http://classiccmp.org/pipermail/cctalk/2010-January/282022.html
It always suprised me that hre BBC micro used the 6502 rather than the
6809. By the time the Beeb was designed, Acorn had made a 6809 processor
board for their System machines, so they must have had experience with
the chip. THe Beeb is nice, but a Beeb with a 6809 processor would have
been something else :-)
-tony
Hi! When I designed the N8VEM 6809 host processor it is loosely based on an
article I read for the BBC computer called "Dragon in the tube". I am not
very familiar with the UK microcomputers but apparently 6809 "coprocessors"
were fairly common peripherals on their Z80 and 6502 designs. I used a
similar concept for the N8VEM to allow its Z80 SBC to access the 6809 as a
"host processor" peripheral on the ECB.
One of the builders was able to get CUBIX running on the N8VEM 6809 host
processor using the Z80 as its "IO processor". However, I can see how the
implementation can get confusing because it is either a Z80 based system
with a 6809 coprocessor or a 6809 based system with a Z80 IO processor. In
reality it doesn't really matter but it's a matter of perspective.
The N8VEM 6809 CUBIX implementation allows the use of ECB peripherals like
IDE, video, floppy, serial, parallel, etc but it requires the Z80 to serve
all the IO based on 6809 commands. I added the 6809 IO mezzanine board
(power, ACIA, PTM, 2 VIAs, expansion bus) to give builders the option of
using the 6809 host processor as a stand alone computer or to add separate
IO to the N8VEM system when connected to the bus. The idea being to let the
6809 host processor interact with the outside world using its own IO and
only involve the Z80 when absolutely necessary.
The hardware seems to work OK but we'll see where the software goes. I
think with CUBIX the 6809 N8VEM system becomes a lot more practical. The IO
mezzanine fits on top of the 6809 host processor. You can see some photos
here. These are out of date but give a good idea. Recently I fitted an
improved serial cable and the nylon standoff hardware. Also the PTM seems
to be working and that's good.
http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder¶m=m6809
I have many 6809 host processor and IO mezzanine PCBs so if anyone is
interested please let me know. This would be a great opportunity for anyone
who would like to do some 6809 hardware and software hacking.
I think the N8VEM 6809 host processor is the only system I am aware of other
than Dave's homebrew that is running CUBIX. There maybe some other homebrew
systems out there too I can't find them after some searching.
Thanks and have nice day!
Andrew Lynch
Hi guys,
I'm trying to get my hands on a 5.25in double-sided 40 tracks per side
"360K" floppy drive with the Shugart or IBM PC 34-pin connector (either
edge connector or pin header is fine). Does anyone have a spare they'd
like to part with? Slight preference for Teac or Mitsubishi, but
anything will do at this point.
I've checked Ebay, there are tons in the US (complete with "seller does
not ship internationally, don't even ask"), but the only ones I've seen
>from UK sellers are parts scalpers wanting stupid money for them (?149
"sold untested with no guarantee"? really?).
A BBC Micro 40-track drive would also be fine -- as long as it's native
40-track, not 40/80 track switchable or double-stepping (an 80-track
drive mated to a PCB which double-steps the head). Cumana, Viglen and a
few other companies made these, they were extremely common a few years ago.
I'm on the verge of getting DiscFerret write support working (at least
for UNIX PC disks) but the sodding thing won't read anything my 80-track
drives have written!
I'd rather not borrow the 3B1's drive - the DiscFerret is experimental
and a benchtop lashup is hardly an ideal scenario.
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
Dave,
> If the internal screen is fine then the syncs are at or close to the
> proper frequency, so any problems are going to be around the NTSC
> modulator, which would be fun to debug without a scope...
I do have a scope- poking about down in the chassis is difficult- I don't have
an ISA extension card. The composite trace drops down to the back side of the
card, comes up through a resistor, goes to the light-pen header, through another
resistor and vanishes into the middle layer. I could start just prodding with my
meter to see where it re-surfaces... but, well, yeah. A schematic would make
that easier.
The image on composite "tears" horizontally. I made a video of it, hooked up to
my TV set in the living room: http://youtu.be/a4jcKiSwUos
> On the other hand whilst I have never tried the Composite on CGA, but I
> have tried comparable modes on several other computers, including my
> rather old Atari STE, and a very modern Raspberry PI and it sounds like
> its working (almost) just fine. The composite out on CGA cards always
> was pretty useless, and "legible, just" pretty much describes any
> 80-colum output on composite. Try 40 a column mode (2 or 3)...
That's in 40-col mode, above. In 80-col it goes into a text mode rather like
MDA, which I haven't scoped to see if it's not present at the jack, or if the TV
refuses to display it. It's remarkably crisp, considering.
On a regular TV set (older, cheaper, no-name set)-
http://www.flickr.com/photos/philandrews/8657681921/
Above was trying to display this-
http://www.flickr.com/photos/philandrews/8660917851/
Admittedly that was all unbalanced, but I'm sure it should be a little better
than that.
> (Oh and my experience is with PAL, NTSC would probably be worse.....)
> If you have a TV with a SCART then the circuit below would work..
> http://www.electroschematics.com/377/
> but I guess you are in the US and and your TV will have CYMG inputs.
> Actually that circuit would probably work with CYMG but the colours
> would be wrong.
Yeah, I should have said. I moved out here to the States a number of years ago
now. My TV sets have all the usual "modern" inputs for here, CATV (NTSC
modulated), Composite-in, YPbPr component, HDMI and the one in the bedroom has a
VGA-in.
> If have a modern LCD TV with a VGA input you could try something
> similar, but leaving the syncs separate and feed it into the VGA. This
> might sound daft but often LCD TVs will sync to normal TV on the VGA. IT
> doesn't work with monitors, but it does with some TVs. As a quick and
> dirty test you could just use 470 ohms on all leads and omit the "I"
> line....
I can give that a try, but it's a band-aid to the symptom. I've got another
machine with CGA out and the TV displays it nicely. I'd like to be able to use
the composite-out because the machine has several games on that make use of the
timing inconsistencies in NTSC to create a larger color palette than the
standard 4. That would, however, be useful for other applications. It's been a
while since I've seen a SCART connector..!
> Dave
> --
> Dave Wade G4UGM
> Illegitimi Non Carborundum
>
>Subject: VT-180 (Robin) EPROM images?
> From: "Robert Armstrong" <bob at jfcl.com>
> Date: Sat, 10 Mar 2007 20:23:04 -0800
> To: <cctech at classiccmp.org>
>
> Does anybody have images of the v2.1 Z-80 firmware for the VT-180 (aka
>Robin) ? At least, I think 2.1 was the last version ever released. They
>should be DEC part numbers 23-017E3-00 and 23-021E3-00.
>
>Thanks,
>Bob Armstrong
I have enough of them laying around I could supply the actual roms. I've
never imaged them as It's easier to replace the code outright.
Curious why are you looking for them?
Allison
Yay! Woo Hoo! Great news! We have S-100 68K CPU running!
Once this project is working maybe we could take another look at the 68360
P1 and/or 68040 SBC?
This is really great news! Please post pictures and notes on the wiki!
Let's get the word out!
Thanks and have a nice day! You've already made mine! w00t!
Andrew Lynch
PS, this project has been in work for 2 years+ so I am very happy to see it
working.
From: n8vem-s100 at googlegroups.com [mailto:n8vem-s100 at googlegroups.com] On
Behalf Of yoda
Sent: Monday, August 12, 2013 10:40 PM
To: n8vem-s100 at googlegroups.com
Cc: monahan at vitasoft.org
Subject: Re: [N8VEM-S100:1808] S-100 68K CPU board V3
Hi John
Thought I would give an update - found the problem with memory - it turns
out pin 1 of U2 on the board had a cold solder joint - guess it finally gave
out. Reflowed the solder - the ground plane is a pretty big heat sink
around pin 1 and can easily get a cold solder joint. Any ways after
repairing that and playing with jumpers and switch settings I have 1 Meg of
memory working with the S100-68K-V3. I also have the oscillator at 16MHz
so the CPU is running at 8MHz and is a buss master. I am using the short
S100 mother board from the group so it may have better noise immunity than
the 22 slot mother board like you are using. I will do some more testing
and want to boost the memory to at least 2 Meg for some experiments. I
will get started next on the new monitor and getting data to load from the
IDE CF card. Looks like I am on my way to getting CP/M 68K ported. I
have a little clean up to do in a couple of areas (upgrade to latest
compiler code, etc).
Dave
>> >> [...non-ancient disk on Unibus machines...]
>>
> > I'm surely not the only collector who would be willing to pony up
> > some $$$ for such a project....
>
I would certainly pony up some $.
I built my own IDE->S-100 interface (with guidance from my amazing friend, Allison P); it was very easy, hardware-wise.
What makes IDE to Qbus or Unibus interfacing so difficult? There must be reasons, otherwise it would have been done by now.
JS
At 08:34 AM 30/09/2013, you wrote:
>Near Cincinnati, Ohio, USA
>
>
> What connection is on the computer? I am assuming it is a
> type with nine holes and six pinjs in two rows.
I turned up two monitors of the ones easy to get at. One has
a bad plug, the screen lights but no video.
The other one works on an IBM PC, but it has a green screen.
When I get back out in the garage I will have another look.
Regards
Charlie Fox
>--
Charles E. Fox Video Productions
793 Argyle Rd.
Windsor Ontario N8Y3J8
519-254-4991
www.chasfoxvideo.com
I am drowning here. If anyone wants it you can pickup free in Burlington,
VT. Unfortunately I'm very much not retired and simply don't have the
time to deal with shipping.
There are probaby 2-3 large storage bins of boxed product, docs without
software and software without docs - and, gasp, software WITH docs!
There's a limit to how much one can accumulate and I think I'm past it
:-). For extra credit: I can probably arrange to hand over a fair amount
of miscellaneous junk, err, classic stuff if you have the room to take it.
Take advantage of this special offer before the snow flies!
Steve
--
Goodwill Industries rehabs computers and sells computer parts, at
least in Austin, Texas. The Goodwill Computer Museum is a natural
outgrowth of that effort. In this video, museum curator Lisa Worley
takes Slashdot's Timothy Lord on a tour of the museum. Remember that
TRS-80 you threw away in 1982? Well, they saved several of them to
stimulate your nostalgia-based pleasure nodules. Ditto many other
devices both common and rare, including a pre-Dell computer made and
signed by Texas computer celebrity Michael Dell. So sit back and enjoy
the ride, as Timothy does the walking and Lisa does the talking, kind
of like Night at the Museum -- but without CGI dinosaurs and other
life forms getting between you and the classic computers.
http://hardware.slashdot.org/story/13/10/29/1823212/welcome-to-the-goodwill…
--
Liam Proven ? Profile: http://lproven.livejournal.com/profile
Email: lproven at cix.co.uk ? GMail/G+/Twitter/Flickr/Facebook: lproven
MSN: lproven at hotmail.com ? Skype/AIM/Yahoo/LinkedIn: liamproven
Tel: +44 20-8685-0498 ? Cell: +44 7939-087884
While reading the wikipedia article on the ILLIAC IV there's a curious
excerpt relating to the disk media:
"They also provided a Burroughs B6500 mainframe to act as a front-end
controller. Connected to the B6500 was a laser optical recording medium, a
write-once system that stored up to 1 Tbit on a plastic disk covered with
a thin metal film."
Anyone know what this device was?
Cheers;
- JP
Hampton, Iowa
