>
>Subject: S-100 power supply transformer
> From: "Andrew Lynch" <lynchaj at yahoo.com
<http://www.classiccmp.org/mailman/listinfo/cctalk> >
> Date: Sun, 17 May 2009 16:51:44 -0400
> To: <cctalk at classiccmp.org
<http://www.classiccmp.org/mailman/listinfo/cctalk> >
>
>Hi! Does anyone know of an available transformer suitable for making an
>S-100 power supply? I need 120VAC input and 10VAC output and +/- 18VAC
>outputs.
>
>The best I solution I can find is two separate 80VA transformers; one
>parallel 10VAC output and another 36VCT output which can be configured for
>+/-18VAC outputs.
Try closer to 8V RMS rectified that will be more depending on load.
Same to the other two. Look up the calulations and see. FYI you also
talking for the 8V line 60,000 to 150,000microfarads (at 15-25V) and
the other two more like 10,000 to 20,000 (at 30V min) microfarad
capacitors..
[snip]
-----REPLY-----
Hi Allison and the others that replied. Thanks for the information!
I am currently using a kludged S-100 power supply built from repurposed
SMPSUs. It works fine but involves three separate parts. I suppose if I
could find a +/-15V dual output unit I could combine two but what I have
works fine. However, I've never seen an off the shelf single unit SMPSU
that supports S-100 voltages that does not require adjustment. A
+7.5V/+15V/-15V or similar would be ideal but I've never seen one available.
Reusing SMPSUs works but each solution is essentially a custom installation.
Tweaking surplus ATX supplies sounds appealing but for most people screwing
around with SMPSUs is hazardous and unique to each type of power supply.
Generally, I stay out of the SMPSU chassis unless there is a really good
reason to be there.
I wrote up my plan for the S-100 linear power supply. It got rather long so
instead of posting a mini-manifesto on the list if you are interested you
can read it here:
http://n8vem-sbc.pbworks.com/f/S-100_linear_power_supply_plan.html
Any comments, suggestions, questions are appreciated.
Thanks in advance and have a nice day!
Andrew Lynch
Jay writes:
> I'm concerned if it might cause Tim issues. If he got excessive bandwidth
> charges, I will pay them, no questions asked. However, I am a bit concerned
> if this would cause a problem. Anyone who has signed up as a bitsavers
> mirror as been advised that they must make their mirror public, and they
> must be able to sustain a reasonable load (fair share) of bandwidth -
> otherwise they shouldn't be mirroring it (this is just meant to make it fair
> for everyone, including me). That's not to say that 1/2 the load is fair, it
> isn't. But a suprising number of people hit the bitsavers site and then
> select their favorite mirror, so I wouldn't think it would have made that
> much difference. Let me know if so.
I may have seen an uptick in net usage during that time (Friday and Saturday?),
but it was not severe. The pipe was at 100% for several hours... but it's
at 100% for several hours most any day anyways.
Nothing at all compared to being slashdotted :-)
Tim.
Al wrote:
>> Yup, redirected to trailing-edge.com.
>>
>
>That is really bad. Tim will not be pleased.
It's not so bad. I'm quite used to getting slashdotted. The net bandwidth out of my site is really tiny but it's fundamentally there to serve good stuff up, and without a doubt bitsavers is good stuff.
I suspect folks trying to download, oh, say the 1981 Tektronix catalog would be very dissatsifed with the bandwidth out of my site, if they want the document in faster than a couple hours.
Occasionally we get into discussions about mirroring for geographic redundancy and I support all efforts to do so, even if it sucks up my bandwidth.
Only rarely do I stay up at night worried about bandwidth. But I do stay up at night worrying about what would happen if some server filled with good stuff became suddenly unavailable. We have archive.org and Google's cache as good starts but I think they don't necessarily suck up tape images. I do notice that google has sometimes been building its indices with OCR from scanned PDF documents.
Tim.
Hi all
?? Those of you who know me, know that I have a rule that basically make me attempt to get rid of stuff that I have not used after a certain period of time.
?? I have a second fully functional IMSAI-8080 (http://www.michael-george-hart.com/computerscience/imsai8080-z80.html) that has been sitting around doing nothing since completed my last IMSAI-8080 project (http://www.michael-george-hart.com/computerscience/imsai8080-8088.html)
?? Given my other S-100 projects, ALTAIR 8800b repair and restoration, and porting LINUX to my CS-250 I don't foresee really doing anything with this particular IMSAI-8080 for at least another year to two years maybe as much as three years from now.
?? I have had this IMSAI-8080 since 1996/1997, which I got from a Electronic parts/component store. The store used it to maintain their inventory along, mail, billing etc from about 1975/1976 until it simply stopped working. (That was the story told to me.) It sat in their store from the day it stopped working until I came across it in 1996/1997. I made some simple repairs to the memory and its been working since that time.
?? The only issue with it is there are some minor alignment problems with the between the floppy drives. Other than that the system has always booted without issue.
?? The person who purchase the system from me will get all the manuals for all the boards in the system and the floppy drives. Also to be included is the IMSAI-8080 Manual and a number of IMSAI-8080 period related fliers. I will be sending the 50 or so floppies that originally came with the system when I first took possession of it .
? Again this is a fully functional IMSAI-8080 in near mint condition.
http://www.michael-george-hart.com/image/s-100/imsai-1/dsc02565.jpghttp://www.michael-george-hart.com/image/s-100/imsai-1/dsc02567.jpghttp://www.michael-george-hart.com/image/s-100/imsai-1/dsc02572.jpg
I am looking to get $2000. If no one is interested I will put it on e-bay and see what the market tolerate. I think that my price is a good deal consider the crap that I see people paying $1600 to $2500 on e-bay for systems that don't even work or can boot into CP/M-80
I intend to place the system on e-bay Wednesday morning is no one here gives a my expected price.
Let me know if you are interested
Michael
Michael Hart
201-290-3796
michael.george.hart at gmail.com
PS.
?? The total weight is about 100lbs. I will probably have to ship everything I mentioned above in 5 different boxes. You pay for shipping cost.
If possible I would prefer whomever purchases the system come an pick it up the system so they can confirm the functionality to their satisfaction for themselves. I still don't trust UPS/FedEx or USPS for safely get the system no matter how well I pack the system.
"bfranchuk at jetnet.ab.ca" <bfranchuk at jetnet.ab.ca> wrote:
> Johnny Billquist wrote:
>
>> > (And to make it clear: hardware flow control is definitely not possible
>> > towards a PDP8)
>
> I use it all the time ... serial device is turned *ON* or *OFF*. :)
Nothing prevents the PDP8 from sending data even if your serial device
is turned off. :-)
> What is needed is the reader run relay more likely than not.
Hmm. The paper tape of the ASR33... Was there some signal run in
parallel for the reader run? What did you hook the other end to then?
The KL8-JA (and KL8-E) don't have any more signals that I can remember
offhand. There was an option for the KL8-JA (called KL8-M I think) which
implemented partial modem signaling, if you needed that. Never seen one
in real life, and I can't remember if I ever read any documentation of it.
But you'd most likely need software to actually implement the signaling
anyway. It won't be a hardware-only solution...
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
Rick Murphy <rick at rickmurphy.net> wrote:
> At 05:17 AM 5/17/2009, Johnny Billquist wrote:
>> Chris Elmquist <chrise at pobox.com> wrote:
>>
>>> I may have missed some facts earlier in this thread-- but does the
>>> system
>>> obey hardware flow control such as CTS? ie, if CTS is low, will it be
>>> blocked from transmitting? If that is obeyed by all of your OS and
>>> software, then it is not hard to build a microcontroller that would sit
>>> between the system and the terminal, adding the delays you need on <cr>
>>> while buffering for and hardware flow controlling back toward the PDP-8.
>> In general, when talking about DEC equipment, the answer to that
>> question is *always* no, for the simple fact that DEC didn't do
>> hardware flow control. Hardware flow control is actually against the
>> RS-232 spec, and DEC didn't abuse standards (unlike most other companies).
>
> And, of course, there's a pretty good chance that this VT05 is
> connected via 20ma, not RS232.
> (Assumption based on the fact that there's an easy fix in the KL8-JA;
> given that this hasn't been used to fix the problem, it's probably not
> an omnibus computer. Pre-8/E serial devices were often current loop.)
Assumption wrong. :-)
The original posted have a KL8-E, which is software compatible with the
KL8-JA, but don't have the filler fix that the KL8-JA have.
They are both omnibus devices.
The KL8-E is actually kindof cool, since it implements a UART in
discrete logic. One side effect of that implementation is that you can
send a break character, since the transmit shift register is always
loaded immideately, even is a character is currently being transmitted,
and the stop bit is also shifted through the register, thus you can
"overwrite" the stop bit with additional data.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
I had been working on a deal with him for an apple iigs and some other
things. I sent him some money though paypal, then nothing happened.
Last I heard he had moved to Austin Texas. I'm not sure whether
that's true or not. After 30 days I disputed the transaction and
paypal sent me back the money which was enough to get him to respond
to my emails. He sent me an apologetic email and said he still had
the computer if I was still interested. (I'm not)
The email address you have is the same one I have which he used to
send me the email from Austin. I'm not sure if they have comcast in
Austin, but I sort of doubt it. I can think of a few technical
scenarios where this is possible. But my guess is that he still lives
in Washington.
brian
On Mon, May 18, 2009 at 10:37 AM, Mark Tapley <mtapley at swri.edu> wrote:
> Hello all,
> ? ? ? ?I lost contact in the middle part (at the most embarassing moment) of
> a deal for a Mac IIci with a Michael Green, last known email (account no
> longer exists)
>
> ? ? ? ?michaelgreen42 at comcast.net
>
> last known address
>
> ? ? ? ?4409 67th Ave. E Fife Wa 98424
>
> but said to be moving shortly. Any assistance reestablishing contact would
> be well appreciated.
> --
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- Mark ? ? 210-379-4635
> -----------------------------------------------------------------------
> Large Asteroids headed toward planets
> inhabited by beings that don't have
> technology adequate to stop them:
>
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Think of it as Evolution in Fast-Forward.
>
Hello all,
I lost contact in the middle part (at the most embarassing
moment) of a deal for a Mac IIci with a Michael Green, last known
email (account no longer exists)
michaelgreen42 at comcast.net
last known address
4409 67th Ave. E Fife Wa 98424
but said to be moving shortly. Any assistance reestablishing contact
would be well appreciated.
--
- Mark 210-379-4635
-----------------------------------------------------------------------
Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:
Think of it as Evolution in Fast-Forward.
"js at cimmeri.com" <js at cimmeri.com> wrote:
> Going a bit OT from archiving RX50's... I wonder how MicroRSX differed
> from full RSX11-M, which itself was quite compact?
Don't be fooled by the "Micro" in MicroRSX. It is a referral to that the
OS was custom adapted for the MicroPDP-11. MicroRSX is actually rather
big. It's a customized version of RSX-11M-PLUS for a specific set of
hardware. As such, it is delivered pre-compiled, and you cannot run
SYSGEN. Instead, it has a configuration program that runs on boot, which
can adapt it to the specific needs you have. But the possibility of
adaptations are limited. You don't get any sources, and if I remember
right, you don't even get MACRO-11 or TKB with it. Those were options
you'd have to pay extra for.
It's more of a turnkey system for a specific task. You bought a
MicroPDP-11, MicroRSX, some application that you wanted to use, and just
used it.
> It's truly amazing what was once done (in this case, by David Cutler)
> with so little memory. Back in 1999, Lars Poulsen wrote:
>
> "RSX-11D soon grew too large to fit on a 32KB (16KW) machine.
> David Cutler decided that it was possible to implement the same
> services with much less code, starting from scratch, and went on
> to do just that. In 18 months, he basically wrote and debugged
> the RSX-11M kernel. The system was released in source form, and
> with conditional assembly could be configured at compile time
> for any hardware from 8KW 11/05 to a full-house 11/45.
> Over the years I worked on RSX-11M based system integration,
> I eventually got to take a look at most of the modules of 11M,
> and Dave Cutler's name was in the header of each one! "
Yeah, RSX-11M is really nice, small and beautiful. And yes, Cutlers name
is all over the sources.
RSX-11M-PLUS, which is a superset of -11M also share the same code base.
Johnny
>
> Then, to hear Mr. Cutler talking as he does here, was quite a surprise:
>
> http://www.amd.com/us-en/Weblets/0,,7832_8366_7823_8718%5E7839,00.html
>
> jS
>
>
>
>
> Tobias Russell wrote:
>> > I've put up the microRSX-11 distribution floppies for anyone who is
>> > interested. They can be found here:
>> >
>> > http://www.pdp11.co.uk/2009/05/17/microrsx-11-rx50-distribution/
>> >
>> > I've started to play with getting this up and running on simh. It seems
>> > to boot the install floppy ok, although it hung after I selected install
>> > from the menus. If anyone has better success, please let me know as I
>> > would like to get this up and running.
>> >
>> > All the best,
>> > Toby
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
I am looking for a DATAC 1000 SBC. Anyone have one? These were popular
with members of the Philadelphia Area Computer Society (PACS) in
1977-1978. I would like to learn more about what kinds of projects
people did with them. Maybe get a few pictures. I have a few articles
on this trainer/SBC but not much else. I have already spoken with some
PACS members about it, but none has one.
Bill
