>>> ???! The value for R must be a valid sector number. For floppies
>>> that is never zero.
>>There are a lot of floppies with sector numbers starting with 0.
>>765 can read them and write them.
>
>Maybe... there are caveats on that. Technically a sector number of 0
>should not be used.
>
>Did a lot of work at "NEC" (US arm then was NEC Micromputers USA, then later
>NEC Electronics USA.) in the early years when they were developing and
>marketing that and a HDC. I was on the hardware/technical side.
When I designed the 765 based disk system in my D6809/CUBIX system, I "didn't
know better" and numbered the sectors within a track from zero - this would
have been early to mid 80's.
Never changed it, as it has never caused a problem - versions of this system
were built with both NEC and Intel (8272) controllers, and used for many years.
ImageDisk reads and recreates CUBIX disks with no problems.
I cannot find any information in the NEC data sheet which describes any
restriction on the sector number (other than that it is one byte) - can you
provide a reference to these caveats? this is the first I've heard of them.
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
>
>Subject: Re: Grrr - !%#*^@# Kaypro!
> From: Fred Cisin <cisin at xenosoft.com>
> Date: Wed, 03 Aug 2005 19:12:06 -0700 (PDT)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Wed, 3 Aug 2005, Allison wrote:
>> >> Dave, your on track. The CHRN vlaues do not have to corrospond
>> >> to actual head or cylinder. They do not even have to be in order
>> >> on the media! The only limits on them are R must be 1 or greater
>> >> (less than 255).
>> >
>> >Which creates some complications with handling 128 byte sectors (R==0).
>
>Sorry, TYPO. I got sloppy and thought that you were saying the sector
>size value could not be 0
>
>> ???! The value for R must be a valid sector number. For floppies
>> that is never zero.
>There are a lot of floppies with sector numbers starting with 0.
>765 can read them and write them.
Maybe... there are caveats on that. Technically a sector number of 0
should not be used.
Did a lot of work at "NEC" (US arm then was NEC Micromputers USA, then later
NEC Electronics USA.) in the early years when they were developing and
marketing that and a HDC. I was on the hardware/technical side.
Allison
>
>Subject: Re: Grrr - !%#*^@# Kaypro!
> From: Fred Cisin <cisin at xenosoft.com>
> Date: Wed, 03 Aug 2005 16:08:22 -0700 (PDT)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Wed, 3 Aug 2005, Allison wrote:
>> Dave, your on track. The CHRN vlaues do not have to corrospond
>> to actual head or cylinder. They do not even have to be in order
>> on the media! The only limits on them are R must be 1 or greater
>> (less than 255).
>
>Which creates some complications with handling 128 byte sectors (R==0).
???! The value for R must be a valid sector number. For floppies
that is never zero.
>
>> My favorite format was sectors 1- 9 (512 DD) on side one and
>> side two was 10-19 with H always set to 0.
>
>Easily handled by 765, but not by Int13h.
;-) Plays havoc with many systems not expecting it.
>I have to be careful to differentiate which complications are
>due to the FDC chip, which to the FDC board/implementation,
>and which are BIOS linitations.
Yep, The bios for the most part is a not a limiting factor if you program
around it. Its the board implmentations or the chips that replace
board implmentations that really are poor.
>Nitpick: don't you mean 0 - 9 on first side? Or did it actually have 9
>sectors on one side and 10 sectors on the other?
;) That was why it was pretty wild. it was done for a joke in the lab
but no one could sort it out.
>I've seen disks with 10h and 20h in the H field.
Yep, CHRN are supposed to carry Cylinder, Head, Record(sector) and
N=data length. But the allowable values are usually 0 or 1 to 255.
One engineer at Bell Labs used a 765 to make a nice block replaceable
DC300 tape system. He used R and H to form a 16 bit block number.
This was back in 1981 so it predates the PC based tape on floppy backup.
>And, of course, there are some formats, such as Superbrain,
>where the data (sector content) is inverted,
>but the headers (CHRN) are not.
that really bothered people for some reason.
Allison
If one or two of you with a working board want to try one, I have some 6 GB
CF dives I need tested. I'll send you one if you promise to send me back a
report on how it worked, performance, problems, etc. Use this email:
billy.pettit at wdc.com
Billy
On Sun, 2005-07-31 at 08:56 -0400, Steven N. Hirsch wrote:
> On Sat, 30 Jul 2005, Zane H. Healy wrote:
>
> > > Hi,
> > >
> > > Check this out:
> > >
> > >
<http://dreher.net/?s=projects/CFforAppleII&c=projects/CFforAppleII/mai>
> > > n.php
> > >
> > > Great way to do instead of relying on aging floppies.
> > >
> > > Cheers, Wizard
> >
> > Interesting, anyone have any experience with this?
>
> Yes, works great. One of the coolest gadgets ever for the A2.
Worked pretty good for me too. I've got one in a IIgs. If you read the
forums however, he does warn that some CF cards are not compatible w/
the thing. I had good luck w/ some little 128Mb SanDisk CF cards.
David
> There was once a show in California called The West
> Coast Computer Fair. When it first started it was one
> of the most interesting shows I've ever been to. They
> had a really nice mix of large vendors and small
> companies. Some even just had exhibits without any
> specific sales ( they did advertise ).
Interesting, I've never heard of this show before now. Can
you tell me more about how it was similar to and different
>from VCF East 1 or 2?
--
I have the first WCCF proceedings on bitsavers under computerFaire
This was run by Jim Warren (of Dr. Dobb's fame)
Contemporary with the earliest Trenton shows.
Someone listed an IMSAI 8080 on the VCM for the relatively reasonable
price of $1,300:
http://marketplace.vintage.org/view.cfm?ad=1973
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
>From: "Dwight K. Elvey" <dwight.elvey at amd.com>
>
>>From: "Fred Cisin" <cisin at xenosoft.com>
>>
>>On Wed, 3 Aug 2005, Dave Dunfield wrote:
>>> Tried ImageDisk on some Kaypro disks this morning...
>>> Buggers recorded side1 as additional sectors of side0.
>>> The different set of sector numbers didn't bother
>>> ImageDisk, but it had a bit of a tantrum with the Head
>>> ids which didn't match the physical head selection.
>>
>>Quite common :-(
>>765 insists on accurate sector headers;
>>WD 179x can ignore the head # field in the sector headers.
>>The Kaypro won't even mind reading/writing a disk,
>>if you FORMAT it with a 765 using valid sector headers!
>>
>>
>>> I can imagine that someone somewhere does weird things
>>> with the Cylinder ids on a track as well ...
>>
>>Rare. I've only seen it a few times.
>>
>
>Hi
> At least for Dave's setup, he could get by with
>a bypass switch on the head selector. It is always
>funny what different setups have done. At least there
>is a potential bypass for this one.
> I'd guess the fellow that wrote the driver for the
>Kaypro didn't have a problem so he didn't notice the
>missing head information in the sector header. He
>may have thought the controller took care of this
>somehow. I know when I've fiddled with the disk controller
>directly, it isn't always clear when and where
>each register takes effect. There are a few places
>that it seem that there is redundant information.
>Dwight
>
Hi
I see from Dave's post that this was one of those redundant
information I was talking about. I wonder if all the
later PC controllers deal with these fields the same?
Dwight
>> Yes. - What happens when the catweasel becomes unavailable?
>
>What happens when (disk controller of choice) become unavailable? :)
So ... just to make sure I understand you - you are suggesting that
a catweasle (how many have been made?) will be more obtainable than
a WD disk controller chip (LOTS made) ...?
>> A grave omission for something thats supposed to archive
>> non-PC-standard disks.
>
>If you're supposing the user can wire up a disk controller, why can't
>they wire up a simple 34(SA400) to 50(SA800) pin adapter cable? Also,
>you can buy an SA400/SA800 adaptor board that someone has made, which
>properly controls the TG43 line. Unfortunately, I can't remember the
>name of the board or who made it right now.
Missed point - if the device is intended to support non-PC disk formats,
then why not support 8" drives - it's not hard. Why should you have to
buy another board to performs the devices primary function.
Also note, that what I proposed would have the 8" interface on it, so
the case you mention does not occur - it's the guy who bought the cat
(and didn't build a controller) who has to wire up the adapter cable -
you have your argument backwards.
>> But would have tied the thing to one particular development
>> environment (Here's you VisualC++ library - have a nice day). The
>> best solution is a fully open and documented description of the
>> hardware and lots of sample code.
>
>There's no reason a bit of C wrapper code has to be tied to any
>particular 'development environment'.
Not the way it works in my experience (25+ years in embedded development
systems/tools) - invariably there will be unreleased source, or library
functions which make it tough to use elsewhere. I much prefer good docs
on the hardware to wading through reams of un/poorly docuemnted source
code.
>I'd say that by ignoring (specifically) Apple ][ and C64, you're missing
>a large percentage of possible software/users.
another missed point ... anyone who's been following my work knows that I
have implemented a number of systems to cheaply archive, distribute and
restore disk images for various systems. This would have been just another
piece in the puzzle. Such systems already exist (and I use them) to archive
AppleII and C64 images.
>> Still deciding if it's worth it - I'll record your "NO" vote.
>
>Not to discourage you, but, I'd echo the sentiment above. I'd suggest
>that if you do want to produce something, make something that can read
>the disk on a flux-transition level, and store that sort of data.
>Something nice and generic. That way, you can do all the processing in
>software, and handle any format of disk that comes your way.
lots of other arguments snipped.
Ok - I don't need to get dumped on anymore. Consider the idea dropped...
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
I've posted the latest version of ImageDisk and some 8" images that
I have archived with it on my classic collection page:
http://www.parse.com/~ddunfield/museum/index.html
Look under "Disks/Software images" near the bottom of the page.
Here's the images I've posted today:
IMD 130k Compupro CP/M 2.2 for Disk1A
IMD 330k Compupro CP/M 86 for Disk1A
IMD 305k Cromemco Cromix 11.26 (8")
IMD 300k Cromemco CDOS 2.58 (8" amd 5.25")
IMD 190k Cromemco CP/M for 16FDC (8")
IMD 995k Dy4 Orion-V System Disks
IMD 425k IMS TurboDOS 1.31
IMD 48k Nabu 1100 CP/M (8")
IMD 425k NEC APC System Disks (Demo & CP/M-86)
IMD 265k NEC NS5200 MS-DOS 2.11
IMD 210k TRS-80 Model II TRSDOS & CP/M
IMD 68k Xerox 820-II CP/M
I'll have a number of the existing TeleDisk 5.25" images
redone under ImageDisk posted within the next few days.
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
Someone contacted me about donating a Inex 4000 6800 microcomputer, vintage
1978 with lots of cool development software for it. Anyone here know
anything about it and also a value for it? thanks John
