23 May
23 May
5:30 p.m.
I just bought Kryoflux last month to read some Venix disks.
https://webstore.kryoflux.com/catalog/ is a good place to start.
Once I got a working floppy, and understood the output of dtc, I've been
loving mine. I'd recommend buying a known good floppy drive of the
appropriate flavor if you don't already have one... Once I had a known good
one, I was able to rehab one of the spare ones I had... But it wasn't worth
the hassle...
Warner
On Tue, May 23, 2017 at 6:19 PM, jim stephens via cctalk <
cctalk at classiccmp.org> wrote:
Anyone know of where these can be had now days?
thanks
jim
11:30 p.m.
On 05/23/2017 05:31 PM, Andrew Harvey via cctalk wrote:
I don't think Indivudual Computers make the
catweasle any more. They never
released a 64bit Windows driver for it.
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Why would anyone want a Catweasel at this stage? Technology has moved
past that.
--Chuck
24 May
24 May
1:59 a.m.
On Wed, May 24, 2017 at 8:30 AM, Chuck Guzis via cctalk
<cctalk at classiccmp.org> wrote:
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Some of us just want a working solution. So, any links for hardware,
software and an assembly description?
A Kryoflux would work, but since the software they provide isn't open
source, I can't compile it to work on the platform I use.
--
Regards,
Torfinn Ingolfsen
6:57 a.m.
On Wed, May 24, 2017 at 2:59 AM, Torfinn Ingolfsen via cctech <
cctech at classiccmp.org> wrote:
On Wed, May 24, 2017 at 8:30 AM, Chuck Guzis via
cctalk
<cctalk at classiccmp.org> wrote:
I looked at snagging the protocol used for their dtc program. It doesn't
look hard...
But I have a mac, so I don't need worry, and it is a super easy solution to
archive disks. I doubt I could do better with dd given the variety of
diskettes I have.
Warner
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Some of us just want a working solution. So, any links for hardware,
software and an assembly description?
A Kryoflux would work, but since the software they provide isn't open
source, I can't compile it to work on the platform I use.
8:28 a.m.
On 05/24/2017 01:59 AM, Torfinn Ingolfsen via cctalk wrote:
On Wed, May 24, 2017 at 8:30 AM, Chuck Guzis via
cctalk
<cctalk at classiccmp.org> wrote:
Some of us just want a working solution. So, any links for hardware,
software and an assembly description?
Mine are for specific-purpose applications, so they're not likely to be
of use to anyone else. Note that I'm not interested in archiving disks,
but rather getting at their content and saving that.
But golly, it isn't that difficult--most MCUs have several timers, and a
"capture" facility so reading should be easy. Writing is again, mostly
feeding a PWM output to the drive. The floppy interface itself is very
much brain-dead.
This isn't news--the HxC emulator basically does the work and runs on an
STM32F1 platform--which is weak tea compared to the ARM CPUs currently
available.
My .02 cents.
Chuck
23 May
23 May
11:30 p.m.
On 05/23/2017 05:31 PM, Andrew Harvey via cctalk wrote:
I don't think Indivudual Computers make the
catweasle any more. They never
released a 64bit Windows driver for it.
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Why would anyone want a Catweasel at this stage? Technology has moved
past that.
--Chuck
24 May
24 May
11:19 a.m.
On 5/24/2017 12:30 AM, Chuck Guzis via cctalk wrote:
On 05/23/2017 05:31 PM, Andrew Harvey via cctalk
wrote:
But who wants to write the software?
I am building a 1977 ttl style computer because now I have spare time.
Finding vintage or similar devices is being a challenge as well fighting
modern OS to have even a C compiler and a TEXT editor.
Technology is not better, just cheaper.
I plan to use a low of LOW POWER 22V10's and undefined ALU logic
since I have several designs I want to play with. NOW is your last
chance to buy small quantities of things like 2901's and small TTL RAM's
and floppy disks.
Ben.
I don't think Indivudual Computers make the
catweasle any more. They never
released a 64bit Windows driver for it.
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Why would anyone want a Catweasel at this stage? Technology has moved
past that.
--Chuck
12:35 p.m.
On 05/24/2017 11:19 AM, ben via cctalk wrote:
But who wants to write the software?
Yes, just so. I learned about that one decades ago.
I am building a 1977 ttl style computer because now I
have spare time.
Finding vintage or similar devices is being a challenge as well fighting
modern OS to have even a C compiler and a TEXT editor.
Technology is not better, just cheaper
Modern technology is not only cheaper, but it's faster and uses less
power--and is usually more flexible.
I suspect that a PDP-11 in FPGA is quite a bit more reliable than the
real thing--and when you're done you have a nice abstract description of
the hardware in VHDL format.
And yes, I have a pile of old CMOS/ECL/TTL logic.
Remember when CMOS logic was new-- +15V Vdd and 1MHz top speed?
--Chuck
12:49 p.m.
On 5/24/17 3:35 PM, Chuck Guzis via cctalk wrote:
On 05/24/2017 11:19 AM, ben via cctalk wrote:
Its why I keep all my old machines. We have
an understanding, that is I
understand them fully, hardware and software.
Oddly the assumption is 16 bit, PDP-11, why not DG Nova, TI990.
Could easily be 8 bit, 12bit, 18 bit as well.
But who wants to write the software?
Yes,
just so. I learned about that one decades ago.
I am building a 1977 ttl style computer because
now I have spare time.
Finding vintage or similar devices is being a challenge as well fighting
modern OS to have even a C compiler and a TEXT editor.
Technology is not better, just cheaper
Modern technology is not only cheaper, but
it's faster and uses less
power--and is usually more flexible. I suspect that a PDP-11 in FPGA is quite a bit more
reliable than the
real thing--and when you're done you have a nice abstract description of
the hardware in VHDL format.
And yes, I have a pile of old CMOS/ECL/TTL logic.
And Germanium transistors...
Remember when CMOS logic was new-- +15V Vdd and 1MHz
top speed?
--Chuck
I remember when RTL was new and uRTL was a later improvement.
Allison
25 May
25 May
3:03 a.m.
On 05/25/2017 12:18 AM, Chuck Guzis via cctalk wrote:
On 05/24/2017 12:49 PM, allison via cctalk wrote:
Both and 3 input nors in a flat pack.... about 5000 of
them were used in
AGC.
Allison
I remember when RTL was new and uRTL was a later
improvement.
Flatpack and TO-100. I probably still have a few mW RTL packages
around. DIPs came later. --Chuck
8:34 a.m.
On May 25, 2017, at 6:03 AM, allison via cctalk
<cctalk at classiccmp.org> wrote:
On 05/25/2017 12:18 AM, Chuck Guzis via cctalk wrote:
Early RTL from Fairchild came in round transistor cans (TO-8?) with 8 leads. Dual 2-input
NOR (914), single JK flop (923), dual (?) inverters (900) if I remember right. Never used
them, but I remember seeing them in a Morse code keyboard article around 1968.
paul
On 05/24/2017 12:49 PM, allison via cctalk
wrote:
Both and 3 input nors in a flat pack.... about 5000 of
them were used in
AGC. I remember when RTL was new and uRTL was a later
improvement.
Flatpack and TO-100. I probably still have a few mW RTL packages
around. DIPs came later.
12:51 p.m.
On May 24, 2017, at 3:35 PM, Chuck Guzis via cctalk
<cctalk at classiccmp.org> wrote:
I suspect that a PDP-11 in FPGA is quite a bit more reliable than the
real thing--and when you're done you have a nice abstract description of
the hardware in VHDL format.
The trick is to get it close enough to correct, given the documentation lapses. The
PDP-11 is better off than many other machines (VAX and Alpha are better still) because it
has an architecture manual, but even that is not 100% complete.
http://pdp2011.sytse.net/wordpress/pdp-11/ is a nice example of an FPGA PDP-11 (actually,
the whole family -- conditional compile the model you want). It seems pretty accurate;
the fact that it runs RSTS is a good sign since that tends to be about as picky as any
PDP-11 software you'll find.
And yes, I have a pile of old CMOS/ECL/TTL logic.
Remember when CMOS logic was new-- +15V Vdd and 1MHz top speed?
No, but I remember CD4000 series logic: Vdd anywhere between 3 and 18 volts -- crank up
the voltage if you want it to go faster ("less slow").
paul
12:58 p.m.
On 5/24/2017 1:35 PM, Chuck Guzis via cctalk wrote:
On 05/24/2017 11:19 AM, ben via cctalk wrote:
I am not to sure about that.
If a schematic has a bug you can use a logic probe to find the error.
With typo in VHDL you have hard problem finding that single gate
error.
But who wants to write the software?
Yes, just so. I learned about that one decades ago.
I am building a 1977 ttl style computer because
now I have spare time.
Finding vintage or similar devices is being a challenge as well fighting
modern OS to have even a C compiler and a TEXT editor.
Technology is not better, just cheaper
Modern technology is not only cheaper, but it's faster and uses less
power--and is usually more flexible.
I suspect that a PDP-11 in FPGA is quite a bit more reliable than the
real thing--and when you're done you have a nice abstract description of
the hardware in VHDL format. And yes, I have a pile of old CMOS/ECL/TTL logic.
Remember when CMOS logic was new-- +15V Vdd and 1MHz top speed?
This is Canada. RADIO SHACK was your only place to get anything.
99 cents for 7400.
Ben.
2:28 p.m.
On 5/24/17 12:58 PM, ben via cctalk wrote:
With typo in VHDL you have hard problem finding that
single gate
error.
The world has been debugging 100,000+ gate systems with simulations for
a few decades now.
Once you've built up a set of test vectors, it actually becomes really
obvious where a single gate error is through simulation.
3:16 p.m.
On 5/24/2017 3:28 PM, Al Kossow via cctalk wrote:
On 5/24/17 12:58 PM, ben via cctalk wrote:
Well I am NOT the world... GOD perhaps.
I know that I make typos and mistakes. More KISS with the design I
am working on all the better. The first version will have NO IRQ's
just to keep the random logic design simple. And just for a change
it will be a 9 bit cpu, with a mini- front panel.
Still fits in 1970's era with logic dropped in price, but memory
still expensive.
Ben.
With typo in VHDL you have hard problem finding
that single gate
error.
The world has been debugging 100,000+ gate systems with simulations for
a few decades now.
Once you've built up a set of test vectors, it actually becomes really
obvious where a single gate error is through simulation.
3:29 p.m.
Al Kossow wrote on: Wed, 24 May 2017 14:28:19 -0700
On 5/24/17 12:58 PM, ben via cctalk wrote:
In addition, a tool like the Altera Signal probe allows you to bring any
signal you want to a pin you select so you can use an oscilloscope or
logic analizer to look at it if that is how you are more comfortable
debugging hardware. Another option is to include a whole logic analyzer
inside your design, like the Xilinx ChipScope or Altera SignalTap II.
That talks to software running on your PC and has all the functionality
of a real logic analyzer.
I have not used these tools myself but instead did the equivalent the
hard way: I patched the VHDL code to bring the signal I wanted to look
at to the pin I was probing with my oscilloscope. That was a bit awkward
when the signal was several levels down in the design.
My point is that though Al is right that it is better to debug with a
simulator, those of us who prefer to look at the real thing lose nothing
with FPGAs. In fact, given how hard it can be to attatch 60 little
probes to pins which are very close together we actually gain something.
By the way, in my scheme I actually had a case where it was hard to
debug because the FPGA worked one way when I touched it with the
oscilloscope probe and did something different when I didn't.
-- Jecel
With typo in VHDL you have hard problem finding
that single gate
error.
The world has been debugging 100,000+ gate systems with simulations for
a few decades now.
Once you've built up a set of test vectors, it actually becomes really
obvious where a single gate error is through simulation.
9:27 p.m.
On 05/24/2017 02:28 PM, Al Kossow via cctalk wrote:
Once you've built up a set of test vectors, it
actually becomes really
obvious where a single gate error is through simulation.
Does anyone collect the old Zycad hardware emulators? They were the
(very expensive) cat's whiskers at one time.
--Chuck
25 May
25 May
8:35 a.m.
On 05/24/2017 02:58 PM, ben via cctalk wrote:
I am not to sure about that.
If a schematic has a bug you can use a logic probe to find
the error.
With typo in VHDL you have hard problem finding that
single gate
error.
With Xilinx, they have a VERY good simulator. You create a
"test bench" in VHDL or other HDL to describe external
signals. Then, you can probe around like a logic analyzer,
looking at internal signals behavior, making sure all the
counters are in the right state, and logic is responding to
external events, etc. If that doesn't make it all work
right, they have ChipScope, which builds a logic analyzer in
available remaining available hardware on the FPGA, and you
access it from JTAG. You compile into your FPGA the points
you need to see, and then get very similar traces to the
sim, but it is viewing the signals embedded into the actual
hardware of whatever you are working on. If you didn't set
it up to see the right signals, you change what is included
in ChipScope and re-synthesize. It isn't quite as
convenient as the sim, but it will allow you to figure out
if some small section of your FPGA is not functioning right
within a larger system.
With VHDL, you generally do NOT work at the gate level.
Jon
8:39 a.m.
On May 25, 2017, at 11:35 AM, Jon Elson via cctalk
<cctalk at classiccmp.org> wrote:
On 05/24/2017 02:58 PM, ben via cctalk wrote:
You can do the same with other VHDL processors. If you don't want to deal with a
particular manufacturer and potentially pay major money for the tool set, there's
GHDL, a open source GCC-based VHDL modeler. It has some handy capabilities, such as a way
to hook C functions into the model.
paul
I am not to sure about that.
If a schematic has a bug you can use a logic probe to find the error.
With typo in VHDL you have hard problem finding that single gate
error.
With Xilinx, they have a VERY good simulator. You create a "test
bench" in VHDL or other HDL to describe external signals.
9:14 a.m.
On 5/25/2017 9:39 AM, Paul Koning wrote:
I use the other BRANDS. I never liked VHDL because I can never figure
how the logic port mapping works and the on edge logic.
Also what is wrong with custom designs IN ADL,PAL and WINCUPL. Your FPGA
logic is so custom you have no good portable logic for ram or rom on
chip any how.
Ben.
simulating ttl computer with software.
Simulating ttl with 22v10's.
Simulating 22v10's with FPGA.
easy design and testing.
On May 25, 2017, at 11:35 AM, Jon Elson via
cctalk <cctalk at classiccmp.org> wrote:
On 05/24/2017 02:58 PM, ben via cctalk wrote:
You can do the same with other VHDL processors. If you don't want to deal with a
particular manufacturer and potentially pay major money for the tool set, there's
GHDL, a open source GCC-based VHDL modeler. It has some handy capabilities, such as a way
to hook C functions into the model.
paul
I am not to sure about that.
If a schematic has a bug you can use a logic probe to find the error.
With typo in VHDL you have hard problem finding that single gate
error.
With Xilinx, they have a VERY good simulator. You create a "test bench"
in VHDL or other HDL to describe external signals.
9:39 a.m.
On May 25, 2017, at 12:14 PM, ben <bfranchuk at
jetnet.ab.ca> wrote:
On 5/25/2017 9:39 AM, Paul Koning wrote:
You can do the same with other VHDL processors. If you don't want to deal with a
particular manufacturer and potentially pay major money for the tool set, there's
GHDL, a open source GCC-based VHDL modeler. It has some handy capabilities, such as a way
to hook C functions into the model.
paul
I use the other BRANDS. I never liked VHDL because I can never figure how the logic port
mapping works and the on edge logic.
Also what is wrong with custom designs IN ADL,PAL and WINCUPL. Your FPGA
logic is so custom you have no good portable logic for ram or rom on chip any how.
That remains to be seen. I'm doing a very large model on GHDL right now. Eventually
it will move to an FPGA. At that point, a few small details, like the inner bits of the
memory model, will be device dependent. Right now in that spot I use an interface taken,
more or less, from a Xilinx app note. But that's only a few hundred lines out of
about 200k lines.
As for custom languages, I've used ABEL (from Lattice). It was ok for a bit of logic
amounting to a few dozen gates, but I'm glad I'll never have to go back to it.
There is of course Verilog as another option. I use VHDL because that's what I
learned first and because I found GHDL. There's a nice opportunity for language wars
here which I'll decline.
paul
24 May
24 May
3 p.m.
New subject: DIY Kryoflux or Catweasle
> But who wants to write the software?
On Wed,
24 May 2017, Chuck Guzis via cctalk wrote:
Yes, just so. I learned about that one decades ago.
It just needs to be open source software, open source hardware, also
available assembled, optionally bundled with or mounted in floppy drives
for 3.5" 5.25", 8".
It should sell for less than $20 (with 3.5" drive, slightly higher with
8", even higher with multi-drive 3",3.25",3.5",5.25",8" in a
single
cabinet)
Support should be live 24/7.
The software needs to function under DOS, Windoze, Linux, Mac, Android.
The software needs to provide raw flux transitions, along with
firmware to be compatible and work with CatWeasel, Kryoflux, Option Board
software.
It should have imaging software, both flux transition and IMD
compatability.
It needs to provide disk, track, sector data.
It needs to include complete emulation of WD-179x, and NEC-765
controllers. The NEC emulation should provide optional going blind after
index, as well as multiple variations of how it handles 128 byte sectore.
WD-179x support should also add WD-1771 address mark support (TRS80)
It should have windows drivers that permit it to be the floppy system.
It should be able to duplicate ANY disk, including all copy-protection
schemes. (supply a paper-clip for making scratch for pro-lock)
It should have "Installable File System" support sufficient to be able to
mount 2500 different floppy disk formats.
Sufficient buffer to read data from disk in one format, reformat the disk
in another format, and write the data back to it.
Its software should identify and report the disk format of the disk in the
drive.
Optional scan and repair of file-system and sector errors, including
"refresh format" (read data from track, reformat track, write data back
out)
Multi-language spell-chequer?
Alignment exerciser, plus software for DDD in ROM.
Built-in SD slot for storing content of disks.
support for disk changer and high speed copying
Interface should include USB (micro-USB for Android), RS232,
Centronics-style parallel, 20-mA, . . .
Should it include emulation and drive support for ST412/506? ESDI? SCSI?
But, we're probably not including some essential capability.
Whatever features it has, SOMEBODY will say that it is INSANE to have
bothered with some of those features, but not to have included some other
feature that they want.
3:02 p.m.
New subject: DIY Kryoflux or Catweasle
It just needs to be open source software, open source
hardware, also
available assembled, optionally bundled with or mounted in floppy
drives for 3.5" 5.25", 8".
It should sell for less than $20 (with 3.5" drive, slightly higher with
8", even higher with multi-drive 3",3.25",3.5",5.25",8" in
a single
cabinet)
Support should be live 24/7.
Fred,
You had me at 24/7. Put me down for two!
;)
-Ali
3:22 p.m.
New subject: DIY Kryoflux or Catweasle
But, we're probably not including some essential
capability.
Whatever features it has, SOMEBODY will say that it is INSANE to have
bothered with some of those features, but not to have included some
other feature that they want.
Instructions in Chinese,Japanese,and Basic English in blue on a tiny sheet
of rice paper.
3:52 p.m.
New subject: DIY Kryoflux or Catweasle
> But, we're probably not including some
essential capability.
> Whatever features it has, SOMEBODY will say that it is INSANE to have
> bothered with some of those features, but not to have included some
> other feature that they want.
On Wed, 24 May 2017, ben via cctalk wrote:
Instructions in Chinese,Japanese,and Basic English in
blue on a tiny sheet
of rice paper.
. . . and leave off the other languages?
You don't dare include Amharic if you don't have Oromo, etc.
SO, no written instructions. All instructions will be silent,
uncaptioned videos.
(available on 1/2" Sony CV series reel to reel B&W videotape,
convertable to 1" Ampex type C by special order)
I wonder if the market is still flooded with BBC "Doctor Who" 2"
videotapes for erasing and re-use?
10:22 p.m.
New subject: DIY Kryoflux or Catweasle
On 5/24/2017 4:52 PM, Fred Cisin via cctalk wrote:
Well if you have any BBC DR WHO tapes, there are several gaps
in the surviving recordings that need filling in.
Ben.
> But,
we're probably not including some essential capability.
> Whatever features it has, SOMEBODY will say that it is INSANE to have
> bothered with some of those features, but not to have included some
> other feature that they want.
On Wed, 24 May 2017, ben via cctalk wrote:
Instructions in Chinese,Japanese,and Basic
English in blue on a tiny
sheet
of rice paper.
. . . and leave off the other languages?
You don't dare include Amharic if you don't have Oromo, etc.
SO, no written instructions. All instructions will be silent,
uncaptioned videos.
(available on 1/2" Sony CV series reel to reel B&W videotape,
convertable to 1" Ampex type C by special order)
I wonder if the market is still flooded with BBC "Doctor Who" 2"
videotapes for erasing and re-use?
25 May
25 May
10:33 a.m.
New subject: OT: BBC videotapes (Was: DIY Kryoflux or Catweasle
> I wonder if the market is still flooded with BBC
"Doctor Who" 2"
> videotapes for erasing and re-use?
On Wed, 24 May 2017, ben via cctalk wrote:
Well if you have any BBC DR WHO tapes, there are
several gaps
in the surviving recordings that need filling in.
For any unfamiliar with the reference, . . .
from 1967 to 1978, BBC routinely erased and reused the
tapes of shows,
including "Doctor Who".
And, occasionally would dumpster film copies to free up shelf space.
Some of that was an assumption that there was no further value or use in
retaining copies, since nobody would be interested in reruns, along with
cost of paying royalties for any re-broadcast (Equity contract was
draconian);
some was cost and value of blank tape;
and much was assumptions that "some other department" maintained archival
copies.
In 1978, executives were finally convinced that due to the advent of home
videotape, that there might be future value, and there was a policy change
to stop disposing of them.
152 episodes, mostly from the 1960s, were missing.
Efforts have been made to locate missing episodes. That includes
retrieving copies sent overseas, buying some from personal collections,
finds in storage sheds in the outback, even gathering home audio tapes and
amateur 8mm and Super-8 "kinetoscope" (movie camera aimed at TV screen).
Copies that had been transcoded from PAL to NTSC or SECAM have now been
transcoded back.
BBC had "professionally" done some kinetoscope copies. Those were
16mm B&W, and BBC colorised some of those, including some commercial
colorisation services.
But contrary to common knowledge that when making B&W films, better
image quality results from using a B&W monitor, the BBC kinetoscope had
had a color monitor.
Fortuitously, the B&W film was sharp enough to be able to make out the dot
mask of the CRT! That made possible the development of a new technique -
computer recognition of which pixels were the original RGB dots of the
image! That, unlike manual colorisation, results in reasonably exact
recreation of the original colors.
Some of the missing content has even been replaced with animation,
synched to home audio. Earlier this year, BBC released animated
version of "Power Of The Daleks"
97 of the 253 episodes from the first six years are still unavailable.
Almost all of the content that they have was released first as VHS, and
now on DVD. The DVDs all have SDH (Subtitles for Deaf/Hard-of-hearing)
available. To complete my collection of the released ones, I had to buy
quite a few through ebay.co.uk . ANYDVD and Handbrake worked
surprisingly smoothly.
So, yes, if I had any of those 2" videotapes, 16mm films, or even off-air
tapes of missing episodes, I would contact BBC.
--
Grumpy Ol' Fred cisin at xenosoft.com
26 May
26 May
11:17 a.m.
New subject: OT: BBC videotapes (Was: DIY Kryoflux or Catweasle
On Thu, May 25, 2017 at 10:33:41AM -0700, Fred Cisin via cctalk wrote:
[...]
Fortuitously, the B&W film was sharp enough to be
able to make out the dot
mask of the CRT! That made possible the development of a new technique -
computer recognition of which pixels were the original RGB dots of the image!
That, unlike manual colorisation, results in reasonably exact recreation of
the original colors.
I don't know if you're describing yet another way colour was retrieved from
telecine recordings, or a faulty recollection of the detail of James Insell's
work at BBC R&D.
James's moment of inspiration was when he was watching some old Doctor Who
telerecordings that had been telecined back and had caused what appeared to be
artifact colour. He realised that the film recording contained enough detail to
capture the colour subcarrier.
The bit that was combined genius and perspiration was figuring out the phase of
the colour signal, since the colour burst never made it into the recording.
Without that, one can't reliably separate U from V and the hue will be
essentially random.
12:30 p.m.
New subject: OT: BBC videotapes (Was: DIY Kryoflux or Catweasle
> Fortuitously, the B&W film was sharp enough to
be able to make out the dot
> mask of the CRT! That made possible the development of a new technique -
> computer recognition of which pixels were the original RGB dots of the image!
> That, unlike manual colorisation, results in reasonably exact recreation of
> the original colors.
On Fri, 26 May 2017, Peter Corlett wrote:
I don't know if you're describing yet another
way colour was retrieved from
telecine recordings,
possibly
or a faulty recollection of the detail of James
Insell's
work at BBC R&D.
much more likely.
Thank you.
My information is fourth hand, from something discussed on a TV talk show.
(typical unreliable source!)
James's moment of inspiration was when he was
watching some old Doctor Who
telerecordings that had been telecined back and had caused what appeared to be
artifact colour. He realised that the film recording contained enough detail to
capture the colour subcarrier.
The bit that was combined genius and perspiration was figuring out the phase of
the colour signal, since the colour burst never made it into the recording.
Without that, one can't reliably separate U from V and the hue will be
essentially random.
http://icolorist.com/dr-who-restoration-by-enthusiasts/
http://www.techmind.org/colrec/
Have some discussion of details.
We should be grateful that they developed those RE-colourisation
techniques and didn't stick with the USA ("Legend"?)
computer assisted manual Ted Turner style colorization.
--
Grumpy Ol' Fred cisin at xenosoft.com
12:49 p.m.
New subject: OT: BBC videotapes (Was: DIY Kryoflux or Catweasle
or a faulty recollection of the detail of James
Insell's
work at BBC R&D.
Here's Insell's 2007 description:
http://www.insell.co.uk/colourisation/Recovery_of_Colour_Information_0-2.htm
24 May
24 May
6:19 p.m.
On 05/24/2017 02:19 PM, ben via cctech wrote:
On 5/24/2017 12:30 AM, Chuck Guzis via cctalk wrote:
I have a load of all of those... 2901Cs the faster ones. The 2901 tends
to force
the flavor of the hardware and instructions toward microcoded machine.
If your doing your own design an interesting flavor is a TTA, Transport
Trigged Architecture
sometimes called a OIS (one instruction machine). For that the machine
has one instruction
I did a Move machine and the whole word is source, destination and
options like jump if zero.
Tends to be very unique, can be fast and fairly simple since the
instruction cycle is fetch, do,
and repeat. That can also be used as a microcode engine for a more
conventional machine.
When you build its hand to not dream.
Allison
On 05/23/2017 05:31 PM, Andrew Harvey via cctalk
wrote:
But who wants to write the software?
I am building a 1977 ttl style computer because now I have spare time.
Finding vintage or similar devices is being a challenge as well fighting
modern OS to have even a C compiler and a TEXT editor.
Technology is not better, just cheaper.
I plan to use a low of LOW POWER 22V10's and undefined ALU logic
since I have several designs I want to play with. NOW is your last
chance to buy small quantities of things like 2901's and small TTL RAM's
and floppy disks.
I don't think Indivudual Computers make the
catweasle any more. They
never
released a 64bit Windows driver for it.
In point of advancing technology, one can purchase a STM32F4 development
board with USB, UART, microSD, battery-backed RTC and oodles of timers
and I/Os as well as a TFT interface for less than $12 shipped. Almost
all I/Os are 5V tolerant--and can be configured as open-drain if
desired. 192KB of fast SRAM and a CPU running at about 168MHz.
Perfectly capable of doing sampling of floppy output.
Why would anyone want a Catweasel at this stage? Technology has moved
past that.
--Chuck Ben.
10:32 p.m.
On 5/24/2017 7:19 PM, allison via cctech wrote:
I have a load of all of those... 2901Cs the faster
ones. The 2901 tends
to force
the flavor of the hardware and instructions toward microcoded machine.
But if you want 9 or 18 bits, 2901 is not the answer.
A 74181 can be tricked in to being used as 3 bit alu.
When you build its hand to not dream.
Or over
design.
Allison
Ben.
10:53 p.m.
-----Original Message-----
From: cctech [mailto:cctech-bounces at classiccmp.org] On Behalf Of ben via cctech
Sent: Thursday, May 25, 2017 1:32 AM
To: cctech at classiccmp.org
Subject: Re: Kryoflux or Catweasle
On 5/24/2017 7:19 PM, allison via cctech wrote:
Can you tell more about the 3-bit trick?
-----
paul
I have a load of all of those... 2901Cs the
faster ones. The 2901 tends
to force
the flavor of the hardware and instructions toward microcoded machine.
But if you want 9 or 18 bits, 2901 is not the answer.
A 74181 can be tricked in to being used as 3 bit alu.
----
Ben.
2767
days inactive
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days old
36 comments
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participants (15)
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abuse＠cabal.org.uk -
aek＠bitsavers.org -
allisonportable＠gmail.com -
andrew＠cerberus-software.com.au -
bfranchuk＠jetnet.ab.ca -
cclist＠sydex.com -
cctalk＠ibm51xx.net -
cisin＠xenosoft.com -
elson＠pico-systems.com -
imp＠bsdimp.com -
jecel＠merlintec.com -
jwsmail＠jwsss.com -
paulkoning＠comcast.net -
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