At 03:16 AM 3/8/2021, Tor Arntsen via cctalk wrote:
>Linux distros come with a standard tool to do some of that,
>'testdisk'. From the overview:
I'm familiar with the various undelete tools for Windows and Linux.
Such tools may not exist or make sense for older file systems.
Entire files would be great to find, but I suspect interesting
fragments may be more likely.
Running a Windows-based tool like Recuva on a hard drive leads
to such a firehose of fragments if you choose the deep scan that
examines all unused blocks. I've only tried the free version.
Does the pro version give you a way to exclude all the dozens
of OS file types that are probably not the user-made files
that you want?
And for the archaic disk formats, it would be good to have
platform-specific methods of identifying fragments to guess
their file type beyond executable and ASCII. Older run-length
compression image formats may be more possible to recover than
today's block-compressed images.
- John
I was just asked some questions about how RSTS identifies your processor type. Since that topic might be of broader interest I figured I'd do some code reading and summarize the logic.
In the RSTS initialization code (INIT.SYS), the first step is to identify what your hardware looks like. That is a combination of CPU type, bus type, memory layout, and peripheral configuration lookup. They aren't strictly separated into sequential blocks for those four activities, though naturally you'd want to know the bus type before you start looking for I/O devices on that bus.
What I describe here is in RSTS/E V10.1. The general idea of scanning the hardware was introduced in V6B, and I believe is basically the same from that time onward apart from the addition of support for more hardware types. Prior to V6B, the assumption was that you had the hardware you specified during SYSGEN, neither more nor less.
Here is an outline (not all the details) of the hardware scan flow:
1. If word 0 of the boot block contains a zero, this is a Pro (CT bus); otherwise it isn't.
2. Make sure the MMU exist; if not, halt.
3. Check the CPU type (MFPT instruction). If it's an F-11, see if 177570 exist. If yes, 11/24 (Unibus); if no, 11/23 (Qbus). If it's a J-11, read the board type register at 177750 and use the bus type bit to distinguish Qbus from Unibus.
4. Check that there is a clock, and if possible determine the power line frequency.
5. Check if there is a CPU cache, and whether there is a cache error address register.
6. If Qbus, check whether there is memory above the 18 bit range.
7. Check that there is at least 96kW of memory (but the message says that 124kW is required -- the actual check value was apparently overlooked and not updated).
8. Check CPU features: EIS (required), FPP, FIS, switch register, display register, MED, two register sets, system ID register, CIS, Data space.
9. If Unibus, check for UMR.
10. Find where memory is. This is done by looking at every 1kW address to see if it answers. So unlike some other operating systems, RSTS will keep looking if it finds a hole in memory. The kernel needs to be at 0 and contiguous, but holes above that are not a problem.
11. Scan the I/O bus for peripherals. This uses the fixed addresses and float rules for Unibus/Qbus (either, the code doesn't care) or the slot use bits and device type register codes for the Pro.
12. Find the vectors, which for almost every device is done by making it interrupt.
13. Identify specific device models if we care, like RL01 vs. RL02, Massbus disk type, DMC/DMR/DMP, etc.
14. Find which of these devices we were booted from.
That's about it. Once you get past that point the INIT prompt appears and you can ask what INIT found with "HARDWARE LIST".
Incidentally, RSTS doesn't try to identify the exact CPU type you have. Instead, it cares about features or distinctions that affect the code. In a number of cases it does report the type -- if MFPT works then "hardware list" will report that information. But for older CPUs, it doesn't say explicitly, though you can deduce it to some extent. If no type is given but there is cache and more than 128 kW of memory, it's an 11/70. If MED is available, it's an 11/60. If it has FIS, it can only be an 11/40. Etc...
paul
? Saw this on EBAY today - three RK05s with what looks like at least
part of RSX11D on them. Who knows, it might be a distribution - RSX11D
distributions came on 3 RK05s.
https://www.ebay.com/itm/PDP-11-RSX-11D-Executive-Programs-Phase-II-3xRK05-…
? The auction starts at? more than I have in my computer budget this
month, though - would some other RSX historians like to go in together
on this (preferably at least one person with an RK05 drive)?
? I'd just like the contents of the disks - I don't care about the
physical disks, just what's on 'em
--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason at comcast.net
Hi there,
I am working on a 30 minute historical video about the digital group. For source material there isn't a ton of stuff out there unfortunately and much of the account of what happened to the company comes from the late Dr. Robert Suding. In his account, Suding sort of points fingers at Richard "Dick" Bemis for mismanagement of the company.
I am wondering if anyone knows what became of Mr. Bemis after his stint running dg. Apart from a couple of (slightly snarky) letters to Dr. Dobb's Journal when dg was still operational, there's literally no trace of him on the internet. If he's still around I'd love to get his side of the story to balance things out, or at least find out what he did afterwards.
Thought I'd write here in case anyone knew.
Brad
Looking for suggestions on hobbyist PIC setup. So far I have just used
Arduino type direct-connect microcontrollers (back in the day
programmers for general devices were expensive), but the currently
existing SGI proprietary system to PS/2 keyboard adapter is PIC (and I
have a couple different systems that all use my single SGI proprietary
keyboard).
Any gotchas with the PICKit-3 clones out there? I have the feeling that
sticking with PIC would be better than trying to port to Arduino, and
imagine that as things continue to age there will be more applications
for interfaces. Any better but still cheapish alternatives for
programming?
I'm having trouble using DECtapes with TSS/8 under SIMH. I tried with both the
RF image and LCM RK05 image and no mater what I do it hangs if I try to
access a DECtape.
I am trying to use COPY command from account 2.
I attach a dectape in simh then assign it in TSS and then try to get a
directory or zero the tape with copy. Both hang. Anybody with more TSS
knowledge know how to get this to work.
Images from bitsavers http://www.pdp8online.com/ftp/images/bitsavers/unknown/
7196, 7211, 7242, and 7280 have text where TSS/8 was mentioned. These are the
ones I wanted to use TSS to see if I can get a directory.
7241, 7253, 7264, 7265, 7275, 7278, 7291, 7292 have contents but nothing I
can identify.
There are also some LINCtapes that had read issues so unable to determine
what the are.
What I have decoded
http://www.pdp8online.com/images/index.shtml
See last 3.
I am posting, with permission from Daniel, the following "For Sale" message from the HPLX Mailing List for a large collection of HP LX Palmtop hardware, software and books. Daniel Hertrich has been a major contributor to the HPLX List, creating a backlight mod, and doing HPLX repairs. His web site, www.hermocom.com, has been an important repository of information about the HP Palmtops. He can be reached at daniel at hertrich.photo and is located in Bavaria, Germany. I have no interest in the sale, etc.
Regards, Bob
<Begin Forwarded Message>
Hi friends :)
In short (longer text below):
You can see my collection in detail here:
https://360bayern.de/pano/daniels_palmtop_collection/index.html
(zoom in with zoom gesture or scroll wheel)
2,000 ? total for the entire collection. Shipping or delivery from Bavaria, Germany.
You can hover over each item and get a description tooltip (except for items that are self-explanatory, such as the books), some are even clickable, and the click leads to a website describing the item. Most clicks lead you to my own website www.hermocom.com, because I documented a lot of the stuff that I worked on back then. :) If you like to provide more link targets for the items, please do so. then I'll gladly add them.
Note that for the high-resolution image (300 Megapixel) I used panorama software to stitch 10 individual images, so you can zoom in and see a lot of details of the single items. But given the unusual "panorama" setup for capturing the collection, there are stitching errors in the image, so some items look as if they might be broken, but they are not. ;) You can always switch to the lower-resolution standard image (40 Megapixel) to check that there is really no crack in the item. The descriptions and (obviously) the high details when zooming, however, are only available in the high-resolution image.
So here comes the longer text: :)
No, I won't say goodbye to you! I'll stay here with you. And I'll keep a few items from my collection for myself. But the rest of my collection has to go. The Palmtop hobby was a really great one for me, probably the most important one, until I began with photography. I learned so much during all these years since 1997, when I bought my first 200LX. Until 2005 the 200LX even was my main computer (i.e.: the one I used most). I started so many hardware and software projects to support my own work and also the community, and I got a lot of support from you, the community, as well. Thank you so much for that, and for all these years of fun! :) I have (even until now!) never been part of a community that I gave to and got from that much support and heart-warming talks, even if the topic was most of the times a very unemotional one: Computers!
I've even built my own small business around all that ("hermocom - hertrich mobile computing"). The business was never really "successful" in the sense of earning money, but that was not important to me. Important was, that I could take the money earned from it and invest it into new research, new projects, new hardware, to keep it all going and constantly improve.
I think, the most important success (again, not in the monetary sense) was the development of a feasible and relatively affordable backlight solution for the 200LX, made possible by the great help of Hal Goldstein and his team at Thaddeus Computing by handing me over their material they got from their own research in this field.
I will keep two used 200LXs and one 1000CX, as well as a few important accessories (an LED light, one 200LX has a backlight, some PCMCIA cards etc.) and spare parts, but all the remaining parts and devices, even two like-new(!) 200LXs just take up space here and only once a year or so they give me nostalgic feelings and a smile.
Given that I am currently in a financial emergency situation with my photography business, that's heavily damaged due to the Corona situation, I clearly need the money more than the nostalgic feelings. :)
For each item in the collection (except for almost all the books and a few trivial items, which I will add for free), I estimated a value, then summed up these values and resulted in a total value of 2,300 ?.
I would prefer to sell the collection in its entirety, and would offer the entire collection for 2,000 ?.
That price does not include shipping costs.
In case nobody wants to buy the entire collection for a couple of weeks, I'll probably slice the collection into smaller chunks or offer items one by one.
If you are interested in a particular set of items (collection chunk), let me know. I may consider that.
The collection fits into a standard-sized moving box, with not much padding. For shipping, I'd like to add much more padding, so that it would probably take 2 moving boxes for shipping.
Within Germany, I would deliver the collection in my area for free (85077 Manching, near Ingolstadt + 100km). I'd also consider delivering it within a wider distance against a refund of my driving costs. That would maybe be cheaper than parcel shipping for two heavy moving boxes and it would allow for a beer and a good talk :)
Okay, so now have fun exploring my collection. :)
If you are interested or have questions, you may contact me at daniel at hertrich.photo.
....This is quite an emotional step for me... Oh boy.
Daniel
> From: Paul Koning
> Here is an outline (not all the details) of the hardware scan flow:
> ...
> 2. Make sure the MMU exist; if not, halt.
> ...
> If it has FIS, it can only be an 11/40.
You probably know this already, but the KEV1-A floating point chip for
the LSI-11 also implemenred FIS. (Of course, the LSI-11 would fail
step 2, so it's not really a factor here.)
Noel
