Question: I just used a strong magnet to wipe an old Maxtor MFM drive
(magnet on outside of case). Now the drive will not even seek properly
on start up, just endlessly moves the heads..
Is the drive now toast? Do MFM drives have embedded servo information on
the platter formatted by the factory?
CZ
For my LSI-11 simulator I developed an as accurate as possible
implementation of the Console-ODT functionality as described in the "LSI11
PDP11/03 Processor Handbook" and the "Microcomputer and Memories Handbook".
As might be expected from these handbooks, the description of the ODT
functionality is not a complete specification and consequently during the
development several questions arose on the reaction of ODT on the user
input, such as:
- What is the reaction on commands like "R0/<CR>RS/4@"? Will the last opened
location be opened or the contents of the last opened location?
- What is the reaction on a RUBOUT at the prompt?
- What will be the value of the opened location when e.g. three digits are
entered and these three digits are then rubbed out and the location is
closed? Will the value of the last opened location be unchanged or will it
be zero?
- An address and a GO command can be separated by a semicolon. What is the
reaction if characters other than the "G" are typed after the semicolon?
- Etc., etc...
Is there someone in (the vicinity of) the Netherlands with a functioning
LSI-11 who would allow me to try out these commands or could anyone point me
to someone who could facilitate that?
I developed a complete test script for all LSI-11 ODT commands and "all"
relevant situations and ideally I would like to carry out this test script
to get a complete specification of the Console-ODT functionality.
Regards,
Jos
Hi all,
I picked up the pieces of a few Sun E3500s a while back but it looks like I
don't have enough for a complete system - I am missing the front Peripheral
Power Supply, 300-1358 (
https://dogemicrosystems.ca/pub/Sun/System_Handbook/Sun_syshbk_V4.1/Devices…
). I know there's one on eBay right now but I have extras of most other
parts for these machines - rear power supplies, cooling modules, FC-AL
boards, SBUS boards, etc. and would ideally like to arrange some sort of
mutually beneficial swap. Let me know if you're interested and we can work
something out. Shipping is probably not going to be prohibitively
expensive but if there is someone local I'm in the greater Cleveland, OH
area.
-Henry
G'day all,
I have just uploaded the engineering drawings for the early PDP-11/05, the one with the solid (no slots) Mazak lower bezel
and the M7261 with the unpopulated region.
The latest date I can find in this print set is October 1973, Drawing release 11/05-49.
You can view or download it from https://archive.org/details/pdp-11-05-engineering-drawings-oct-1973
It is 147Mb in size, sorry about that but I didn't want the quality to drop too much (the raw scans were ~350Mb).
Regards,
Steve.
Is it possible to use the MXV11-B2 Roms in an 18 bit MRV11-C Prom
board? Clearly they work in the 22 bit version, MRV11-D, but I don't
have one of those.
The intention is to put together a small PDP-11 in an H9281-AB backplane
(18 bit) with an 11/23 or 11/73 CPU, Ram, disk controller, etc.
> But, as some who worked
> to bring a product to market only to see people on forums say "Skip
> buying it from Jim for $$$$, you can build the same thing by yourself
> for $ from AliExpress parts or buy this eBay knockoff for 2X$", I will
> admit that is somewhat infuriating. If the hobby community is not
> willing to pay a bit of premium to support those who bring out the
> products that benefit the community, the designers will get disgusted
> and leave.
Agree 100%. We stopped running XT-IDEs for a while due to the proliferation of knockoffs and the total indifference of a good portion of the community -- some folks even get hostile when you suggest they maybe not buy knockoffs that can't even abide by the terms of the open-source project license!
I'd designed a universal "bolts to any existing XT-IDE and doesn't eat a slot" CF adapter that never got run. After posting a development picture of the prototype, one of the knockoff folks ripped the design off before I had even received my quote from Keystone for the custom ISA brackets. No way was I going to spend on a run of 500x custom brackets when someone was already ripping off the idea. There are other things that we've chosen not to run for the same basic reason, and others that won't get open sourced.
> Thus, I'd say if a Saleae is something to pursue, try to buy
> one from them, to support their awesome GUI, and then drop by eBay and
> grab 2 or 4 of the knockoffs to put in your toolbox or travel debugging
> rucksack.
I'll go further and say don't buy knockoffs, period.
It's nice to support the designers in some capacity, but buying knockoffs fuels the ecosystem that creates knockoffs. With our stuff, it's never been that a single knockoff operation eats our lunch, it's that there's a zillion of them that run maybe 100 boards and disappear. Death by a thousand cuts. They charge $1-5 less while running the cheapest possible boards, stuffing with salvaged chips, etc. Meanwhile, we're having to pay for runs of boards with hard gold plating and buy genuine parts from Mouser.
Thanks,
Jonathan
The mandatory update for VMS V4.2 is still missing in my collection.
Because of that, VMS V4.2 is not fully usable,
neither can layered software be installed nor can
it be upgraded to VMS V4.3.
Who can help???
Not to open a huge can of worms.... but...
I always considered a mainframe to basically be a "fully decked out"
minicomputer.
A minicomputer has a core CPU and memory (or racks of memory), then is
"decked out" with data storage (racks of wall-sized tape decks), printers,
pick-your-typewriter input (or two, or three), and maybe cabinets for
serial IO or modem of some sort.
So, sometimes I say mainframe when I really mean minicomputer (generally
because mainframe just sounds cooler than "mini-computer" -- that is,
mainframe clearly conveys the notion of "some big ass computer" whereas
minicomputer just needs more clarification).
What do you guys think? Or is a mainframe one of those giants so large,
you walk inside its CPU?
Or, is it like this...
computer (a whole building, generally at least two story to support ac
ducting and raised floor maintenance -- are these exclusively mainframes?)
minicomputer (a single floor or room of a building or possibly a full
top of a desk - and, these are NOT mainframes?)
microcomputer (half a deck top or smaller, memory and accessories mostly
self contained - doesn't necessarily have to have a microprocessor, but
typically does)
nanocomputer (modern MCU ? like Raspbery Pi)
Also - on "personal computer", it's generally implied "digital electronic
computers" so we don't have to dwell too much on rocks and beads as
computers. Glad we didn't call them "coordinated electron pumpers" :)
-Steve
Ok, I think we have a good narrated composition! It is still
Unlisted since there are a few more things to finalize/decide. But unless
we spot any major flaw in the rendering, this should be wrapped up over the
next day or so. There are a few somewhat subtle easter eggs added.
https://www.youtube.com/watch?v=HPrHfUrhjQk
<Domesticating the computer: how the appliance computer came to be - YouTube
<https://www.youtube.com/watch?v=HPrHfUrhjQk>>
One question is: should this be set to "Yes it is for kids"? My
understanding is Enabling that prevents Comments being enabled, but I'm not
sure if there is any other benefit. But yes, this is NOT a documentary
and is intended more for a middle/high school audience.
Other decisions are things like final thumbnail and writing up the
Description, credits, etc.
And - recall - this wasn't intended as a "full history of computing", the
focus was on the 1970s. But there is a brief segment towards the end that
honors some pre-1970s work.
Also, this may be the only "history of personal computer" related video
that doesn't mention the word Gates or Wozniak [ that wasn't exactly
intentional! ;) actually the original intent was to avoid any names at all,
it wasn't a biography - but a few do end up mentioned ]
Thanks for all the feedback and criticism - it won't be perfect for
everyone, but I think it is far better than what we started with. My
"technical review team" has included:
Dennis Roberson (SCAMP/IBM 5100 lead engineer)
Dan Bricklin (VisiCalc)
Scott Adams (Adventure and many other games)
Ken Williams (Sierra OnLine)
-Steve
Any interest here before I post them to EPay?
Available for shipping cost from 95549:
IBM RT PC AIX OS Communications Guide 59X7668
IBM RT PC AIX OS Messages Reference 59X9115
IBM RT PC INED 59X7643
These are the classic early slipcase style manuals. They are in
pristine condition. All three are 1985 "First Editions" of the pub.
I received them in an auction lot of of documents and have no need.
Combined weight is ~13lbs.
Steve
