I asked this before a few years ago but didn't come to a firm conclusion. The two parts are shown in this picture: https://rjarratt.wordpress.com/wp-content/uploads/2023/12/img_20231221_1123…
They are from a VT100 Monitor board. There is no schematic for my version of the board, but a related schematic is on p58 of this schematic: https://bitsavers.org/pdf/dec/terminal/vt100/MP00633_VT100_Schematic_Feb82.…. They are labelled Q414 and CR406, but the Feb 82 revision uses a different board and those two parts are in TO-220 packages rather than TO-3 as here..
I have removed both of them and tested them with a DMM. Neither of them measure as two diodes, they do not measure open circuit in any direction, so either they are both faulty or they are not transistors (unlikely). I have found a spec for a 2SB411 at https://alltransistors.com/transistor.php?transistor=10279. This seems to be a germanium transistor. When I last asked about this I had a conversation with Tony Duell, who was very sceptical that these could be germanium transistors, so naturally I am very doubtful that they are 2SB411 transistors. However, in the schematic Q414 is shown as NPN, the 2SB411 is PNP and this seems to match the way the part is connected on my board (Collector to HORIZ GND). I am working on a reverse engineered schematic.
Can anyone tell me what these components are so I can find a datasheet for them? Better still a suggested replacement would be really helpful, especially if they are 2SB411s because they seem to be hard to find.
Thanks
Rob
Nice, Jay! Thank you
> On Feb 22, 2026, at 18:44, Jay Jaeger <cube1(a)charter.net> wrote:
>
> On 2/21/2026 9:27 AM, Jacob Ritorto via cctalk wrote:
>> Hiya.
>> Is DECnet for RT-11 still lost? If not, anyone got a link to it?
>> thx
>> jake
>
> I may have *SOME* of it. I have three RX50's and one RX02 that have some DECNet RT V2.1 files. They are NOT distribution disks, and the disks have hand-written labels, so they might not even contain what the handwritten label indicates - I have not checked them out under SimH.
>
> Anyway, I just put them in my "bitsavers contribution" area of my Google Drive, and they can be found on my Google Drive at:
>
> https://drive.google.com/drive/folders/1fiOScGSpvLiVQ0yyOg2yC5EpqRKiKWQ5?us…
>
> JRJ
Hello,
I'm an employee with the National radio astronomy observatory here in Socorro New Mexico.
As part of our NGVLA upgrades, we are seeking to get rid of old data tapes from the tape reel days of Computing. These contain things such as the boot loaders, OS, specific collection programs and antenna movement programs.
I personally would hate to see these just wind up in the literal dumpster and would like to see them sent out to a museum or an archiving body that can preserve them and keep them safe as a dynamic part of history.
If anyone is interested or knows someone who would be interested in the VLAs data tape library please let me know.
V/R
Danielle Werts
Front end engineer
VLA Socorro New Mexico
I've started working on a disassembly of the Digital VT320 video
terminal, so I'm diving into 8051 assembler.
At the moment, I'm using the D52 disassembler and am getting decent
results, although I wished I hadn't used the analyse option to produce
a starting control file; it doesn't cope at all well with code
involving lots of jump tables because the control flow appears to
break, and it decides that much of the code is just data. Ho hum.
Nevertheless, the code looks pretty understandable at the moment, so
the next stage is to annotate by hand, instead of updating the control
file, and to assemble whenever I make a change so that I can be sure
that I can produce the original ROM.
There isn't an "A52" to match D52, so I was wondering if anyone has
recommendations for a FOSS macro assembler that will take D52's output.
I ask for a macro assembler because there are some modifications I'd
like to make to the source file to clear things up. One of these would
be to cope with the fact that DEC decided that all of their jump tables
would have addresses in little-endian format, despite the 8051 being a
big-endian device. So, the normal "dw" directive is not going to work
for me, and I'll need to do something like:
dwl macro %1
db low(%1), high(%1)
endm
(Totally pulling that syntax out of my bum, btw.)
A quick search finds as31 and naken_asm - anyone use these?
I'd also love to hear recommendations for emulator code for the 8051,
preferably simple C because I'm going to need to hook up a 2681
DUART, 5911 EEPROM and DC7081 video chip (all presumably new code) to
get this working.
Paul.
On 2/21/26 07:48, emanuel stiebler wrote:
> Everex had their own Unix version (5.4?), "ESIX" which ran on intel.
> Probably they ran that?
No, it ran SCO Unix, which was the business version popular at the time.
I found the ad and edition of computerworld in the Internet Archive: The
issue is the June 22nd 1992 one and it has all sorts of interesting
articles and predictions from people like Gates, Jobs, Wang, Bell, and
others. Going to be worth a read here.
Anyway, on the PDF download it starts at page 186-189.
They benchmarked it against a Dec 433MP (could also do 6 processors) and
a SystemPro (2) with 60 user loads. Wow.
A buddy of mine showed off his Wyse 520 and was wondering if anyone on here
has one and if you use it. It's a nice looking keyboard but I'm not that
fond of the small screen.
Daniel
sysop | Air & Wave BBS
finger | calcmandan(a)bbs.erb.pw
Hi,
did anyone ever create an image of the Sun 386i firmware (EP)ROM?
There was a discussion on cctalk two years ago, but it seems the ROM was not dumped back then.
https://marc.info/?l=classiccmp&m=171014099801502
The firmware dump would obviously be very useful to write an emulator for the 386i.
Our department here at Bamberg Uni bought four 386i machines back in 1989 as their first
workstations for a whooping 230k German Marks. It would be nice to be able to show a running
machine or an emulation at our upcoming anniversary (the department itself was only founded
25 years ago, but the 386i machines were purchased more than a decade before that date by
the people who later founded the department), but none of the 386i machines here have survived..
So if someone has a 386i for sale (ideally in Europe, I'm in Germany) I'm also interested...
Best,
Michael
What timing! I’ve been down the 8051 rabbit hole for a few months now.
I cut my professional teeth on Intel assembler back in the mid 80’s so. Never worked with the 8051 (8048/8085/8086/8088 were the processors I used).
What I’ve found so far that may be of use are:
SDCC (Small Device C Compiler). It has an assembler, sdas. I haven’t used it.
I also found the original Intel Macs-51 tools (macro assembler, linker, librarian). I probably prefer the Intel tools because they remind me of the tools I used way back when.
The Intel DOS tools will run on msdos emulators, dosbox-x is one I found useful. It is possible to run dosbox-x without the gui (set up the DOS commands in the autoexec.bat)
dosbox-x -silent -nomenu
The Intel DOS tools are located here:
https://www.retrocomputing.nl/wp-content/uploads/PLM-51/PLM51_V1_2.ziphttps://www.retrocomputing.nl/wp-content/uploads/PLM-51/PLM51_V1_4.zip
Intel documentation can be found with an internet search at a number of sites. The relevant titles are:
MCS-51 MACRO ASSEMBLER USER'S GUIDE
MCS-51 UTILITIES USER’S GUIDE FOR DOS SYSTEMS
EXTERNAL PRODUCT SPECIFICATION FOR THE MCS-51 OBJECT MODULE FORMAT
The msdos emulator is here:
https://github.com/joncampbell123/dosbox-x/releases/tag/dosbox-x-v2026.01.02
I ran into problems building SDCC from the “official” repo. I used the following repo sucessfully:
https://github.com/swegener/sdcc.git
I hope this message arrives in the proper talking group as it is my first
reply within years of reading everything.
If you are getting chastised for using an old computer, just tell everybody
that even the worst modern virus of today does not fit inside the RAM of
your dinosaur, so you are 99.99% protected. Security through obscurity. Ask
your colleagues if they have the same level of protection given only by the
existence of any of their systems, and no other additional software.
I am writing this from an old terminal connected to a FELIX C-256 Romanian
made mainframe from the 1970s. That is a clone of the French IRIS-50 made
by Companie Internationale pour Informatique.
Now that's an ugly beast.
Try to telnet to some modern small system running some BSD / Linux, which
talks to the world, then use BitchX or some other text-based IRC client to
chat.
I am sorry I am in a hurry, big boss at work wants his paperwork done.
Best regards
Vasile Buruiana
Doctor of communist digital dinosaurs
On Mon, Feb 16, 2026 at 8:00 PM <cctalk-request(a)classiccmp.org> wrote:
> Send cctalk mailing list submissions to
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>
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> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of cctalk digest..."
>
> Today's Topics:
>
> 1. Chat program for RSX (Jacob Ritorto)
> 2. Re: Chat program for RSX (Daniel Seagraves)
> 3. Re: Chat program for RSX (emanuel stiebler)
> 4. Re: Chat program for RSX (ben)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 16 Feb 2026 00:47:31 -0500
> From: Jacob Ritorto <jacob.ritorto(a)gmail.com>
> Subject: [cctalk] Chat program for RSX
> To: cctalk(a)classiccmp.org
> Message-ID: <CA5293FC-836F-4D0C-AE16-9404CF0E7E8A(a)gmail.com>
> Content-Type: text/plain; charset=utf-8
>
> Hi,
>
> I like period correct hardware terminals for authentic immersion feels and
> have been tending to RSX (and UNIX) PDP-11s since my teen years, quite a
> long time now. I keep them in my living room and den, etc. Convincing
> setups that quite look the part. And actually *are* the part; running much
> as though it’s still 1986. Very little emulation “cheating.” Real SMD
> disks, even, sometimes.
>
> Anyway, one of the many fun things I do with them is chat rooms. People
> are like, “you connected here on a WHAT?”
>
> In doing this I find myself often chastised by my esteemed Internet
> colleagues for using such “horrible” computers because “That’s the worst
> possible computer you could pick” (real quote, minus some aspersions about
> power consumption) and “what loser can’t scroll up and look through chat
> that’s more than 24 lines back?!?”
>
> I try to ignore all this in the name of “progress,” but, I mean, they have
> a point. As much as I’m having a nice time with all this, it does hurt
> quite enough already for all the other obvious reasons and then I CAN’T
> SCROLL BACK?!? Come on.
>
> When you think about it retrospectively, this _is_ actually kind of bad,
> right?
>
> So What? Quit the real terminal and computer and use a modern laptop?
>
> Hell no.
>
> It strikes me that scrollback is a silly thing to condemn such a storied
> lineage of computers over, but that’s exactly what’s happening in this
> contemporary vale of tears. My friends think PDP-11s suck because they
> can’t scroll (and, yes, perhaps some other things).
>
> So I say let’s write a scrolling “terminal” program for RSX. Should work
> with serial and telnet (BQT stuff) and DECnet (i.e. $SET HOST XXXXXX).
> Actually maybe it doesn’t even have to know about that layer, right?
> (Thinking as I write this). Spawn whatever command and it buffers the
> output such that you can effortlessly scroll back up through stuff that has
> scrolled past.
>
> Something terribly rudimentary, perhaps, but with at least infinite
> scrollback. Like just a dumb scroll back buffer wrapper thing. Writes to
> / reads from disk as you accrue characters / cursor up.
>
> Heck, this would have been a boon in the day for normal use, right? Like
> having a glass tty and a real paper printing terminal all in one! I can
> scarcely believe it doesn’t already exist.
>
> Would you folks be into helping with it? If not, I’ll try myself. Did a
> bit of this sort of work some decades ago writing a disk imager under RSX
> in MACRO-11 using QIO$ calls, looked up fresh from the orange binders
> sitting there on the couch. Pretty easy.
>
> Should we take from screen or tmux? Or do a clean room concept, you think?
> I hope it can work under RSX and UNIX. RSTS/e, too, anyone? RT?
>
> If you have opinions about this or if it already exists, let me know, pls.
>
> thx
> jake
>
> ------------------------------
>
> Message: 2
> Date: Mon, 16 Feb 2026 07:57:48 -0600
> From: Daniel Seagraves <dseagrav(a)lunar-tokyo.net>
> Subject: [cctalk] Re: Chat program for RSX
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk(a)classiccmp.org>
> Message-ID: <6656C51C-12BD-4D8F-8419-C82A0439A88F(a)lunar-tokyo.net>
> Content-Type: text/plain; charset=utf-8
>
>
>
> > On Feb 15, 2026, at 11:47 PM, Jacob Ritorto via cctalk <
> cctalk(a)classiccmp.org> wrote:
> >
> > Hi,
> >
> > I like period correct hardware terminals for authentic immersion feels
> and have been tending to RSX (and UNIX) PDP-11s since my teen years, quite
> a long time now. I keep them in my living room and den, etc. Convincing
> setups that quite look the part. And actually *are* the part; running much
> as though it’s still 1986. Very little emulation “cheating.” Real SMD
> disks, even, sometimes.
> >
> > Anyway, one of the many fun things I do with them is chat rooms. People
> are like, “you connected here on a WHAT?”
> >
> > In doing this I find myself often chastised by my esteemed Internet
> colleagues for using such “horrible” computers because “That’s the worst
> possible computer you could pick” (real quote, minus some aspersions about
> power consumption) and “what loser can’t scroll up and look through chat
> that’s more than 24 lines back?!?”
> >
> > I try to ignore all this in the name of “progress,” but, I mean, they
> have a point. As much as I’m having a nice time with all this, it does
> hurt quite enough already for all the other obvious reasons and then I
> CAN’T SCROLL BACK?!? Come on.
>
> If you have a decwriter or teletype instead of a glass tty, your scroll
> back is however much paper you can keep around.
>
>
>
> ------------------------------
>
> Message: 3
> Date: Mon, 16 Feb 2026 09:16:34 -0500
> From: emanuel stiebler <emu(a)e-bbes.com>
> Subject: [cctalk] Re: Chat program for RSX
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk(a)classiccmp.org>
> Message-ID: <c0be7865-5bb1-4d7a-8b2d-cbb9955549e0(a)e-bbes.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 2026-02-16 08:57, Daniel Seagraves via cctalk wrote:
> >
> >
> >> On Feb 15, 2026, at 11:47 PM, Jacob Ritorto via cctalk <
> cctalk(a)classiccmp.org> wrote:
> >>
> >> Hi,
> >>
> >> I like period correct hardware terminals for authentic immersion feels
> and have been tending to RSX (and UNIX) PDP-11s since my teen years, quite
> a long time now. I keep them in my living room and den, etc. Convincing
> setups that quite look the part. And actually *are* the part; running much
> as though it’s still 1986. Very little emulation “cheating.” Real SMD
> disks, even, sometimes.
> >>
> >> Anyway, one of the many fun things I do with them is chat rooms.
> People are like, “you connected here on a WHAT?”
> >>
> >> In doing this I find myself often chastised by my esteemed Internet
> colleagues for using such “horrible” computers because “That’s the worst
> possible computer you could pick” (real quote, minus some aspersions about
> power consumption) and “what loser can’t scroll up and look through chat
> that’s more than 24 lines back?!?”
> >>
> >> I try to ignore all this in the name of “progress,” but, I mean, they
> have a point. As much as I’m having a nice time with all this, it does
> hurt quite enough already for all the other obvious reasons and then I
> CAN’T SCROLL BACK?!? Come on.
> >
> > If you have a decwriter or teletype instead of a glass tty, your scroll
> back is however much paper you can keep around.
> >
>
> THAT'S the vintage spirit! ;-)
>
> ------------------------------
>
> Message: 4
> Date: Mon, 16 Feb 2026 09:55:41 -0700
> From: ben <bfranchuk(a)jetnet.ab.ca>
> Subject: [cctalk] Re: Chat program for RSX
> To: cctalk(a)classiccmp.org
> Message-ID: <28c01576-53b9-4478-aea2-74ddb54bb225(a)jetnet.ab.ca>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 2026-02-16 7:16 a.m., emanuel stiebler via cctalk wrote:
> > On 2026-02-16 08:57, Daniel Seagraves via cctalk wrote:
> >>
> >>
> >>> On Feb 15, 2026, at 11:47 PM, Jacob Ritorto via cctalk
> >>> <cctalk(a)classiccmp.org> wrote:
> >>>
> >>> Hi,
> >>>
> >>> I like period correct hardware terminals for authentic immersion
> >>> feels and have been tending to RSX (and UNIX) PDP-11s since my teen
> >>> years, quite a long time now. I keep them in my living room and den,
> >>> etc. Convincing setups that quite look the part. And actually *are*
> >>> the part; running much as though it’s still 1986. Very little
> >>> emulation “cheating.” Real SMD disks, even, sometimes.
> >>>
> >>> Anyway, one of the many fun things I do with them is chat rooms.
> >>> People are like, “you connected here on a WHAT?”
> >>>
> >>> In doing this I find myself often chastised by my esteemed Internet
> >>> colleagues for using such “horrible” computers because “That’s the
> >>> worst possible computer you could pick” (real quote, minus some
> >>> aspersions about power consumption) and “what loser can’t scroll up
> >>> and look through chat that’s more than 24 lines back?!?”
> >>>
> >>> I try to ignore all this in the name of “progress,” but, I mean, they
> >>> have a point. As much as I’m having a nice time with all this, it
> >>> does hurt quite enough already for all the other obvious reasons and
> >>> then I CAN’T SCROLL BACK?!? Come on.
> >>
> >> If you have a decwriter or teletype instead of a glass tty, your
> >> scroll back is however much paper you can keep around.
> >>
> >
> > THAT'S the vintage spirit! ;-)
> Punched cards :)
>
>
> End of cctalk Digest, Vol 1123, Issue 1
> ***************************************
>
