Simon,
Die checked the filter elco's.
You should check the leakage current and ESR values. If the mosfet is running hot you should check the board for shortcuts.
Tantalum caps have a habit of getting shortened when they get aged. Also a not working driver can cause a large current, this can be checked with a scope. Check the signals at the base of the drive transistors. I suppose you checked the voltages for ripple and noise.
-Rik
-----Oorspronkelijk bericht-----
Van: "Simon Claessen" <simski at dds.nl>
Verzonden: ?13-?2-?2014 10:00
Aan: "On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Onderwerp: Re: LA12 correspondent
On 12-02-14 23:18, Tony Duell wrote:
> In whuich case it's almost certainl the right sort of part. My
> experience suggests that SMPSUs fail for may more trivial reasons than
> having a MOSFET fitted in palce ofr a bipolar transistor.
>
>
The mosfet runs hot, even with the original cooling, and the paper is
not advancing, so there must be something wrong somewere else in the
machine. I actually would love to find out what type of transistor was
there originally relabeled as digital part # 151278200
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
hello all. i happen to have a dell optiplex gx50 and i got 98 on it and
when i started installing stuff to it i got so far then the os stopped
booting at all and black screened. i wish i could find a good windows 98
computer or setup. if anyone could help out let me know
>Date: Wed, 12 Feb 2014 08:43:43 -0500
> From: allison <ajp166 at verizon.net>
> To: cctech at classiccmp.org
> Subject: Re: [u-u] Someone's looking for old software
> Message-ID: <52FB7A8F.4080306 at verizon.net>
> Content-Type: text/plain; charset=ISO-8859-1
>
>
> >> Will VAXELN even run on a 3100 or a 4000? I
> thought it was limited to Q-Bus
> >> systems, but won't be surprised if I'm wrong.
> >>
> >
>
> It runs on any VAX. However its not a OS. Its
> closer to a IO subsystem
> and scheduling
> package (RTOS). Like many RTOS packages the basic
> system is fairly
> useless and not
> a user environment. Its used to make real time
> systems. Examples that
> used it were
> LPS40(qbus), LPS20(not Q), LPS32(not Q) and the terminal
> software for
> the VS2000
> (very not Q). If the bus/IO structure is not Qbus or
> other DEC standard
> bus then IO
> is up to the developer.
>
> Allison
VAXELN is/was a host/target setup for developing distributed
realtime VAX applications (ELN = Executive for Local Networks).
Hosted on any sensible VAX/VMS system, with targets being a
subset of VAX, MicroVAX, VAXstation systems. And a few oddities
too (e.g. RTVAX300 VAX-in-a-module, KAV30 RTVAX300-on-VMEbus,
rtVAX1000 (KA630-variant in a MicroVAX2 chassis), etc.
Obscure targets without publically available VAXELN support (?)
include the aforementioned LPS32 and LPS40 VAX-powered printers.
The SPD seems to be hard to find online, as does the VAXELN
Technical Summary, so what follows is from memory. The usual
suspects do seem to have some of the VAXELN docs online in
decw$book format.
The host and target might be separately licenced.
Early VAXELN applications could be written in a multi-threaded
variant of PASCAL called EPASCAL. Later, other standard VAX
languages were supported too: Ada, C, maybe Fortran, the usual
Pascal. Or VAX Macro.
The runtime environment was a dedicated RTOS environment, not VMS
(e.g. no demand paging) although some VMS-compatible facilities
(DECnet, RMS) and routines (some LIB$)were offered.
You compiled your application in the usual way, and linked it with
VAXELN-specific libraries using the usual linker.
The VAXELN system builder was then used to build a bootable system
image. A system image would include the hardware-specific kernel and
any required VAXELN device drivers. Any optional facilities
(VAXELN distributed name service, networking using DECnet and/or TCP,
CLI, Xserver, debug) would be combined with any required user
applications to make a bootable system image file
Booting was supported over the LAN (MOP, maybe bootp), from disk, and
in an odd few cases, from ROM.
A VAXELN source kit was sold at one stage, though it was far from
essential. Pretty much the whole target end was written in PASCAL.
In the early days VAXELN had its own threads-aware debugger (hosted on
VMS and networked to the target).
Once VMS DEBUG got that capability (which came initially with DEC
Ada? sometime around VMS V4?) VAXELN targets could be debugged remotely
using the standard VMS debugger. Deep joy.
Iirc, VAXELN V4.3 or thereabouts used to be on CD in the 1990s (1993?).
There were a couple more versions after that, but no huge changes I can
remember.
When Alpha came along, VAXELN was left behind. DEC worked with Wind River
to get a version of VxWorks for Alpha (VxWorks was an "industry standard"
RTOS, somewhat different in concept to VAXELN). Both claimed to have POSIX
compatibility for the RT stuff. A thin VAXELN veneer was added on top of
VxWorks for those who might be interested.
The product became part of DEC's Embedded+Realtime Group, which was
sold off to SMART Modular Technologies, in the late 1990s (?), and the
product subsequently vanished. I haven't recently been able to establish
the product's current status, though I didn't try real hard.
It was a great RTOS if you wanted to think more about the application
design and less about the intricacies of device drivers and networking and
other such traditional RTOS trivia. I'm told its concepts mapped nicely onto
the "channels and pools" from "Communicating Sequential Processes".
Be interesting to know what lies behind the original enquiry from LinkedIn.
I may be able to offer more info if necessary. It might not be quick, and
the formatting may be messed up again (sorry).
Hope this helps,
regards
John
>
>Will VAXELN even run on a 3100 or a 4000? I thought it was limited to Q-Bus
>systems, but won't be surprised if I'm wrong.
>
I have come across a VAXELN image for a VAXStation 2000 which I think
implemented some sort of X Terminal on it.
(While not Q-Bus based, at least some of the VAX 4000 range do have facilities
attach Q-Bus periperals.)
Regards,
Peter Coghlan.
Does anyone have the setup and documentation for this MF-300 CCA? I would
like to install it in my HP9836C and run the Infotek BC204 Basic Compiler ,
but I do not have any info on how to set the DIP switches.( there are 9
switches.
--
e-?
>
>I have a box of them, used, along with the monitor boards and almost all
>vt1xx logic boards. I have some of the boards handy, but the rest I won't
>be able to dig out for a while due to more pressing personal priorities. I
>will post when I find them.
>
Hi Paul,
I have been looking for a flyback transformer for a VT220, part number
16-26299-01 (or possibly 16-21181-01 which appears to be the same thing with
a different mounting arrangement).
I would appreciate if you could keep a lookout for one of these when you are
searching.
Regards,
Peter Coghlan.
Greetings,
I've been hard at work on an OS/8 system handler that negotiates block
transfers between a PC running a special disk server. The two are currently
working great! I was able to use the BUILD utility to make my own OS/8 V3D
disk and boot from it. I then thought that it may be possible to take an
existing RK05 image and replace the bootloader and system handler with my
own. Sure enough, it works!
Check it out: https://www.youtube.com/watch?v=YkqVJ6ShV5A
I'll be releasing the source code for all of this within the next few weeks
as I make minor changes (and mostly tidy it up).
A few details: the handler resides in one page and talks to the server to
negotiate the transferring of pages. To keep the handler small, I'm
offloading as much stuff onto the PC as possible. There's no error
detecting (although this hasn't been an issue for the millions of bits I've
sent thus far) and the features of the handler are pretty basic. The disk
server is written entirely in C and has been successfully compiled on Mac
OS X and Windows under Cygwin.
The handler sends serial data to an M8650YA (currently addressed at 40/41,
the aux TTY addresses) operating at 19200 baud. This is pretty slow still,
as you can see from the video. But it's usable! And it's bound to get
better with a few more improvements.
To bootstrap the system, the RIM loader is toggled in as the primary
bootloader, and a secondary bootloader is sent in RIM format. Start the
system at 0020 after that, and it'll boot right up.
In summary, anyone with a spare M8650, M8655, or other serial card can now
boot OS/8, even if you don't have an RK05, DECtape, RX01/02, etc.! If you
have a parallel I/O card, another handler could be made for even faster
transfers, I imagine. This would require some extra hardware, though.
Let me know if you have any questions. Again, I'll see about distributing
the source in a couple of weeks, or as I have time.
Kyle
Vintage Computer Festival Southeast 2.0
May 3,4 2014
The Atlanta Historical Computer Society and the Computer Museum of
America are pleased to announce the second annual Vintage Computer
Festival Southeast. We have selected the 3rd and 4th of
May to make it easy for people to attend both VCF East and VCF
Southeast this year.
The venue will be the same former CompUSA store in Roswell GA as last
year. This year's exhibit space will be greatly enlarged over last
year, occupying the whole retail space of the store. About 2/3 of the
space will be the exhibition LINK ? Personal Computing from Switches
to Pockets. The exhibit is a journey from the present back to the
Kenbak-1. The remaining 1/3 of the retail space will contain hobbyist
vintage computing exhibits. For those who missed last year or who
would like to see it again, the Apple Pop-Up museum from last year's
festival will again be available.
The popular retro-gaming area and introduction to soldering activity
will be available again. This year, we are also working to bring in a
number of vendors, assemble a stellar slate of speakers, and offer
workshop experiences. Of course, the kids' scavenger hunt will be
back this year too.
More details as they become available. Hope to see you all there.