MB, but it does not respond. Since it takes the full 22-bit memory >> space I can't see how any jumpers would change its accessibility. Does >> anybody have a manual? FoothillsGeek on VCFed had a number of Plessey memory manuals and had scanned some, as mentioned here https://www.vcfed.org/forum/forum/genres/dec/73251-dec-documents-on-manx
Re: Looking for video (or photos) depicting how to remove ASR 33 printer from keyboard
Bill said > I am looking for a video or photos that show how one removes the printer > from the keyboard safely on an ASR 33. I need to get to the underside of > the printer levers so I can re-align them. I am getting incorrect > characters when I type over half of the keys. I can see that a few levers > are out of whack or not seated correctly but I believe to get to them > properly I need to put the printer on its side or under a lift to get to > the underside. I am nervous about detaching the "H" shaped gizmo that > connects the keyboard to the printer. This video, Part 2 of a series by Jerry Walker seems to cover removing the keyboard from the printer pretty thoroughly, including how to take out the H piece: https://www.youtube.com/watch?v=w6VoPIp_wd4 Also I think Marc's videos cover it too. Steve.
Re: PDF of FANUC TAPE READER A860-0056-T020 Manual Wtd.
> Here is the Ebay auction, I hope the manual is included assuming the 50-pin > port is the output port. > > https://www.ebay.com/itm/GUARANTEED-GOOD-USED-FANUC-TAPE-READER-A860-0056-T020/392104833775?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 Perhaps try the IndustryArena CNC forum at https://www.cnczone.com/ they have some FANUC postings there at the moment. Steve.
Re: Wanted, Papertape Reader for Archiving Tapes
Bill said > 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, or recommend one currently out there on Ebay, I have an EECO MT-82 (manual on bitsavers), and it's ok but pulls the tape through in short sharp bursts rather than a continuous smooth action, even on the lowest baud rate. I have the serial version, there is a separate I/O board for serial and parallel. For some reason the right-hand spindle always runs, perhaps the driver transistor logic has some problem. I don't use the spindles anyway as I have no reels (I am designing 3D printed ones) but the spindle speed is way too fast for old tapes anyway, I think. With the OP-80A you could try rigging up a small motor to pull the tapes through at slow speed, say a LEGO Technic M size motor driving LEGO tires through a simple gearbox. And build up some sort of tape guide from LEGO as well. Steve.
Re: VT52 stand
Marc said > Does anyone on the list have or have seen the stand that DEC sold with the > VT52? I'm just curious; does the stand screw into holes on the monitor or > does it just sit on top? > > From what I've seen before it just looks like an office chair base with a > top that is the correct size. > > Thanks, > > Marc >From the DEC Sales Catalog Fall 1978 http://www.surfacezero.com/g503/data/500/DEC_VT52_stand.jpg Steve.
Re: "Plug and Play" adapter for PDP-11/70 panel - BlinkenBone update
That's really nice! Looking at your photos there seems to be an ability to re-jumper the console ribbon cable on your new board, if so would it be able to be then used with other original PDP-11 consoles? I am doing up the CAD model for the 11/05 console (it's really quite a simple shape) and its switch register board so anyone could print it off and have an accurate full-scale replica (C&K switch paddles done already). Steve. Original Message Subject: "Plug and Play" adapter for PDP-11/70 panel - BlinkenBone update From:Jörg Hoppe via cctech Date:Wed, January 16, 2019 8:17 pm To: "General Discussion: On-Topic Posts" -- > There's a new adapter board for the BlinkenBone system. > Now you can painlessly plug a physical 11/70 panel to the extended SimH > running on a BeagleBone. > > See > http://www.retrocmp.com/projects/blinkenbone/physical-pdp-11-70-panels/288-pdp-11-70-console-panel-on-blinkenbone-plug-and-play-adapter > > Entry to far-too-many web pages here: > http://retrocmp.com/projects/blinkenbone > > All in all there are now at least 3 different (but compatible) ways to > get a blinking 11/70 with SimH. > > - Connect a real 11/70 panel > http://retrocmp.com/projects/blinkenbone/physical-pdp-11-70-panels > > - Run the virtual Java panel > http://retrocmp.com/projects/blinkenbone/simulated-panels/243-blinkenbone-panelsim-pdp11-70 > Download &run from github https://github.com/j-hoppe/BlinkenBone/releases > > - get Oscars Vermeulens PiDP11 > http://obsolescence.wixsite.com/obsolescence/pidp-11 > > Is that enough '70 now? > > > Joerg > >
RE: Original CAD code in the wild?
I don't know if any source is still available, but for a long time I've been fascinated by Ivan Sutherland's Sketchpad running on the TX-2: https://www.youtube.com/watch?v=USyoT_Ha_bA Since Sutherland's technical report is also on the web (https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-574.html) I reckon it would make for a great 3rd-year Computer Science graphics assignment, to replicate Sketchpad using a high level language. A look through the report shows the use of rings, linked lists, recursion, storage considerations, maths, graphics and so on (only needing to replace the light pen with the mouse of course) which could be a fascinating exercise for a student. Yes there are already Sketchpad-named apps and Sketchpad-like programs, but I'm not sure if there is a near-100% faithful recreation of that original program as demoed in the film out there. Steve.
Re: who is in this picture? (VCF 199x)
Bill said > https://retropopplanet.files.wordpress.com/2011/06/vintage-computer.jpg > > I was not at this particular VCF out in California in the later 90's when > this photo of a DEC exhibit was taken; the original picture from vintage.org > is no longer hosted. > > Does anyone have a copy of the old vintage.org exhibit/photo archive? > > Bill >From the LSX Unix Restoration Page: http://www.mailcom.com/lsx/ Steve.
Re: Replacing flat drive belts alternatives?
Craig said > I would like to have both the drives in my HP 9895A working. Since flat belts > for old equipment are becoming nearly impossible to find, has anyone had > success replacing a flat belt with a toothed? Either by reversing the belt > or by also replacing the pulleys? Or by the installation of an idler pully to correct for belt stretch? Have you tried a mechanical parts supplier such as Stock Drive Products? for instance Metric range of flat belts http://www.sdp-si.com/PDFS/Flat-Belts-and-Pulleys-Metric.pdf Imperial range of flat belts http://www.sdp-si.com/PDFS/Flat-Belts-and-Pulleys-Inch.pdf McMaster-Carr if you are in the US https://www.mcmaster.com/#flat-drive-belts/=18mscic >From a quick search there are also various sizes of flat belts on eBay, for >audiophiles restoring old tape decks. Steve.
