25 Oct
2010
25 Oct
'10
10:54 a.m.
Hi guys,
I have -- just this second -- got the standalone, single-board
DiscFerret hardware ("0I06") to image a disc. First, the proof:
Scatter plot:
http://www.discferret.com/temp/dat.scatter.png
Histogram:
http://www.discferret.com/temp/dat.histogram.png
Raw transition data, gzipped space-separated format. First column is
array index, second column is the timing value:
http://www.discferret.com/temp/dat.gz
Rawbinary track dump, gzipped. Most significant bit of each byte is the
status of the INDEX sensor (1=index detected). If (x&0x7f) = 0, then a
counter carry occurred -- the next byte should have 128 added to it.
Repeated counter-carries are allowed.:
http://www.discferret.com/temp/dat.bin.gz
MagScan analyser output for dat.bin:
http://www.discferret.com/temp/dat.magscan.txt
For those of you who have a copy of the sources to my Magdecode decoder
engine (I know I sent it to at least one person on-list...), the
Rawbinary dump should load straight into Magdecode. The space-separated
data can be loaded straight into Gnuplot (which is what I used to
produce the plots), and I suspect MATLAB and Octave can probably load it
too.
The image file was created from an old coverdisc from "PC Zone"
magazine, and is completely undated on the label. The volume label is
"PCZ_OCT_3" which suggests it's from October, with last-modified dates
in February and August 1993. It only covers Track Zero, which (if memory
serves) is the MBR, FAT and Root Directory. The disc is 720K DOS format,
sampled at 40MHz.
Other things to note:
- The hardware works fine at 80MHz, and possibly faster than that. It
should be possible to sample with enough resolution to image a 5Mbps MFM
hard disc.
- There are plenty of spare registers. The new PIC uses 8-bit
multiplexed addressing, which gives 256 register addresses. Only 16 are
in use at the moment (!)
- Write support isn't enabled yet. I need to port this across from
DiscRW and test it (and no doubt rewrite parts of it, as I did with the
reader engine).
Surprisingly, there are only a few minor issues on the 0I06 PCBs:
- C6 is missing a polarity marker. This is a non-issue, as one end
connects to the ground plane and the other quite obviously connects to
+5V.
- Some of the component pads are rather small (notably the inductors
and Schottky diodes in the power supply). This makes it hard to heat
both the pad and the component pin at the same time, and thus makes the
parts a bit of a pig to solder. I worked around this with a hot-air gun,
preheater and solder paste... later boards will have bigger pads.
- The power supply chip is a QFN with pads under the chip. The only
way to solder it down is to use a hot-air gun... unfortunately TI don't
make this chip in a more accessible package, and the only viable
alternative would have nearly doubled the size of the power supply.
Despite these issues, it's perfectly possible to assemble a 0I06 and
have it work perfectly, without any "green-wire" fixes. I'm impressed:
usually a first-spin board needs at least one track-cut and a couple of
green-wires :)
Now here's where you guys come in.
I really don't want to have boxes and boxes of unused boards and parts
hanging around, so I need to know how many people would like to buy a
DiscFerret. These would be available as:
- PCB only
- PCB with the power supply section assembled and tested
- Fully assembled and tested PCB
- Some other form -- feel free to make suggestions!
I'd appreciate it if anyone interested in buying a DiscFerret could
email me at philpem at philpem.me.uk, with one of the following in the
subject line (start, end, on its own, uppercase, lowercase -- anything
will do, my procmail rule is pretty lenient):
- "I want a PCB on its own" -- DISCFERRETBARE
- "I want a PCB with the PSU built and tested" -- DISCFERRETPSU
- "I want the whole thing ready-built" -- DISCFERRETBUILT
- "I want a DiscFerret in some other form" -- DISCFERRETOTHER
Thanks to everyone who has supported the project thus far -- your
thoughts, ideas, comments and criticisms have been very useful!
Now to get my reflow oven working and build some prototypes... :)
Thanks!
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
25 Oct
25 Oct
10:49 a.m.
On Mon, 25 Oct 2010, Philip Pemberton wrote:
DiscFerret hardware ("0I06") to image a
disc. First, the proof:
Fantastic news Phil! Congrats!
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.simpits.org/geneb - The Me-109F/X Project
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://www.scarletdme.org - Get it _today_!
Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a turd
by the clean end.
2:06 p.m.
Philip Pemberton wrote:
Hi guys,
I have -- just this second -- got the standalone, single-board
DiscFerret hardware ("0I06") to image a disc.
Fantastic!
I really don't want to have boxes and boxes of
unused boards and parts
hanging around, so I need to know how many people would like to buy a
DiscFerret. These would be available as:
- PCB only
- PCB with the power supply section assembled and tested
- Fully assembled and tested PCB
- Some other form -- feel free to make suggestions!
Do you have some rough idea of costs? Or is that totally unknown until you
have an idea of interest?
(is "PCB along with any programmable parts supplied pre-programmed" a useful
option? Or do the boards contain enough smarts that you can easily
program/reprogram an assembled board using a plain ol' PC?)
cheers
Jules
3:39 p.m.
On Mon, 2010-10-25 at 16:06 -0500, Jules Richardson wrote:
Do you have some rough idea of costs? Or is that
totally unknown until you
have an idea of interest?
The smallest batch I can make up is three units, which costs as about
?95 per unit at "standard spec", without a power supply or case. With a
smaller FPGA, this can be knocked down to about ?90 per unit.
Note that the type of FPGA doesn't matter: the smaller part can be
specified as a Migration Device in Quartus, meaning the RBF file
(microcode) will work on both parts. The microcode currently uses about
1800 LEs, out of the 5000 available on the smallest part, and the 8000
on the larger part. I only used the 8000 LE part because I had some
lying around.
(is "PCB along with any programmable parts
supplied pre-programmed" a useful
option? Or do the boards contain enough smarts that you can easily
program/reprogram an assembled board using a plain ol' PC?)
Argh -- I forgot about that. You need to program the PIC with a
bootloader, then the board can take a firmware download over USB. You do
this with the In-Circuit Serial Programming port (the same port the
MPLAB Debuggers use to talk to the chip).
I'll probably get a batch of PICs made up with the bootloader
pre-loaded. A batch of 25 pre-programmed chips from MicrochipDirect
works out at about the same per-part as 25 blank chips from Farnell.
Adding a thermal-transfer label to the part only adds another 7p to the
per-chip cost... Hardly worth arguing about, really, and it saves
faffing around with a chip programmer.
I should note that there's a set of ICSP pads on the bottom-side of the
PCB. You can solder wire-wrap wire to these, then hook them up to an
ICD2, ICD3, PICKit2 or PICKit3 to debug the MCU firmware. There's a
similar feature for the FPGA -- a four-pin JTAG header and a pair of
power test points. This means you can wire the FPGA to an Altera
ByteBlaster2 or USB Blaster, run SignalTap and spy on the FPGA logic.
This has helped to resolve quite a few microcode bugs!
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
6:44 p.m.
New subject: What are these IBM 'thingys'
Are these early card reader parts and if so how early ?
http://cgi.ebay.com/2-Vintage-IBM-Large-Heavy-Switch-Thingys-/260683204959
6:51 p.m.
New subject: What are these IBM 'thingys'
My guess is that these are plug patch panels for a collator / sorter card reader or
printer.
My hint was the 'gold spikes'
Contacts for this patch panel
Randy
Date: Mon, 25 Oct 2010 18:44:49 -0700
From: leaknoil at gmail.com
To:
Subject: What are these IBM 'thingys'
Are these early card reader parts and if so how early ?
http://cgi.ebay.com/2-Vintage-IBM-Large-Heavy-Switch-Thingys-/260683204959
7:20 p.m.
New subject: What are these IBM 'thingys'
Pretty sure those are the connectors that went at the end of the (large)
cable that connected Unit Record equipment together; for instance connected
a Reproducing Punch to the Accounting Machine... The massive steel fixture
locked the socket and plug together. The cables I remember were about 1.5"
in diameter and fabric covered.
Ok, thats my best guess anyway.
bob.
On Oct 25, 2010 8:51pm, Randy Dawson <rdawson16 at hotmail.com> wrote:
My guess is that these are plug patch panels for a
collator / sorter card
reader or printer.
My hint was the 'gold spikes'
Contacts for this patch panel
Randy
> Date: Mon, 25 Oct 2010 18:44:49 -0700
> From: leaknoil at gmail.com
> To:
> Subject: What are these IBM 'thingys'
>
> Are these early card reader parts and if so how
early ?
>
7:26 p.m.
New subject: What are these IBM 'thingys'
It looks to me like a punch card exactly fits in there and the contacts
are what read the holes in the card. If a contact is made there is a
hole. If not the spot is unpunched. Hard to imagine that as a cable
connector. I don't actually know though.
On 10/25/2010 7:20 PM, rollerton at gmail.com wrote:
Pretty sure those are the connectors that went at the
end of the
(large) cable that connected Unit Record equipment together; for
instance connected a Reproducing Punch to the Accounting Machine...
The massive steel fixture locked the socket and plug together. The
cables I remember were about 1.5" in diameter and fabric covered.
7:49 p.m.
New subject: What are these IBM 'thingys'
On 10/25/10 7:26 PM, leaknoil wrote:
It looks to me like a punch card exactly fits in there
and the contacts are what read the holes in the card.
nope
cards are read with 12 brushes
they appear to be the cover connectors for interconnecting cables
8:05 p.m.
New subject: What are these IBM 'thingys'
Ah got it. The connector thing didn't make sense until I thought about
it reversed. Makes sense now. The flanged side threw me.
On 10/25/2010 7:49 PM, Al Kossow wrote:
On 10/25/10 7:26 PM, leaknoil wrote:
It looks to me like a punch card exactly fits in
there and the
contacts are what read the holes in the card.
nope
cards are read with 12 brushes
they appear to be the cover connectors for interconnecting cables
7:28 p.m.
On 10/25/2010 01:54 PM, Philip Pemberton wrote:
Hi guys,
First and foremost: Congratulations!
- Some of the component pads are rather small
(notably the inductors
and Schottky diodes in the power supply). This makes it hard to heat
both the pad and the component pin at the same time, and thus makes the
parts a bit of a pig to solder. I worked around this with a hot-air gun,
preheater and solder paste... later boards will have bigger pads.
- The power supply chip is a QFN with pads under the chip. The only
way to solder it down is to use a hot-air gun... unfortunately TI don't
make this chip in a more accessible package, and the only viable
alternative would have nearly doubled the size of the power supply.
[[ assuming I didn't mis-read the statement, and I'm teaching your
grandmother to suck eggs... ;-) ]]
The only thing I might be able to contribute to this discussion (as I'm
barely figuring out basic PAL/GAL logic in WinCUPL right now) is:
Instead of a heat gun, have you tried a mini electric oven or what we
call in the US a "toaster oven?"
http://store.curiousinventor.com/guides/Surface_Mount_Soldering/Solder_Past…
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=59
http://www.seattlerobotics.org/encoder/200006/oven_art.htm
I pointed a co-worker towards these articles about a year ago when he
mentioned he had a JetDirect board that quit working and he thought it
was a "chip with no pins" that could be at fault; he followed the
directions, repaired the board and it's been working fine to this day,
he's repaired a few other items (including an XBox360) in this manner as
well.
I will say that I have not tried it (yet) as I'm just getting further
into my hobbies after about 5 years; I'm down to one job instead of 3...
Hope this helps!
Roger "Merch" Merchberger
26 Oct
26 Oct
12:53 a.m.
On Mon, 2010-10-25 at 22:28 -0400, Roger Merchberger wrote:
The only thing I might be able to contribute to this
discussion (as I'm
barely figuring out basic PAL/GAL logic in WinCUPL right now) is:
Ooo, WinCupl is fun. That's where I started out, too -- programming GALs
with Atmel-Wincupl and a GALBlast.
Instead of a heat gun, have you tried a mini electric
oven or what we
call in the US a "toaster oven?"
I've got one -- I just need to bolt on a decent temperature controller.
The bimetal thermostat that it came with is a piece of junk which bases
its estimate of the oven temperature on the temperature of the front
metal panel... which means that it pretty much always runs flat-out.
Heh. Kenneth Maxon's article is what made me want to try toaster-oven
reflow :)
I will say that I have not tried it (yet) as I'm
just getting further
into my hobbies after about 5 years; I'm down to one job instead of 3...
Ugh... I've ended up doing "odd jobs" for people to cover the costs of
building the DiscFerret. My entire savings are basically gone, as is my
testgear budget (I was saving up for a spectrum analyser -- emphasis:
"was").
Ah well, it's been a wild (and somewhat fun) ride, at least.
--
Phil.
philpem at philpem.me.uk
http://www.philpem.me.uk/
30 Oct
30 Oct
2:18 a.m.
On 29/10/10 21:04, Al Kossow wrote:
On 10/25/10 10:54 AM, Philip Pemberton wrote:
No -- I haven't got that part finished yet!
The "adapter kit" won't be too expensive though -- it consists of a few
differential line drivers, a PCB and a couple of cables.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
I'd appreciate it if anyone interested in
buying a DiscFerret could
email me at philpem at philpem.me.uk
Would this version have connectors for ST-506 drives as well?
9:26 a.m.
On 10/30/10 2:18 AM, Philip Pemberton wrote:
On 29/10/10 21:04, Al Kossow wrote:
If it's going to be an adapter, could you add holes for SA1000-style 8" drives
(50pin/20pin cabling)?
On 10/25/10 10:54 AM, Philip Pemberton wrote:
No -- I haven't got that part finished yet!
The "adapter kit" won't be too expensive though -- it consists of a few
differential line drivers, a PCB and a couple of cables.
I'd appreciate it if anyone interested in
buying a DiscFerret could
email me at philpem at philpem.me.uk
Would this version have connectors for ST-506 drives as well?
11:35 a.m.
On 30/10/10 17:26, Al Kossow wrote:
If it's going to be an adapter, could you add
holes for SA1000-style 8"
drives (50pin/20pin cabling)?
I almost mistook that for a floppy drive until I looked it up on
Bitsavers...!
I can't see any real reason why SA1000 support couldn't be added to the
bridge-board. Looks like the only changes required would be:
- An oscillator to generate the 3.6866us +/- 0.1% timing clock
(270982 to 271524Hz, nominal 271253Hz). Although I have no idea what
standard crystal frequencies could be used to generate that signal. The
FPGA's PLL might be persuaded to do it, though, I'll have to check.
- Two jumpers to disconnect the Timing Clock from the ST412/506 Data
connector when these are not in use (or maybe just a second connector?)
- A 50-pin connector for the SA1000 control cable
The extra cost probably isn't worth worrying about... though I might
have to restrict drive selection to Drive 0 only in order to get enough
I/O pins for head selection.
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
12:29 p.m.
On 10/30/10 2:35 PM, Philip Pemberton wrote:
I can't see any real reason why SA1000 support
couldn't be added to the
bridge-board. Looks like the only changes required would be:
- An oscillator to generate the 3.6866us +/- 0.1% timing clock (270982
to 271524Hz, nominal 271253Hz). Although I have no idea what standard
crystal frequencies could be used to generate that signal. The FPGA's
PLL might be persuaded to do it, though, I'll have to check.
You could stick a little AD9833 (or similar) DDS chip on there. It's
overkill, but they're pretty cheap now, and you'll get the desired
frequency spot-on.
-Dave
--
Dave McGuire
Port Charlotte, FL
12:58 p.m.
On 30/10/10 20:29, Dave McGuire wrote:
You could stick a little AD9833 (or similar) DDS chip
on there. It's
overkill, but they're pretty cheap now, and you'll get the desired
frequency spot-on.
?8.25 each with no quantity discount is *not* cheap. The FPGA only costs
a few quid more than that.
Digikey have them for ?5.86, but that's still more than a crystal. I
wonder how the host adapters for the SA1000s generated this clock
frequency... it does seem somewhat odd.
The other thing is, I'd be concerned about releasing hardware with
SA1000 support without testing it on an actual drive. I'm willing to bet
the chances of me finding a working SA1000 in 230V/50Hz configuration
are somewhere between 'slim' and 'nil'.
I'll guarantee ST506 support though, given that I've got an ST277R RLL
drive and controller here. Just need an MFM controller for it, or the
RLL code tables for the Seagate ST21R or ST22R controller (which IIRC
uses an Adaptec AIC010 chip)...
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
1:39 p.m.
On 30 Oct 2010 at 15:29, Dave McGuire wrote:
On 10/30/10 2:35 PM, Philip Pemberton wrote:
Also, aren't the read/write data signals on the SA1000 differential?
Or do I have them confused with the ST506 interface?
--Chuck
I can't see any real reason why SA1000
support couldn't be added to
the bridge-board. Looks like the only changes required would be: -
An oscillator to generate the 3.6866us +/- 0.1% timing clock (270982
to 271524Hz, nominal 271253Hz). Although I have no idea what
standard crystal frequencies could be used to generate that signal.
The FPGA's PLL might be persuaded to do it, though, I'll have to
check.
You could stick a little AD9833 (or similar) DDS chip on there.
It's
overkill, but they're pretty cheap now, and you'll get the desired
frequency spot-on.
1:58 p.m.
On 30/10/10 21:39, Chuck Guzis wrote:
Also, aren't the read/write data signals on the
SA1000 differential?
Or do I have them confused with the ST506 interface?
They're both differential. It's just that the SA1000 expects you to feed
it a reference clock signal. It doesn't have to be locked against
write-data, it just has to be there, and be accurate to 0.1%...
Assuming the OEM manual is accurate, of course.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
31 Oct
31 Oct
7:06 p.m.
New subject: 8" winchester drive clock rates (was Re: DiscFerret: First working hardware, firmware and microcode!)
On 10/30/10 1:58 PM, Philip Pemberton wrote:
They're both differential. It's just that the
SA1000 expects you to feed it a reference clock signal. It doesn't have to be locked
against write-data, it just has to be there, and be accurate to 0.1%...
Assuming the OEM manual is accurate, of course.
It's used for the head stepping circuit on the SA1000 (schems in the svc manual)
I'm trying to figure out what the SA4000 expects. It seems to be a 140ns clock.
The main thing I need this for is recovering some PERQ data.
Just found the 4000 service manual, will have that on bitsavers soon.
Looking at the schematics, the Quantum 2000 series doesn't use it at all. Most of
my Xerox 8010 drives are from Quantum
I don't seem to have any docs for the Micropolis 8" drives.
7:45 p.m.
New subject: 8" winchester drive clock rates (was Re: DiscFerret: First working hardware, firmware and microcode!)
On 31 Oct 2010 at 19:06, Al Kossow wrote:
I'm trying to figure out what the SA4000 expects.
It seems to be a
140ns clock. The main thing I need this for is recovering some PERQ
data. Just found the 4000 service manual, will have that on bitsavers
soon.
If you need a check, I've got a working SA4008 with controller set up
here. It'll take a little digging with a long-shaft Torx driver to
get into it, so give me a little warning.
--Chuck
1 Nov
1 Nov
1:10 p.m.
New subject: 8" winchester drive clock rates (was Re: DiscFerret: First working
I'm trying to figure out what the SA4000 expects.
It seems to be a 140ns clock.
The main thing I need this for is recovering some PERQ data.
Just found the 4000 service manual, will have that on bitsavers soon.
I am assuming this is a real SA4000 from a PERQ 1 or 1a. That is, a 14"
winchester drive.
It doens't need a clock _input_ at all for reading. There is a
differential pair 'PLO clock' which are outputs from the drive and
consist of the sepeatated clock from the data separator on the drive. The
Write Clock pair are inputs, but are only needed for writing (which I
assume you are not goign to do). In fact the PERQ just links the PLO
clock outputs back to the write clock inputs by traces on the controller
board.
I asusme you have the schematics of the PERQ CIO board, etc.
One thing to watch for on a real SA4000 is the seek control logic. You
can sent it step pulses for one track at a time and it works fine. You
can sent it a burst of step pulses _faster than a given rate_ and it will
buffer them and then move the heads the apporopraite number of cylinders/
But if yousend it a burst of pulses too slowly, it will miscount and the
heads wil lnot be where youexpect them
The Seek counter logic is horrible, put it this way, if anyone who'd been
workign for me had come up with that design they would have been off ot
the unemployment office...
Looking at the schematics, the Quantum 2000 series doesn't use it at all. Most of
my Xerox 8010 drives are from Quantum
I don't seem to have any docs for the Micropolis 8" drives.
I have some information (including schematics) for the Micropolis 1200
series that were used on the PERQ 2 T1 machines. If you're working with
onoe of those from a PERQ, note that there's an ICL-designed board on top
of it that converts the interface to something sort-of like an SA4000,
but with differnet control signals (the PERQ had a couple of ports to
drive the SA4000 control lines, these were used to talk to this
interface board, but the microcode used was different, so the signals are
not the same). Again I have schematics, etc.
-tony
9:16 a.m.
Hi,
On Sat, Oct 30, 2010 at 8:35 PM, Philip Pemberton
<classiccmp at philpem.me.uk>wrote:
On 30/10/10 17:26, Al Kossow wrote:
Does this imply that the DiscFerret will support 8 inch floppy drives?
(I'm hoping it does...)
--
Regards,
Torfinn Ingolfsen
If it's going to be an adapter, could you add
holes for SA1000-style 8"
drives (50pin/20pin cabling)?
I almost mistook that for a floppy drive until I looked it up on
Bitsavers...!
3 Nov
3 Nov
3:56 p.m.
On 01/11/10 16:16, Torfinn Ingolfsen wrote:
Does this imply that the DiscFerret will support 8
inch floppy drives?
(I'm hoping it does...)
Ho yus. The current support list includes:
* Amstrad 3-inch (if I ever figure out why I can write 3us-spaced
pulses and get nothing but garbage back from the drive)
* PC 3.5-inch DSDD, DSHD and DSED (yep, 2.88MB too, once I get the
IBM drive hooked up and my half-dozen DSED discs arrive)
* PC, BBC, etc. 5.25-inch, hard and soft sectored up to 255 sectors
* 8-inch, hard and soft sectored up to... you guessed it, 255 sectors
* SA1000, ST412, or ST506-interface Winchester hard drives (with
adapter board). So that'll be basically all the 20-year-old heavy iron
that doesn't have a DEC sticker on it :)
* (maybe) Nintendo Famicom Disc System -- if I ever get an FDS to
play with. Bridgeboard and mods needed if you want to write FDS discs,
and possibly new microcode too.
Initial software support should include anything that uses a uPD765 or
WD177x/WD179x style controller. Though if people start sending me images
of strange disc formats (*cough* AmigaDOS), I might just have to add
format support for those too :)
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
4:37 p.m.
On Wed, 3 Nov 2010, Philip Pemberton wrote:
Ho yus. The current support list includes:
* Amstrad 3-inch (if I ever figure out why I can write 3us-spaced
pulses and get nothing but garbage back from the drive)
There are 3 inch drives that will hook up to a PC. Formatting PC-DOS
"360K" on a disk and trying to read THAT would at least give you a known
content on the disk. In addition, Amdek sold 3" drive sub-systems for
Coco and Apple ][.
* PC 3.5-inch DSDD, DSHD and DSED (yep, 2.88MB too,
once I get the
IBM drive hooked up and my half-dozen DSED discs arrive)
3.25" and some 2.9" ("SA400 compatible") should also work without
serious
problems, although watch out for power connector!
* SA1000, ST412, or ST506-interface Winchester hard
drives (with
adapter board). So that'll be basically all the 20-year-old heavy iron
that doesn't have a DEC sticker on it :)
25 years, maybe.
20 years would have to include "RLL" and ESDI (RLL has same cabling as
ST412, but different encoding and data-rates? , ESDI cabling looks the
same but has signal differences)
Initial software support should include anything that
uses a uPD765 or
WD177x/WD179x style controller. Though if people start sending me images
of strange disc formats (*cough* AmigaDOS), I might just have to add
format support for those too :)
You should already be able to handle most Amiga formats. Think MFM, but
without the IBM/WD style sector headers and structure.
Have you succeeded at FM yet?
MMFM?
GCR? (Mac (multiple data transfer rates), Apple 2 (13 and 16 sector),
Commodore, Victor/Sirius, Apple Lisa, etc.)
Tandy M100 Portable disk drive disks?
Whatever your final system can handle, somebody on this list can find
another, different format. And, sometimes arguments as to why it is
important enough to include :-)
--
Fred Cisin cisin at xenosoft.com
XenoSoft http://www.xenosoft.com
4:55 p.m.
On 11/3/10 4:37 PM, Fred Cisin wrote:
20 years would have to include "RLL" and
ESDI (RLL has same cabling as
ST412, but different encoding and data-rates? , ESDI cabling looks the
same but has signal differences)
Biggest difference is that the data separator is on the drive so you get NRZ
data back.
11:55 p.m.
Al wrote:
Biggest difference is that the data separator is on the drive so you
get NRZ
data back.
A possible problem with such drives (including ESDI, SMD, etc.) is that
the read gate from the controller to the drive needs to transition to
the active state at the right time (during a PLO sync field), or the
data separator may lock out-of-phase to the MFM data. In other words,
it may think that clock pulses are data pulses and vice versa. Whether
this happens depends a lot on the design of the drive electronics.
This makes it a pain to dump all the bits on a track at once, when you
don't have a priori knowledge of the track format,
because you can't just assert read gate continuously and get good NRZ
data from the drive.
Even when you get good data for one sector, the data separator can lose
sync at the write splice between that sector and the next ID field,
resulting in reading incorrect data for the following sector.
Eric
4 Nov
4 Nov
8:06 a.m.
On 11/3/10 11:55 PM, Eric Smith wrote:
This makes it a pain to dump all the bits on a track
at once, when you don't have a priori knowledge of the track format,
because you can't just assert read gate continuously and get good NRZ data from the
drive.
I ran into this about 10 years ago when I was trying to build a circuit to read data from
a Century Data Trident drive.
As Eric said, you can't just assert read gate continuously. At the time, I didn't
have the spec for the Trident interface
(very similar to SMD, it turns out) so I didn't know what the read gate timing was
supposed to look like.
You get very confusing logic analyzer traces if you continuously assert read gate :-(
It looks like there is almost enough circuitry (certainly enough FPGA real estate) in the
disc ferret to run it backwards
as an MFM disk simulator.
I/O pins count may be an issue.
11:35 a.m.
On 11/4/10 9:35 AM, Jules Richardson wrote:
Hey, don't give him a whole new market before
he's even dominated the first one! ;-)
I'm just happy someone has finally built this, after having been talked about for
years.
I just did another look around the web for USB 2.0 FPGA boards, and there still is very
few
that use Cyclone FPGAs. The nice thing about Philip's board is it has decent power
supplies.
It would have been nice to have a USB 2.0 interface. The Microchip part is cheap, though.
3 Nov
3 Nov
4:55 p.m.
On 3 Nov 2010 at 16:37, Fred Cisin wrote:
Doesn't SMD also fall within the 20 year boundary?
Drivetec/Kodak high-density drives?
The number of formats out there and the encoding thereof are quite
numerous. Just ask one of your friends with a Brother word processor
that uses 240K 3.5" floppies...
If you can accept Catweasel-type snapshots taken at 28MHz, I can
shove you a few of the more interesting ones.
--Chuck
* SA1000,
ST412, or ST506-interface Winchester hard drives (with
adapter board). So that'll be basically all the 20-year-old heavy
iron that doesn't have a DEC sticker on it :)
25 years, maybe.
20 years would have to include "RLL" and ESDI (RLL has same cabling
as ST412, but different encoding and data-rates? , ESDI cabling looks
the same but has signal differences)
7:12 p.m.
On 03/11/10 23:37, Fred Cisin wrote:
There are 3 inch drives that will hook up to a PC.
The Amstrad EME231 for one. Catch is, mine seems to be fried. If you
enable the write gate and leave WR_DATA high, then read the track,
RD_DATA stays high (as you might expect).
When actually writing to the disc (a 250ns pulse every 4us), I'm getting
garbage back -- random timing gaps between the pulses, from about 2us to
over 200us. The EME153 seems to be pulling the same trick (although
that's even more broken than the 231: the index sensor is stuck at "no
index mark")...
I just swapped the 3in drive for my 3.5in test drive (a Samsung SFD321,
cheap but it works) and an MF2DD disc I found in a desk drawer, and got
a perfect readback.
"Something's rotten in the state of Denmark..."
3.25" and some 2.9" ("SA400
compatible") should also work without serious
problems, although watch out for power connector!
Ya make one mistake and they never let you forget it...!
25 years, maybe.
20 years would have to include "RLL" and ESDI (RLL has same cabling as
ST412, but different encoding and data-rates? , ESDI cabling looks the
same but has signal differences)
Get me the RLL code tables and I'll make that work too :)
You should already be able to handle most Amiga
formats. Think MFM, but
without the IBM/WD style sector headers and structure.
... but I don't have any AmigaDOS samples to work from. I'd love to buy
an Amiga, but ?65 for an Amiga 600, or ?85 for a 1200? I'm not that
desperate.
Have you succeeded at FM yet?
Got a good read and a datasep lock, but the decoder isn't done yet.
MMFM?
No samples.
GCR? (Mac (multiple data transfer rates), Apple 2 (13
and 16 sector),
Commodore, Victor/Sirius, Apple Lisa, etc.)
See above -- need disc samples to do this. Although a 1541 and an X1541
cable would likely be enough to get the Commodore samples, and 1541s
aren't especially expensive (though from what I've heard they lack a
Track0 sensor, tend to bang the head out of alignment, and in true
Commodore fashion the PSUs tend to burn out in very short order).
Tandy M100 Portable disk drive disks?
No samples :(
Sounds interesting though. According to the COCI Wiki:
"Uses standard 720K 3.5" floppy disks; format is single side, 40
tracks, 2 sectors per track, 1280 bytes per sector. In short,
incompatible with just about everything."
<http://sliderule.mraiow.com/wiki/Tandy_Radio_Shack_TRS-80_Model_100/Tandy_Portable_Disk_Drive>
FM format, 1280 bytes per sector and two sectors per track.... fun.
Whatever your final system can handle, somebody on
this list can find
another, different format. And, sometimes arguments as to why it is
important enough to include :-)
If I can figure it out, I'll add it to the format specs. Seems a bit
pointless making an analyser that can only handle one or two formats.
What's amazing at this point is that I've added all these features, and
I'm still only using 8% of the logic capacity of the FPGA, and none of
the on-chip Block RAM (!)
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
7:28 p.m.
On 11/3/10 7:12 PM, Philip Pemberton wrote:
2,7 RLL is in the National application note
AN-0413_Disk_Interface_Design_Guide_and_Users_Manual_Jan86
page 6
What were you going to use for the differential receiver/driver? 5v or
3.3v part?
25 years,
maybe.
20 years would have to include "RLL" and ESDI (RLL has same cabling as
ST412, but different encoding and data-rates? , ESDI cabling looks the
same but has signal differences)
Get me the RLL code tables and I'll make that work too :)
7:39 p.m.
On 11/3/10 7:28 PM, Al Kossow wrote:
On 11/3/10 7:12 PM, Philip Pemberton wrote:
>> 25 years, maybe.
>> 20 years would have to include "RLL" and ESDI (RLL has same cabling as
>> ST412, but different encoding and data-rates? , ESDI cabling looks the
>> same but has signal differences)
>
National AN-500 has a reasonable description of ESDI
the actual ESDI spec is on bitsavers
http://bitsavers.org/pdf/cdc/discs/interface_specs/77738076-D2_ESDIspec.pdf
7:54 p.m.
an OK description of the SMS RLL decoder chip is under
http://bitsavers.org/pdf/sms/asic/OMTI_5027C_RLL_VCO_Encode_Decode_Dec86.pdf
4 Nov
4 Nov
10:28 a.m.
In article <4CD21CFE.2030309 at bitsavers.org>,
Al Kossow <aek at bitsavers.org> writes:
National AN-500 has a reasonable description of ESDI
the actual ESDI spec is on bitsavers
http://bitsavers.org/pdf/cdc/discs/interface_specs/77738076-D2_ESDIspec.pdf
I think this is the driver interface used on the Eve workstations
(successor to Lilith).
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
2:19 p.m.
On Wed, 3 Nov 2010, Philip Pemberton wrote:
Yes, most of them :-). More seriously, there are Hitachi 3" drives that
have a normal 34 pin edge connecotr (SA400-like pinouts) and powr
connector.
Ho yus. The current support list includes:
* Amstrad 3-inch (if I ever figure out why I can write 3us-spaced
pulses and get nothing but garbage back from the drive)
There are 3 inch drives that will hook up to a PC. Formatting PC-DOS "360K" on a disk and trying to read THAT
would at least give you a known
content on the disk. In addition, Amdek sold 3" drive sub-systems for
Coco and Apple ][.
I am sure I've seen them on a Beeb too...
* SA1000, ST412, or ST506-interface Winchester
hard drives (with
adapter board). So that'll be basically all the 20-year-old heavy iron
that doesn't have a DEC sticker on it :)
25 years, maybe. 20 years would have to include "RLL" and
ESDI (RLL has same cabling as
ST412, but different encoding and data-rates? , ESDI cabling looks the
Eh? RLL is a date encoding scheme, ST412 is a de-facto stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
Yes, you cna use RLL encoding on an ST412-type of drive. And one many
other tyeps of drive. The reason the PC crowd used to talk about MFM nd
RLL drives (meaning drive systems that used those encodings on a
ST412-type of interface) is that in general the encoding system only
matters to the user on a 'raw' interface, and the ST412 was the only
common raw interface used on PCs.
same but has signal differences)
It's very different... For one thing the data separator is in the drive
(meaning the encoding method doesn't matter to the end user). FOr
another, head position, etc, is done by sending a command bit-serially to
the drive.
-tony
3:04 p.m.
> 20 years would have to include "RLL"
and ESDI (RLL has same cabling as
> ST412, but different encoding and data-rates? , ESDI cabling looks the
On Thu, 4 Nov 2010, Tony Duell wrote:
Eh? RLL is a date encoding scheme, ST412 is a de-facto
stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
Thanks. I got sloppy. This is one situation where I should have said
"MFM", or clarified the comparison as "ST412 MFM", since I was trying
to
say that the RLL drives were cabled the same, but the data transfer rates
and encoding may be different.
ESDI cabling
looks the same but has signal differences)
It's very different... For one thing
the data separator is in the drive
(meaning the encoding method doesn't matter to the end user). FOr
another, head position, etc, is done by sending a command bit-serially to
the drive.
3:33 p.m.
On 4 Nov 2010 at 15:04, Fred Cisin wrote:
Thanks. I got sloppy. This is one situation where I
should have said
"MFM", or clarified the comparison as "ST412 MFM", since I was
trying
to say that the RLL drives were cabled the same, but the data transfer
rates and encoding may be different.
...and "MFM" as interpreted on an ST412-interface drive can vary
wildly between manufacturers (with respect to ID mark conventions,
CRC/ECC polynomials, etc.).
And then there was "ARLL" that was something like (3,11) (although I
don't remember exactly). Used mostly by Perstor controllers.
I'd be mildly surprised if some enterprising firm didn't try to
record a frame of analog video at 60 fps on an ST412 track. One rev
per frame...
Also, some ESDI drives used hard sectoring.
--Chuck
4:02 p.m.
On 04/11/10 22:33, Chuck Guzis wrote:
I'd be mildly surprised if some enterprising firm
didn't try to
record a frame of analog video at 60 fps on an ST412 track. One rev
per frame...
That would be a bit difficult when the read/write channel is entirely
digital (until it hits the head amp at least).
If you did A->D conversion or some form of PWM, it might be possible.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
5 Nov
5 Nov
3:35 p.m.
I'd be mildly surprised if some enterprising firm
didn't try to
record a frame of analog video at 60 fps on an ST412 track. One rev
per frame...
I am told that the action replays on TV were onc erecorded on a special
hard idsk. One frame per track, fixed heads (so almost instant moving
from one frame to the next) and analogue FM recording.
One of the companies that made them (PPL I think) also sold it as a PDP11
video dispaly peripheral. The special hard disk and a rack of boards (FM
modulato/demodulator, sync, etc). Connected via a DR11-B interace. I have
one.
-tnny
9:32 p.m.
On Fri, 5 Nov 2010, Tony Duell wrote:
Ampex was the pioneer in this particular field I think.
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.simpits.org/geneb - The Me-109F/X Project
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://www.scarletdme.org - Get it _today_!
Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a turd
by the clean end.
I'd be
mildly surprised if some enterprising firm didn't try to
record a frame of analog video at 60 fps on an ST412 track. One rev
per frame...
I am told that the action replays on TV were onc erecorded on a special
hard idsk. One frame per track, fixed heads (so almost instant moving
from one frame to the next) and analogue FM recording.
One of the companies that made them (PPL I think) also sold it as a PDP11
video dispaly peripheral. The special hard disk and a rack of boards (FM
modulato/demodulator, sync, etc). Connected via a DR11-B interace. I have
one.
6 Nov
6 Nov
2:19 p.m.
[Action replay video recording on hard disks)
Ampex was the pioneer in this particular field I
think.
That does not suprise me... Ampex did a lot of interesting stuff with
magnetic recording.
[Incidentally I assume the pun on 'field' is untintentional :-)]
Political correctness is a doctrine, fostered by a
delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a turd
by the clean end.
As I've mentioned before, I really must contact the appropriate
governement department and ask what the politically correct term is for
the radiation emitted by a perfect absorber at temperature T :-)
-tony
6:08 a.m.
ard at p850ug1.demon.co.uk (Tony Duell) writes:
I am told that the action replays on TV were onc
erecorded on a special
hard idsk. One frame per track, fixed heads (so almost instant moving
from one frame to the next) and analogue FM recording.
There are pictures of a couple of these machines on the rather splendid
BBC VT Old Boys site:
http://www.vtoldboys.com/slo60_7.htm
http://www.vtoldboys.com/slo70_3.htm
They've also got some examples of uses for the BBC Micro within VT:
http://www.vtoldboys.com/micro.htm
--
Adam Sampson <ats at offog.org> <http://offog.org/>
5 Nov
5 Nov
3:05 p.m.
> 20 years would have to include
"RLL" and ESDI (RLL has same cabling as
> ST412, but different encoding and data-rates? , ESDI cabling looks the
On Thu, 4 Nov 2010, Tony Duell wrote:
Eh? RLL is a date encoding scheme, ST412 is a
de-facto stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
Thanks. I got sloppy. This is one situation where I should have said "MFM", or clarified the comparison as
"ST412 MFM", since I was trying to
say that the RLL drives were cabled the same, but the data transfer rates
and encoding may be different.
IIRC, the pulse rate at the interface connector is much the same, it's
just a more efficient encoding scheme, using more of the possible patterns.
ESDI
cabling looks the same but has signal differences)
It's very different... For
one thing the data separator is in the drive
(meaning the encoding method doesn't matter to the end user). FOr
another, head position, etc, is done by sending a command bit-serially to
the drive.
4 Nov
4 Nov
3:17 p.m.
On Thu, 4 Nov 2010, Tony Duell wrote:
Eh? RLL is a date encoding scheme, ST412 is a de-facto
stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
ST412 is ALSO a drive that the "de-facto standard" is named after.
They seem to be getting harder to find.
ST412-type of interface) is that in general the
encoding system only
matters to the user on a 'raw' interface,
and, I'd say that the DiscFerret certainly meets MY definitions of a "raw"
interface.
5 Nov
5 Nov
3:14 p.m.
On Thu, 4 Nov 2010, Tony Duell wrote:
It is, indeed. I suspect ST412s are more common than ST406s though That
is not one mf my typos. There is an ST406, it's a single-platter, 2 head
thing, otherwise the same as the ST412. There's also an ST419, which is
the 3 platter 6 head version. The last 2 digits seem to give the
unfrmatted capacity in Mbytes.
Eh? RLL is a date encoding scheme, ST412 is a
de-facto stadnard for the
signals on the drive interface connectors. They are not the same thing at
all.
ST412 is ALSO a drive that the "de-facto standard" is named after.
They seem to be getting harder to find. ST412-type of interface) is that in general the
encoding system only
matters to the user on a 'raw' interface,
and, I'd say that the DiscFerret certainly meets MY definitions of a "raw"
interface.
From what I've heard [1], the diskferet can handle
that sort of thing, so
it could be a raw interfce. On the other hand, with a right
programming
it could als handle a seaprated clock/data type of interface I think.
[1] I will admit I've not looked at the design yet. Mainly because I have
no way of using one. I fully appreciate that with the amount of data that
has to be transfered back to the host machine, you need a fast modern
interface like USB. But I don't hava suitable host.
-tony
5:30 p.m.
Tony Duell wrote:
It is, indeed. I suspect ST412s are more common than
ST406s though That
is not one mf my typos. There is an ST406, it's a single-platter, 2 head
thing, otherwise the same as the ST412.
ST406's are very rare things IME. Even ST506's aren't that common... :-)
(I have serious regrets over selling my Apple ///, just because of the pair of
ST506 drives which went with it)
[1] I will admit I've not looked at the design
yet. Mainly because I have
no way of using one. I fully appreciate that with the amount of data that
has to be transfered back to the host machine, you need a fast modern
interface like USB. But I don't hava suitable host.
I think I would have much preferred SCSI over USB, but you can't please all of
the people etc. and it's still an astounding piece of work.
Whilst most things annoy me unless I can get all the service info, I suppose
I'm just less picky about PCs - I don't mind treating them as a black box,
unlike many other things.
cheers
Jules
6 Nov
6 Nov
12:53 p.m.
Tony Duell wrote:
I know I have one ST406. It's the drive used in the HP9133V unit. The
HP9133XV (which I also have) has an ST419 in it.
The ST406 is very similar to the ST412, to the extent that the main PCB
is the saem (maybe with slightly diffferent jumpering or components
around the head selection area). The ST419 has a somewhat different PCB.
[Diskferret]
It is, indeed. I suspect ST412s are more common
than ST406s though That
is not one mf my typos. There is an ST406, it's a single-platter, 2 head
thing, otherwise the same as the ST412.
ST406's are very rare things IME. Even ST506's aren't that common... :-)
[1] I will
admit I've not looked at the design yet. Mainly because I have
no way of using one. I fully appreciate that with the amount of data that
has to be transfered back to the host machine, you need a fast modern
interface like USB. But I don't hava suitable host.
I think I would have much preferred SCSI over USB, but you can't please all of
the people etc. and it's still an astounding piece of work. Whilst most things annoy me unless I can get all the
service info, I suppose
I'm just less picky about PCs - I don't mind treating them as a black box,
unlike many other things.
That is your choice. I am not at all happy about doing that. In any case,
a modern PC is an expense I can't afford at the moment.
-tony
2 Nov
2 Nov
6:43 p.m.
New subject: DiscFerret: Update 2010-11-03
I've made a bit more progress with the DiscFerret:
* Cost reduction
I found another PCB supplier who can supply PCBs of a similar quality to
the Eurocircuits boards, but at HALF the original price, with full
electrical testing and RoHS compliance thrown in. There is a catch,
though: I have to order a panel of six boards at a time.
Assuming the quality is at least as good as the Eurocircuits boards,
this is what I'll be using for production DiscFerrets.
Bare board cost is now down to ?25 including UK post, down from ?52. The
price for a board with the TPS75003 pre-soldered is set at ?29, or ?4
more than a bare board. This includes me doing a full continuity check
on the TPS75003 and surrounding tracks.
I've ordered half a dozen boards, which gives me ten saleable units.
Depending on how many orders I get, these will probably be a mix of bare
boards and fully assembled and tested boards. I intend to keep a few
boards in stock (the P&P is included in the board price, so "just in
time" ordering is a real possibility).
* Board changes
I've made the pads larger on the Schottky diodes and inductors. It
should now be possible to solder these with a soldering iron!
For obvious reasons I'd suggest a temperature controlled iron (Antex
660TC with TC50 iron, Weller TCP, Xytronic or similar), but you should
be able to get away with using a 25W iron (Antex XS or similar) and a
2.5mm bit.
There are a few 0805 parts nestled amongst the 0603s. I've tweaked the
pads on these so that 0603-sized parts can be fitted in place of the 0805s.
* Reflow profiling
I think I've mentioned that the power controller chip can't be soldered
with a soldering iron. I spent a few hours yesterday ruining parts^W^W
figuring out a usable reflow profile for Multicore RA15 SnAgCu solder
paste... Turns out the process parameters for hot-air are "slightly"
(read: completely) different to the parameters given in the datasheet.
Anyway, it works now, with a small amount of rework needed afterwards
(wicking away a bit of excess solder on the pads).
* Write support
You heard it here first, folks: disc write support has been added to the
DiscFerret microcode! This puts the DiscFerret well in front of the SPS
Kryoflux analyser (which, at the moment, is read-only). I'm working on a
proper test suite for this, but initial results look promising.
There are a few other things I'd like to add before release:
* Head settling time enforcement. The seek logic currently ignores
settling time. This is going to be added before the final spin, come
hell or high water!
* Index frequency measurement. This would be handy for setting up
speed-adjustable drives like the Amstrad/Panasonic EME series 3-inch
units (used in the CPC and PCW series and the Spectrum +3). It should be
possible to get at least one reading per second with a decent amount of
resolution.
The plan is to get some early-production units made up and on sale by
the end of the month, and do another production run early next year if
there's sufficient demand.
Cheers,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
9:28 p.m.
New subject: DiscFerret: Update 2010-11-03
What size are the PC boards, and are you using 2 or 4 layer boards?
What software are you laying out in?
3 Nov
3 Nov
1:50 p.m.
New subject: DiscFerret: Update 2010-11-03
On 03/11/10 04:28, Geoffrey Reed wrote:
What size are the PC boards, and are you using 2 or 4 layer boards?
160x100 Eurocard, 2-layer FR4, 1.6mm thick, 1oz copper, both sides
solder masked, top side component print, 7mil design rules.
What software are you laying out in?
Cadsoft EAGLE 5 Standard. The "Freemium" (if it's still available from
e14) licence is enough to edit the design if you wanted to.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
4:32 p.m.
New subject: DiscFerret: Update 2010-11-03
On 11/3/10 1:50 PM, Philip Pemberton wrote:
On 03/11/10 04:28, Geoffrey Reed wrote:
buried ground plane ? looks like two signal layers with power but no ground
anyway.. looks nice. PIC squirts the config bitstream to the FPGA on reset
or does it come from the host?
What size are the PC boards, and are you using 2 or 4 layer boards?
160x100 Eurocard, 2-layer FR4
4:52 p.m.
New subject: DiscFerret: Update 2010-11-03
On 03/11/10 23:32, Al Kossow wrote:
Ground is on the 'back' (solder) side, but some parts of the PSU (the
high-current parts!) have their own localised ground planes which attach
to the main plane with a grid of vias.
160x100
Eurocard, 2-layer FR4
buried ground plane ? looks like two signal layers with power but no ground anyway.. looks nice. PIC squirts the config bitstream
to the FPGA on reset
or does it come from the host?
It comes from the host.
The PIC runs a simple bootloader which checks to see if a valid firmware
image is loaded. If so, that firmware image is booted, else the PIC
drops into "load" mode. The BOOT jumper can also be used to force entry
into the bootloader.
Once the firmware boots, it waits for a USB connection, then enumerates
with the host. The host sends a microcode image to the PIC, which then
squirts it into the FPGA over the Passive Serial Configuration Link.
Basically, it reads the RBF file, bitswaps each byte, then feeds it to
the PIC.
When the microcode is loaded, the host does a quick check to make sure
the FPGA accepted the bitstream, then queries the microcode type ID and
version. After that you program registers on the chip to make it "do
stuff". POKE, PEEK and all that jazz :)
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
7:47 p.m.
New subject: DiscFerret: Update 2010-11-03
On 04/11/10 02:34, David Ryskalczyk wrote:
It already *is* a two layer design with no buried planes... why get rid
of the ground fills? They're good for improving the EMC and signal
integrity figures, among other things...
If you wanted 4-layer then that's doable too, but expect the boards to
double in price.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
> buried
ground plane ? looks like two signal layers with power but no
> ground
Hmm ... would this be possible with a two-layer design, and no planes?
3:42 p.m.
New subject: DiscFerret: Update 2010-11-03
On 03/11/10 19:39, Al Kossow wrote:
On 11/2/10 6:43 PM, Philip Pemberton wrote:
Now. :)
http://hg.discferret.com/
I'll try and get some PDFs put online tonight, and add this link to the
project homepage. For now, that URL links to the version control
repository which contains the EAGLE schematics/PCB layouts, firmware,
and FPGA microcode. I've also thrown in a few Python test scripts but
they probably won't make much sense given that they were written as
quick hacks...
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
There are a few other things I'd like to add
before release:
when would you be putting the design on line to look at?
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