2 Mar
2011
2 Mar
'11
2:10 p.m.
On Wed, Mar 2, 2011 at 1:52 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
One other nice featuroe of these drives is a slotted
optoswtich near the
head carrarriage that changes state at cylinder 43. This is used (I think
it's a jumper-selected option) to reduce the write current, so you don't
need to provide the TG43 signal from the controller. Very handy if you're
using them with a PC/AT controller ;-)
I know it's easy to generate this signal with an inexpensive
microcontroller, but I'm curious what drives have this feature. I
have a TM848 (can't remember if it's -1 or -2 - I'd probably have to
pull it from the Dataram Qbus chassis it's in to check, but since it's
meant to emulate an RX02, it's *probably* a TM848-1) that I was
planning on rigging to a PC-class machine at some point to image my
pile of RX01 and box of CP/M 8" floppies.
Of course with all the DEC gear I have, I might as well look into
using vtserver to pull down RX01 _and_ RX02 images from a real RX02
drive, but I still have plans to build a PC-based multi-media floppy
imaging box, so I'm keeping my eye out for a preferred model of 8"
drive for that purpose.
So far, I really only know a little bit about the SA800s and the
TM848s (and the Calcomps used in RX01s and RX02s, but I'm not likely
to hang one of those off of a PC). Anyone have any recommendations
for good drives to use with PCs?
-ethan
2 Mar
2 Mar
3:45 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On 3/2/11 2:10 PM, Ethan Dicks wrote:
Anyone have any recommendations
for good drives to use with PCs?
I've been using a QumeTrak 242 (Ye-Data 180) exclusively for 8" recovery for
a couple of years now.
3:57 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Wed, 2 Mar 2011, Al Kossow wrote:
On 3/2/11 2:10 PM, Ethan Dicks wrote:
I'm using a Tandon TM848-02 with a D Bit FDADAP connector board. It
isn't strictly necessary for the 848, but it's handy.
Mike Loewen mloewen at cpumagic.scol.pa.us
Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
Anyone have any recommendations
for good drives to use with PCs?
I've been using a QumeTrak 242 (Ye-Data 180) exclusively for 8" recovery for
a couple of years now. 
4:18 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On 2 Mar 2011 at 15:45, Al Kossow wrote:
On 3/2/11 2:10 PM, Ethan Dicks wrote:
Qume DT/8 here. Great drive. Also a couple of Siemens FDD-200
drives--one set up to read hard-sectored and filter out the sector
marks (providing only index), the other set "raw".
--Chuck
Anyone have any recommendations
for good drives to use with PCs?
I've been using a QumeTrak 242 (Ye-Data 180) exclusively for 8"
recovery for a couple of years now. 
3 Mar
3 Mar
8:58 a.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Wednesday (03/02/2011 at 04:18PM -0800), Chuck Guzis wrote:
Also a couple of Siemens FDD-200
drives--one set up to read hard-sectored and filter out the sector
marks (providing only index), the other set "raw".
What is the theory of operation behind a hard-sector filter? I believe
I have seen this done with just a one-shot but I'm not sure I understand
how that eliminates only the sector marks, leaving just index? It seems
like with just a one-shot, it would sync to any hole and call that index.
Chris
--
Chris Elmquist
9:22 a.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On 3 Mar 2011 at 10:58, Chris Elmquist wrote:
What is the theory of operation behind a hard-sector
filter? I
believe I have seen this done with just a one-shot but I'm not sure I
understand how that eliminates only the sector marks, leaving just
index? It seems like with just a one-shot, it would sync to any hole
and call that index.
One of the things that makes this easy for 8" drives is that, but for
a few very early types, all 8" HS floppies are 33-hole (32 sectors +
index).
The index on an 8" HS floppy is located midway between two sector
holes. So, for example, if you use a one-shot whose output width is
set to, say, 2/3rds of the time between index holes, any hole
occurring under that "umbrella" must be an index--so you generate an
"index" pulse. Very simple, actually.
--Chuck
6:15 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Thursday (03/03/2011 at 09:22AM -0800), Chuck Guzis wrote:
On 3 Mar 2011 at 10:58, Chris Elmquist wrote:
Ah... I see now. The one-shot is used as a gate and if another index
pulse comes in while the gate is "open", then you let that pulse pass.
Thanks. Makes sense.
This should apply to 5.25" hard-sector too. Same concept.
Chris
--
Chris Elmquist
What is the theory of operation behind a
hard-sector filter? I
believe I have seen this done with just a one-shot but I'm not sure I
understand how that eliminates only the sector marks, leaving just
index? It seems like with just a one-shot, it would sync to any hole
and call that index.
One of the things that makes this easy for 8" drives is that, but for
a few very early types, all 8" HS floppies are 33-hole (32 sectors +
index).
The index on an 8" HS floppy is located midway between two sector
holes. So, for example, if you use a one-shot whose output width is
set to, say, 2/3rds of the time between index holes, any hole
occurring under that "umbrella" must be an index--so you generate an
"index" pulse. Very simple, actually.
6:35 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On 3 Mar 2011 at 20:15, Chris Elmquist wrote:
This should apply to 5.25" hard-sector too. Same
concept.
Yes, but a little trickier--5.25" disks come in more than one sector
hole pattern.
--Chuck
4 Mar
4 Mar
10:12 a.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Thursday (03/03/2011 at 06:35PM -0800), Chuck Guzis wrote:
On 3 Mar 2011 at 20:15, Chris Elmquist wrote:
oh sure... you just have to choose the one-shot timing appropriately.
But then I am not sure why I want to do this on 5.25" media :-)
--
Chris Elmquist
This should apply to 5.25" hard-sector too.
Same concept.
Yes, but a little trickier--5.25" disks come in more than one sector
hole pattern. 
3 Mar
3 Mar
7:21 p.m.
New subject: Reading Microcontrollers.
I need to pull the rom image off of a MC705C8acpe, anyone know how? Or if it
is possible?
7:55 p.m.
New subject: Reading Microcontrollers.
It has an SPI (Serial Program Interface) so it should conform to a
standard MOSI/MISO/RESET/SCK interface.... so I you can tap the pinouts
of it, apply gnd and power to it and hook it up to an ISP programmer,
you should be able to read in the code from it and save it as a bin or
hex file.
Here's the datasheet:
http://www.ic-on-line.cn/IOL/viewpdf/MC705C8ACFNR2_393498.htm
I work with Atmel and Microchip MCU's a lot so its fairly similar, never
worked with Motorola MCU's before though....
Geoffrey Reed wrote:
I need to pull the rom image off of a MC705C8acpe,
anyone know how? Or if it
is possible?
4 Mar
4 Mar
10:37 a.m.
New subject: Reading Microcontrollers.
On Thursday (03/03/2011 at 10:55PM -0500), Curt @ Atari Museum wrote:
It has an SPI (Serial Program Interface) so it should
conform to a
standard MOSI/MISO/RESET/SCK interface.... so I you can tap the pinouts
of it, apply gnd and power to it and hook it up to an ISP programmer,
you should be able to read in the code from it and save it as a bin or
hex file.
well, no. Not exactly. The SPI on these devices is not used to program or
in any way access the EPROM on the devices without the 6805 participating
in such transfers.
They do have a ROM that facilitates programming and dumping of the EPROM
and it does this through the serial (SCI) port. However they also have
a security bit which if set, prevents verifying and dumping the EPROM.
So, you _could_ dump the EPROM, via the serial port, using the on-chip
ROM code but only if that security bit has not been programmed.
Here's the datasheet:
http://www.ic-on-line.cn/IOL/viewpdf/MC705C8ACFNR2_393498.htm
section 9.4.8 on page 115 discusses dumping the EPROM...
Geoffrey Reed wrote:
> I need to pull the rom image off of a MC705C8acpe, anyone know how? Or if it
> is possible?
--
Chris Elmquist
1:09 p.m.
New subject: Reading Microcontrollers.
Thanks for the clarification Chris, as I mentioned I work with Atmel and
Microchip MCU's, so I wasn't 100% sure on the Motorola unit.
Chris Elmquist wrote:
On Thursday (03/03/2011 at 10:55PM -0500), Curt @
Atari Museum wrote:
It has an SPI (Serial Program Interface) so it
should conform to a
standard MOSI/MISO/RESET/SCK interface.... so I you can tap the pinouts
of it, apply gnd and power to it and hook it up to an ISP programmer,
you should be able to read in the code from it and save it as a bin or
hex file.
well, no. Not exactly. The SPI on these devices is not used to program or
in any way access the EPROM on the devices without the 6805 participating
in such transfers.
They do have a ROM that facilitates programming and dumping of the EPROM
and it does this through the serial (SCI) port. However they also have
a security bit which if set, prevents verifying and dumping the EPROM.
So, you _could_ dump the EPROM, via the serial port, using the on-chip
ROM code but only if that security bit has not been programmed.
Here's the datasheet:
http://www.ic-on-line.cn/IOL/viewpdf/MC705C8ACFNR2_393498.htm
section 9.4.8 on page 115 discusses dumping the EPROM...
Geoffrey Reed wrote:
> I need to pull the rom image off of a MC705C8acpe, anyone know how? Or if it
> is possible?
>
11:17 a.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD:
The index on
an 8" HS floppy is located midway between two sector
holes. So, for example, if you use a one-shot whose output width is
set to, say, 2/3rds of the time between index holes, any hole
occurring under that "umbrella" must be an index--so you generate an
"index" pulse. Very simple, actually.
Ah... I see now. The one-shot is used as a gate and if another index
pulse comes in while the gate is "open", then you let that pulse pass.
Thanks. Makes sense.
This should apply to 5.25" hard-sector too. Same concept.
2 Mar
2 Mar
4:21 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On those Tandon 848s, note that the on-board regulator that drops 24V
to 12 is given to overheating. If your drive doesn't have a parallel
pass resistor across the 7812 regulator, it might be a good idea to
install one. Part of the field change was also to include an
electrolytic cap after the regulator--about 100 uF at 50V. Often,
these go toes-up, so if an 848's not working, start there.
--Chuck
10:22 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Wed, Mar 2, 2011 at 7:21 PM, Chuck Guzis <cclist at sydex.com> wrote:
On those Tandon 848s, note that the on-board regulator
that drops 24V
to 12 is given to overheating....
Good tip. Thanks. I know the drive isn't inert, but I do recall that
it didn't seem to be reliable when it was new. I'll definitely check
that part of the board when I dig it out.
-ethan
4:46 p.m.
New subject: Possible Security risk
Hi
I just opened a post from someone named TOM and the
subject was: My posts
Semitec stopped it from doing some type of download.
Read with caution.
Dwight
4:49 p.m.
New subject: Possible Security risk
On 3/2/11 6:46 PM, dwight elvey wrote:
Hi
I just opened a post from someone named TOM and the
subject was: My posts
Semitec stopped it from doing some type of download.
Read with caution.
As far as I know, the classiccmp server still strips attachemnts.
Even with full HTML enabled, the "My posts" email shows no binary code
or attachment here.
Doc
4:57 p.m.
New subject: Possible Security risk
At 4:46 PM -0800 3/2/11, dwight elvey wrote:
Hi
I just opened a post from someone named TOM and the
subject was: My posts
Semitec stopped it from doing some type of download.
Read with caution.
Dwight
Seems like a totally innocent post, it's one of two prior to this I'd
actually bothered to look at today.
I wonder if the problem was the Apple character in the .sig, or if my
ISP stripped part of it.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com | OpenVMS Enthusiast |
| | Photographer |
+----------------------------------+----------------------------+
| My flickr Photostream |
| http://www.flickr.com/photos/33848088 at N03/ |
4:59 p.m.
New subject: Possible Security risk
That was me. Tom Peters, Milwaukee area. Ask Al K
who I am. There was no attachment, but I did send
it in HTML format. Ooops. I won't do that any more.
-T
At 06:46 PM 3/2/2011, you wrote:
Hi
I just opened a post from someone named TOM and the
subject was: My posts
Semitec stopped it from doing some type of download.
Read with caution.
Dwight
650 . [Faith] Many people want the benefits of
the church, but choose not to be of benefit to the church. -- Author Unknown
NEW: a50mhzham at gmail.com ? N9QQB (amateur radio)
"HEY YOU" (loud shouting) ? Second Tops (Set Dancing) ? FIND ME ON FACEBOOK
43? 7' 17.2" N by 88? 6' 28.9" W ? Elevation 815' ? Grid Square
EN53wc
LAN/Telecom Analyst ? Open-source Dude ? Musician
? Registered Linux User 385531
3 Mar
3 Mar
6:10 p.m.
New subject: Thanks ! Re: Possible Security risk
Thanks !
I got it too and will not open it due to your alert.
We all have to be so carful today !
Frank
-----Original Message-----
From: dwight elvey <dkelvey at hotmail.com>
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Sent: Wed, Mar 2, 2011 7:49 pm
Subject: Possible Security risk
i
I just opened a post from someone named TOM and the
ubject was: My posts
Semitec stopped it from doing some type of download.
ead with caution.
wight
6:11 p.m.
New subject: Thanks ! Re: Possible Security risk
Well...not ALL of us.. ;)
-Dave
On 3/3/11 9:10 PM, fjgjr1 at aol.com wrote:
Thanks !
I got it too and will not open it due to your alert.
We all have to be so carful today !
Frank
-----Original Message-----
From: dwight elvey<dkelvey at hotmail.com>
To: General Discussion: On-Topic and Off-Topic Posts<cctalk at classiccmp.org>
Sent: Wed, Mar 2, 2011 7:49 pm
Subject: Possible Security risk
i
I just opened a post from someone named TOM and the
ubject was: My posts
Semitec stopped it from doing some type of download.
ead with caution.
wight
--
Dave McGuire
Port Charlotte, FL
4 Mar
4 Mar
5:59 a.m.
New subject: Thanks ! Re: Possible Security risk
On Thu, 3 Mar 2011, Dave McGuire wrote:
Well...not ALL of us.. ;)
-Dave
On 3/3/11 9:10 PM, fjgjr1 at aol.com wrote:
>
> Thanks !
>
> I got it too and will not open it due to your alert.
>
> We all have to be so carful today !
>
> Frank
>
Just think, there is some poor dork out there madly trying to figure out
how to make Alpine execute attachments...
*snickers*
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.
7:34 a.m.
New subject: Thanks ! Re: Possible Security risk
On 3/4/11 8:59 AM, Gene Buckle wrote:
ROFL!!
--
Dave McGuire
Port Charlotte, FL
Well...not ALL of us.. ;)
-Dave
On 3/3/11 9:10 PM, fjgjr1 at aol.com wrote:
>
> Thanks !
>
> I got it too and will not open it due to your alert.
>
> We all have to be so carful today !
Just think, there is some poor dork out there madly trying to figure out
how to make Alpine execute attachments...
*snickers*
2 Mar
2 Mar
11:31 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD:
On 3/2/11 2:10 PM, Ethan Dicks wrote:
Perhaps I shpuld point out the obvious and say that the TG43 signal is
irrelevant when reading. If what you want to do is make images of disks,
you don't need to worry wheter hthe drive generates this signal or what.
But if you want to writhe imaged back to a real 8" disk, it becomes
important.
-tony
Anyone have any recommendations
for good drives to use with PCs?
I've been using a QumeTrak 242 (Ye-Data 180) exclusively for 8" recovery for
a couple of years now. 
6 p.m.
New subject: TG43 signal and 8" drives on commodity hardware (was Re: WTD: 8-inch floppy drive)
On Wed, 2 Mar 2011, Ethan Dicks wrote:
Anyone have any recommendations
for good drives to use with PCs?
Panasonic YE-380 1/2-height. Very quiet and trouble-free. I believe
these were the final generation of 8" drives - used mostly in medical
imaging equipment.
--
4824
days inactive
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25 comments
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participants (16)
-
a50mhzham＠gmail.com -
aek＠bitsavers.org -
ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
chrise＠pobox.com -
curt＠atarimuseum.com -
dkelvey＠hotmail.com -
doc＠vaxen.net -
ethan.dicks＠gmail.com -
fjgjr1＠aol.com -
geneb＠deltasoft.com -
geoffr＠zipcon.net -
healyzh＠aracnet.com -
mcguire＠neurotica.com -
mloewen＠cpumagic.scol.pa.us -
snhirsch＠gmail.com