I have a device that plugs into a serial port on a PC and looks like a
disk drive to an Atari 800. Is there such a thing for RT-11? It seems
like it should be possible to write a disk driver that uses a serial
port and some sort of serial protocol to communicate with a PC and make
RT-11 think it is accessing a local disk drive. Has anyone done
anything like that? I have a PDP-11/23 system that is taking up too
much space and I would like to replace it with a small QBus backplane
containing an 11/23 CPU, some memory and a multi-port serial card. I
would use one serial port as the console and another as the "disk"
connection back to a PC. Has this been done before?
Another related question is what is the smallest QBus backplane mounted
in a box with a power supply that will support an 11/23 CPU (M8186), a
memory card (M8044) and a serial port/boot rom card (M8047) and maybe a
multi-port serial card (M8043)?
Thanks!
David
On Jun 6 2005, 15:24, David Betz wrote:
> Is there a description somewhere of all of the BA11-?? variants? It
> seems that there are many of them and they are of various sizes and
> shapes.
Possibly not all, but one of my web pages lists most Q-bus boxes and
backplanes. Additions are always welcome :-)
http://www.dunnington.u-net.com/public/PDP-11/QBus_chassis
--
Pete Peter Turnbull
Network Manager
University of York
>From: ard at p850ug1.demon.co.uk
>
>> Apparently it's OK to spend $200 on a nice set of wrenches, but not
>> OK to scrounge a contemporary PC to read contemporary documentation
>> containers.
>
>The difference being that the set of spanners doesn't need desk space to
>use it, doesn't need maintiaing [1]. and is likely to outlast me.
>
>[1] I have neither the skill nor the test gear to maintain a modern PC.
^^^^^
I doubt that! Maybe you don't have the documentation
but I suspect your knowledge is just fine.
Dwight
>
>
>-tony
>
> Looking for someone who can "rescue" and temporarily store a PDP-11.
> It's about 30 miles west of O'Hare, apparently. I won this at auction;
> the notification didn't arrive, and now that I'm traveling and can't do
> anything about it, they want the beast out of their building yesterday.
I ended up hiring a commercial pack/ship outfit to get this home,
and it was delivered yesterday -- 2199 pounds. Thanks to the folks
who said they would help me load it if I picked it up. Here's a
first glimpse inventory of the haul:
The CPU is a PDP-11/44 with additional labels indicating it was a
Teradyne Teranet ATE Networking System, whatever that is. In addition
to the CPU, the tall cabinet (purple and orange DEC banner across the
top) contains a serial mux, a DEC battery backup, two RL02s, and an
additional card chassis with some damage to its backplane wiring.
The latter contains a pair of memory boards (Mostek), and some
Teradyne-built items; I don't recognize the bus -- two edge connectors,
each wider than qbus. It doesn't look like the unibus cards I've seen.
The first small cabinet (9764, I think?) contains three RA81 drives;
one is labeled 'bad hda'.
The second small cabinet (also 9764) contains a TU80 and an RA81.
The RA is labeled 'bad motor / bad hda'.
Also included are a Decwriter, a DataProducts line printer, and
a VT131.
It looks like the cabling is pretty much intact. Whoever
decommissioned this system did a decent job of tucking cables up into
the backs of the cabinets. I figured with my luck someone would have
just cut them, so I get to be happy now.
I haven't had the CPU out on its rails yet, so I don't know what's
inside. I'm going to have to work on power outlets before I can
even try to run this beast. (And yes, I intend to look through the
archives for tips on proper pre- and first-power-up etiquette before I
blow anything up)
Guess I have a summer project now. (Like I need any more projects. :-)
De
>What is the "proper" name for the Tandy Color Computer? Is it that? Or
>is it "Tandy TRS-80 Color Computer"? Or is it "Radio Shack TRS-80 Color
>Computer"?
>
>I guess it also depends on what model we are talking about, so let's say
>the original and the CoCo2. I know the CoCo3 was pretty much labeled
>Tandy by then.
One answer is "BOTH", because TRS actually means "Tandy Radio Shack".
However I assume you are asking about the labels on the machine and the
printing on the boxes.
The "Radio Shack TRS-80" was dropped/switched to "Tandy" on the labels
sometime during the CoCo 2.
I have a total of 8 Color Computers in my Collection:
#1
Big box
Large (deep) and silver in color
"Radio Shack TRS-80 Color Computer"
Separate square sticker reading "4K RAM"
little square chicklet keys
#2
Same box/size/color/labels except "32K RAM"
Keyboard bas been upgraded, but I have the
original which is the same as above.
#3
Same box as above
Same size, but white in color.
"Radio Shack TRS-80 64k Color Computer"
No memory size sticker (64k is on main label)
Bigger/square keys, but still fairly flat.
#4
Much Smaller box
Smaller, not nearly as deep, white in color
"Radio Shack TRS-80 Color Computer 2"
No memory size sticker on top
Same keys as #3
#5
Don't have the box.
Same size as #3, white in color
"Tandy Color Computer 2"
No memory size sticker on top
Full sized keys (taller)
#6-#8 (all the same)
Slightly smaller box than #3 (shorted lengthwise)
Same size as #4, white in color
"Tandy 128k Color Computer 3"
No memory size sticker on top (128k on main label)
Full sized keys similar to #5, although there are
a couple of new ones in the lower right corner.
I've been meaning to post an inquiry about the various CoCo
models ... Aside from different memory sizes and standard/extended
BASIC, are there any physical variants other than I have described
above?
I thought that all CoCo1's were silver with the chicklet keys
until I just recently got #3 which was quite a suprise to me.
The (Canadian) Radio Shack catalogs go directly from #1/#2
in the 1983 issue to #4 in the 1984 issue. I do not recall
ever seeing a white CoCo1 with square keys before...
Regards,
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
>From: "Dave Dunfield" <dave04a at dunfield.com>
>
---snip---
>
>If the above gets you nowhere, then it's just a matter of sitting down with
>the schematic and a scope and following the signal from that switch all the
>way through to the bus at some point you should see that the zero from the
>switch is not making it through a component or connector. I don't recall the
>details of the IMSAI panel, but you might have to trigger on the read strobe
>to catch the signal being clocked through the panel.
Hi
Actually the address are a little different. The processor
actually generates the address. The front panel generates a
JMP instruction with the address to the CPU that then
generates the address to the bus. The front panel has a simple
sequencer to generate the JMP, AddrLow, AddrHigh sequence.
Dwight
>From: ard at p850ug1.demon.co.uk
>
>> By the way, the power supply, so far, has tested fine. I'm going to look
>> for any ripple with the scope later today. I've never done that test --
>> should I DC or AC couple the scope for that test?
>
>AC coupled. That's really what AC coupling is for -- you want to ignore
>the steady DC level (of several volts) and look at the (hopefully) much
>smaller AC ripple on top of it. To do that you need to turn up the Y
>sensitivity on your 'scope, and unless you have a differential comparator
>input or something, you won't be able to keep the trace on-screen with DC
>coupling.
>
>Don't worry too much about ripple on an S100 supply. The S100 supply is
>not regulated -- the regulators are on each of the boards (the 8V input
>is designed to be regulated down to 5V, etc). The regulators should take
>care of small amounts of ripple on the backplane supply lines.
>
>-tony
>
Hi
For this particular test, using DC coupled is probably
best. As Dave mentions, you just don't want the voltage
on the unregulated 8 volt line to drop below 7 volts.
It can tolerate a relatively large ripple.
Dwight
I thought I had a manual, and I do, but it's for a Mullen "TB-4", not your
"TB-1". And interestingly, it has neither a schematic nor a circuit board
drawing (layout).
These were very common boards, if anyone has the TB-1 manual, we should get
it scanned to a PDF file (I volunteer, but I need the manual).
>From: "Jan-Benedict Glaw" <jbglaw at lug-owl.de>
>
>On Fri, 2005-06-03 14:57:15 -0500, Jim Leonard <trixter at oldskool.org> wrote:
>
>> But that's not your domain/responsibility. The PDF should have been
>> perfect by the time it got to you -- PDF is a final end-destination format.
>> If the scans needed touching up, they shouldn't have made it into a PDF in
>> the first place.
>
>Wrong IMHO. As my thesis is the pure four-dimensionalism of preserving
>content, it's legal (and I'd even *ask* for it) that a good preservation
>format will allow later enhancements. Be it fixing some spurious black
>pixels, adding textual/OCRed content or whatever.
>
>The person that does the scanning isn't probably the one who actually
>prepares the "end-format". The "end-format" should be the result of an
>access to the preserved data, not the result after preservation.
Ahh. Someone else that has some common sense besides Sellam and me.
Dwight
>
>MfG, JBG
>
>--
>Jan-Benedict Glaw jbglaw at lug-owl.de . +49-172-7608481 _ O
_
>From: ard at p850ug1.demon.co.uk
>
>>
>>
>> OK, I pulled the front panel appart tonight and I found out that whoever
>> owned this model colored the silkscreen with magic marker. Bogus!
>
>Try wiping it with propan-2-ol. That will remove most 'magic markers' and
>may well not damage the original printing.
>
>-tony
>
Hi
I believe the original is photo emulsion and not printed.
Dwight
