subject:"Re\: Installing an operating system on the 11\/83 \- update."

On Tue, Feb 22, 2022, 8:43 PM Jay Jaeger via cctalk 
wrote:

> On 2/22/2022 6:12 PM, js--- via cctalk wrote:
> >
> > On 2/22/2022 7:00 PM, Ray Jewhurst wrote:
> >> I read that you can indeed use a standard 1.2 Meg drive and that you
> >> can also use DSHD 5.25 disks in place of RX50s. Is there any truth in
> >> this? If there is it will be much easier and cheaper to make disks for
> >> my Rainbow.
> >
> >
> > As Chuck noted, I'd think you'd want to use 360K media -- not DSHD
> > diskettes... and ensure that the 1.2MB drive is slowing down to 300RPM
> > with a data rate of 250KHZ.
> >
> > These features will depend on the 1.2MB drive you have, as well as your
> > FDC and imaging software.
> >
> > - John Singleton
>
> Writing a 360KB or RX50 diskette with a 1.2MB drive is a path to a lot
> of frustration.  Not only do you have to double step the drive (software
> often takes care of that part), but the tracks written will be narrower
> than a real RX50 / 306KB drive, providing a smaller signal/noise ratio.

Not true. Not for RX50 at least. Both the 1.2MB format and the RX50 format
use 80 tracks. There is no double stepping or half width tracks involved.

>   And, if you don't start with completely magnetically erased media, any
> left over junk in any data left over may be picked up by the RX50 head.
>

Also not true. Writing a full track to format it results in well formed
media. As long as you don't use HD media. DD or QD media works just fine.

Been there, done that.
>

I have as well, and things don't work the way you say. The TEAC 55 drives
are able to do this. In college I exchanged data between a data collection
AT and a MicroVAX ii on RX50 media. It was sometimes formatted on my
Rainbow at home and later on the AT since I got tired of being in the loop.
We had none of these problems as long as we avoided HD media.

Warner

> JRJ
>

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Jay Jaeger via cctalk


On 2/22/2022 6:12 PM, js--- via cctalk wrote:


On 2/22/2022 7:00 PM, Ray Jewhurst wrote:
I read that you can indeed use a standard 1.2 Meg drive and that you 
can also use DSHD 5.25 disks in place of RX50s. Is there any truth in 
this? If there is it will be much easier and cheaper to make disks for 
my Rainbow.



As Chuck noted, I'd think you'd want to use 360K media -- not DSHD 
diskettes... and ensure that the 1.2MB drive is slowing down to 300RPM 
with a data rate of 250KHZ.


These features will depend on the 1.2MB drive you have, as well as your 
FDC and imaging software.


- John Singleton


Writing a 360KB or RX50 diskette with a 1.2MB drive is a path to a lot 
of frustration.  Not only do you have to double step the drive (software 
often takes care of that part), but the tracks written will be narrower 
than a real RX50 / 306KB drive, providing a smaller signal/noise ratio. 
 And, if you don't start with completely magnetically erased media, any 
left over junk in any data left over may be picked up by the RX50 head.


Been there, done that.

JRJ

Re: Installing an operating system on the 11/83 - update.


Corrections:

I think that Mike Gingel did both a program on PC for read/write TRS-DOS 
family, AND did one on TRS-DOS for other formats.  I don't remember which 
one was which, but I think that the one running on TRS80 might 
be "Hypercross", with "PC Cross Zap"? being the one running on PC?

http://www.oldcomputers.it/parts/r/radio/TRS80_4/docs/trs80-xf.htm

Roxton Baker was the author of TRAKCESS.  I remember Alan Gelder (TBug 
enhancements) helped Baker with the machine language portions.

https://www.classic-computers.org.nz/system-80/software-manuals/manuals-trakcess-1.95.pdf


Harv Pennington's first book (before he got carried away) was "TRS80 Disk 
And Other Mysteries".  Later on, he even got involved in marketing 
a port of Michael Shrayer's "Electric Pencil" to PC!




On Tue, 22 Feb 2022, Fred Cisin via cctalk wrote:


On Tue, 22 Feb 2022, Bill Gunshannon via cctalk wrote:

Hmmm..  I wonder if I could do any of this with my OS9 system
running on a Tandy COCO?  Lot's of ability to fudge with disk
formats and you can't find a controller much older.  :-)
Makes me wonder about the other old TRS80's.  All handle 5.25
floppies and have old controllers.  And OSes that let you do
pretty much anything you want.  Even shoot yourself in the foot.

I wonder if I even have any RX50 floppies laying still around
here anywhere?


Certainly!

The Coco used a Western Digital 179x controller.  I don't remember which 
specific one, and for simple stuff like this, it won't matter much.


The WD doesn't have the "flash blindness" that sometimes interferes with the 
NEC 765 series when reading disks where the first sector is too soon after 
the index pulse.
The WD has a semi-raw track read that is real handy (The NEC has a multiple 
sector read, but not a raw track read)



There have been some programs on the Coco for reading and writing some other 
formats.   ISTR Dr. Marty did one on the Coco for reading PC disks. (probably 
published in Rainbow)


The TRS80 Model 3 and 4 also used 179x controllers.  With very different 
operating systems (The Randy Cook family of OS).  Look for  by 
Mike Gingel, as a program running on TRS80.
Also, "Trakcess" is very handy for analyzing disks, although you need to do 
some trivial mods to it for double sided, etc.
Looking at the program of Trakcess will make it easy to get the basics to do 
almost anything that you want to do.

William Barden did a nice pamphlet on disk I/O for TRS80.
Then Harv (HC) Pennington wrote very extensively about the internals of 
TRS-DOS.



Until August 1981, when the 5150 came out, my disk format conversion work was 
on TRS80.



The TRS80 model 1 used the 1771 controller which was single density only. 
And, the original SA400 single sided drive on it only got 35 tracks.
Be careful, the second side signal on the cable is used on the Model 1 as 
drive select for the fourth drive!  (Tandy wasn't planning on DS drives)

But, the retrofit "Doubler" added a 179x controller.


As a REAL programmer, you can shoot yourself in the foot with any language or 
operating system!   (Is that the definition of programmer?)


--
Grumpy Ol' Fred ci...@xenosoft.com

Re: Installing an operating system on the 11/83 - update.


On Tue, 22 Feb 2022, Bill Gunshannon via cctalk wrote:

Hmmm..  I wonder if I could do any of this with my OS9 system
running on a Tandy COCO?  Lot's of ability to fudge with disk
formats and you can't find a controller much older.  :-)
Makes me wonder about the other old TRS80's.  All handle 5.25
floppies and have old controllers.  And OSes that let you do
pretty much anything you want.  Even shoot yourself in the foot.

I wonder if I even have any RX50 floppies laying still around
here anywhere?


Certainly!

The Coco used a Western Digital 179x controller.  I don't remember which 
specific one, and for simple stuff like this, it won't matter much.


The WD doesn't have the "flash blindness" that sometimes interferes with 
the NEC 765 series when reading disks where the first sector is too soon 
after the index pulse.
The WD has a semi-raw track read that is real handy (The NEC has a 
multiple sector read, but not a raw track read)



There have been some programs on the Coco for reading and writing some 
other formats.   ISTR Dr. Marty did one on the Coco for reading PC disks. 
(probably published in Rainbow)


The TRS80 Model 3 and 4 also used 179x controllers.  With very different 
operating systems (The Randy Cook family of OS).  Look for "TRSCross"?, by 
Mike Gingel, as a program running on TRS80.
Also, "Trakcess" is very handy for analyzing disks, although you need to 
do some trivial mods to it for double sided, etc.
Looking at the program of Trakcess will make it easy to get the basics 
to do almost anything that you want to do.

William Barden did a nice pamphlet on disk I/O for TRS80.
Then Harv (HC) Pennington wrote very extensively about the internals of 
TRS-DOS.



Until August 1981, when the 5150 came out, my disk format conversion work 
was on TRS80.



The TRS80 model 1 used the 1771 controller which was single density only. 
And, the original SA400 single sided drive on it only got 35 tracks.
Be careful, the second side signal on the cable is used on the Model 1 as 
drive select for the fourth drive!  (Tandy wasn't planning on DS drives)

But, the retrofit "Doubler" added a 179x controller.


As a REAL programmer, you can shoot yourself in the foot with any language 
or operating system!   (Is that the definition of programmer?)


--
Grumpy Ol' Fred ci...@xenosoft.com

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Bill Gunshannon via cctalk

On 2/22/22 20:08, Paul Koning via cctalk wrote:

On Feb 22, 2022, at 7:33 PM, Fred Cisin via cctalk
wrote:

From the FDC point of view, which doesn't have optical view of the drive and media, the 80
track DD 5.25" looks similar to a "720K 3.5" drive.
(80 tracks, 9 sectors per track, 300 RPM, 250K data transgfer rate)

On SOME PCs, setting the CMOS floppy setting to "720K" may take care of it.

Originally I wrote my RX50 floppies on a Windows PC. The drive was a plain old
5.25 inch PC drive, normally used for 9 sector per track PC floppies. It turns
out some BIOS operations will reset it to 10 sectors, which is RX50 format, and
then BIOS int13 operations can read and write it. I coded up support for that
in RSTSFLX, which can be found on my Subversion server (in branches/V2.6). The
original version was built with Borland C++, but I switched to DJGPP which made
all that much easier. No CMOS or other magic needed, just an application that
knows how to speak int13. And of course an old enough Windows, or plain DOS,
which allows you to do those operations.

Subsequently I moved all this to Linux. There is (was?) a tool -- fdparm? --
that you could use to tweak the floppy layout settings. A simple entry in its
config file would give the RX50 layout. Then it's just a matter of handling
the sector interleaving, track skew, and odd track numbering. With just a few
more lines of code, the application can handle the parameter setting so no
prior setup is needed, which is what I ended up doing in RSTSFLX (in C). The
latest version does this as well, but in Python.

So as far as I can see, all this stuff is perfectly easy if you just use a
plain ordinary floppy drive.

Hmmm.. I wonder if I could do any of this with my OS9 system
running on a Tandy COCO? Lot's of ability to fudge with disk
formats and you can't find a controller much older. :-)
Makes me wonder about the other old TRS80's. All handle 5.25
floppies and have old controllers. And OSes that let you do
pretty much anything you want. Even shoot yourself in the foot.

I wonder if I even have any RX50 floppies laying still around
here anywhere?

bill

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Paul Koning via cctalk

> On Feb 22, 2022, at 7:33 PM, Fred Cisin via cctalk  
> wrote:
> 
> From the FDC point of view, which doesn't have optical view of the drive and 
> media, the 80 track DD 5.25" looks similar to a "720K 3.5" drive.
> (80 tracks, 9 sectors per track, 300 RPM, 250K data transgfer rate)
> 
> On SOME PCs, setting the CMOS floppy setting to "720K" may take care of it.

Originally I wrote my RX50 floppies on a Windows PC.  The drive was a plain old 
5.25 inch PC drive, normally used for 9 sector per track PC floppies.  It turns 
out some BIOS operations will reset it to 10 sectors, which is RX50 format, and 
then BIOS int13 operations can read and write it.  I coded up support for that 
in RSTSFLX, which can be found on my Subversion server (in branches/V2.6).  The 
original version was built with Borland C++, but I switched to DJGPP which made 
all that much easier.  No CMOS or other magic needed, just an application that 
knows how to speak int13.  And of course an old enough Windows, or plain DOS, 
which allows you to do those operations.

Subsequently I moved all this to Linux.  There is (was?) a tool -- fdparm? -- 
that you could use to tweak the floppy layout settings.  A simple entry in its 
config file would give the RX50 layout.  Then it's just a matter of handling 
the sector interleaving, track skew, and odd track numbering.  With just a few 
more lines of code, the application can handle the parameter setting so no 
prior setup is needed, which is what I ended up doing in RSTSFLX (in C).  The 
latest version does this as well, but in Python.

So as far as I can see, all this stuff is perfectly easy if you just use a 
plain ordinary floppy drive.

paul

Re: Installing an operating system on the 11/83 - update.

A little over 40 years ago, while we were still using TRS80's at the 
college, the purchasing agent was sleeping with a vendor, and got us 
RoyType HD diskettes, instead of what we asked for (Verbatim Datalife).
When used in the TRS80s, it would format and write without showing errors, 
but minutes later, the disk was blank again!


Do NOT use HD diskettes to write DD formats!

(yes, on 3.5", you can use a high quality HD diskette to get a poor 
quality DD diskette, but on 5.25", you usually do NOT get away with it. 
Can you finish your use of the disk before it fades away?)

Re: Installing an operating system on the 11/83 - update.

From the FDC point of view, which doesn't have optical view of the drive 

and media, the 80 track DD 5.25" looks similar to a "720K 3.5" drive.
(80 tracks, 9 sectors per track, 300 RPM, 250K data transgfer rate)

On SOME PCs, setting the CMOS floppy setting to "720K" may take care of 
it.



On Tue, 22 Feb 2022, js--- via cctalk wrote:



On 2/22/2022 6:42 PM, Warner Losh wrote:


On Tue, Feb 22, 2022 at 4:36 PM js--- via cctalk > wrote:



Rod,

   Not sure an RX33 (if 1.2MB
equivalent) would write working RX50
800k (double density) disks.  Very
different drives.


The RX-33 is the same sort of drive that you had in your PC if you wrote
RX-50s with your PC. Back in the day, lots of people used RX50.SYS to
have it setup the transfer rates, RPM and sectors per track parameters
so that you could read/write them on a PC running DOS. The parameters
are basically the same ones you need to write the 360k DOS floppies, only
with twice the number of tracks and 10 sectors per track instead of 9 (this 
is

done by making the track gaps smaller and eeking an extra sector out of the
deal, but using at the same data rates).


Thanks for reminding me, Warner.  To recap:

The format used on a RX50 disk is:
Single Sided, 80 tracks, 10 sectors per track
96 TPI, 300 RPM, 250 KHz data rate
... which translates to 400K SSQD.

The format of a high density 5.25" PC disk is:
Double Sided, 80 tracks, 15 sectors per track
96 TPI, 360 RPM, 500 KHz data rate
... which translates to 1.2MB DSHD.

So to use an actual RX-50 on my PC, I just had to use an FDC capable of 
slowing down the data rate, and make a floppy cable to route the signals 
properly (minor changes from a PC floppy cable).


What Rod *might be* running up against with using PUTR and his RX-33, is that 
his RX-33 RPM and data rate might not be slowing down to equal that of the 
RX-50... which could be an FDC problem.Does the RX-33 automatically slow 
the RPM if the data rate drops to 250khz?


- John Singleton




   I've successfully put an actual
RX-50
drive on my PC, and written RX-50
images
using PUTR.  You might try that route.


Did you have difficulties with Pin34 not being the change disk pin? That's 
what

I ran into when I tried this many many years ago...

Warner

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Chuck Guzis via cctalk

On 2/22/22 16:12, js--- via cctalk wrote:

> As Chuck noted, I'd think you'd want to use 360K media -- not DSHD
> diskettes... and ensure that the 1.2MB drive is slowing down to 300RPM
> with a data rate of 250KHZ.
> 
> These features will depend on the 1.2MB drive you have, as well as your
> FDC and imaging software.

Use low-density media--the high-density stuff really requires higher
write currents (media is formulated for higher magnetic coercivity) to
work to spec.

Any PC that supports 1.2M 5.25" high-density media has a controller that
can vary the clock rate between 250, 300 and 500 Kbit/sec.  Clearly, if
you're using a garden-variety "1.2M" drive, you'd want to use the 300K
data rate, as those drives *generally* spin the disk at 360 RPM. (sort
of a mountain-Mohammed issue.   If you can't slow down the spindle
speed, boost the data rate).

There are several PC (MS-DOS) utilities that can handle this.  You
pretty much need the ones that do low-level controller access, as most
PC software assumes that low-density disks will double-step to get the
standard 48 tpi track spacing).

If you're bamboozled by any of this, drop me a line and I'll shoot you a
simple MSDOS utility that will write RX-50 disk formats on a standard PC.

--Chuck

Re: Installing an operating system on the 11/83 - update.


DD 5.25" disks are about 300 Oersted.
HD 5.25" disks are about 600 Oersted.

If you use HD disks to write DD content, the data fades away real fast.

However, on 3.5" disks, the difference is more like 600 Oersted VS 750 
Oersted, and you may get away with using the wrong disk.


360K disks are tested/certified for 40 track (48tpi) double density. 
Although not tested/certified for 80 track 96tpi, the cookie is the same, 
and they generally can handle 80 track (96tp) double density just fine. 
Disks of extremely marginal quality (such as Wabash, or pre-Datalife 
Verbatem) can still give you troubles.



In general, commercial 1.2M drives are also intended to be able to 
read/write(with track width problems!) 360K disks.  So, if the write 
current is at the "360K" level, and you get the data transfer rate correct 
(250K at 300RPM or 300K at 360RPM), and you get the drive to NOT "double 
step", then you can, indeed, read/write 80 track DD disks using a 1.2M 
drive.


Using a double density 80 track drive, such as the the Tandon TM100-4, 
Shugart/Panasonic/Matsushita 465, or the Teac 55F makes it a little 
simpler/easier, since those drives don't HAVE multiple write currents, nor 
360RPM, so just let the PC FDC think that it is a 360K drive (other than 
being 96tpi with 80 tracks), and the other issues aren't there.


10 512 byte sectors per track is similar to the 8 or 9 sector per track PC 
track format, other than squeezing an extra sector onto each track, by 
redducing the sector gaps.  Readily doable with INT13h (plus INT 1Eh), and 
not even having to talk directly to the FDC.


--
Grumpy Ol' Fred ci...@xenosoft.com

On Wed, 23 Feb 2022, Ray Jewhurst via cctalk wrote:


I read that you can indeed use a standard 1.2 Meg drive and that you can also 
use DSHD 5.25 disks in place of RX50s. Is there any truth in this? If there is 
it will be much easier and cheaper to make disks for my Rainbow.

Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android

Re: Installing an operating system on the 11/83 - update.




On 2/22/2022 7:00 PM, Ray Jewhurst wrote:
I read that you can indeed use a 
standard 1.2 Meg drive and that you 
can also use DSHD 5.25 disks in place 
of RX50s. Is there any truth in this? 
If there is it will be much easier and 
cheaper to make disks for my Rainbow.



As Chuck noted, I'd think you'd want to 
use 360K media -- not DSHD diskettes... 
and ensure that the 1.2MB drive is 
slowing down to 300RPM with a data rate 
of 250KHZ.


These features will depend on the 1.2MB 
drive you have, as well as your FDC and 
imaging software.


- John Singleton

Re: Installing an operating system on the 11/83 - update.

On Tue, Feb 22, 2022 at 5:01 PM Ray Jewhurst  wrote:

> I read that you can indeed use a standard 1.2 Meg drive and that you can
> also use DSHD 5.25 disks in place of RX50s. Is there any truth in this? If
> there is it will be much easier and cheaper to make disks for my Rainbow.
>

I'd avoid the HD diskettes, since they are designed for the recording rates
/ magnetic field densities of the 1.2 floppies. Some people have done it
successfully, though. Back in the day, there were many reports of people
doing this in their new AT or newer computers, but with a elevated error
rate... good enough for data transfer most of the time, but you'll
occasionally need to rewrite them.

I've successfully used DSDD disks in place of the now rather rare DSQD
disks. Based on long-term read back from disks I did this with in the 80s
and 90s, I'd say the retention is a bit worse, but if you are just making a
distribution set and reading it right away, you won't go far wrong. After
30 years, the failure rate was like 5%, back in the day it was closer to
1%, so I'd expect that now. It's what I did when I burned copies of the
Venix/86 disks to boot on my Rainbow... I've done it with both RX50.SYS and
a 1.2M drive on a DOS back years ago, and with a real RX-50 back in the
day, and just recently. Though come to think of it, all the disks were
formatted on my Rainbow under DOS with the hard format option

Warner

> Sent from my Verizon, Samsung Galaxy smartphone
> Get Outlook for Android <https://aka.ms/AAb9ysg>
> --
> *From:* cctalk  on behalf of Warner Losh
> via cctalk 
> *Sent:* Tuesday, February 22, 2022 6:42:38 PM
> *To:* j...@cimmeri.com ; General Discussion: On-Topic and
> Off-Topic Posts 
> *Cc:* gene...@ezwind.net 
> *Subject:* Re: Installing an operating system on the 11/83 - update.
>
> On Tue, Feb 22, 2022 at 4:36 PM js--- via cctalk 
> wrote:
>
> >
> > Rod,
> >
> >Not sure an RX33 (if 1.2MB
> > equivalent) would write working RX50
> > 800k (double density) disks.  Very
> > different drives.
> >
>
> The RX-33 is the same sort of drive that you had in your PC if you wrote
> RX-50s with your PC. Back in the day, lots of people used RX50.SYS to
> have it setup the transfer rates, RPM and sectors per track parameters
> so that you could read/write them on a PC running DOS. The parameters
> are basically the same ones you need to write the 360k DOS floppies, only
> with twice the number of tracks and 10 sectors per track instead of 9 (this
> is
> done by making the track gaps smaller and eeking an extra sector out of the
> deal, but using at the same data rates).
>
>
> >I've successfully put an actual RX-50
> > drive on my PC, and written RX-50 images
> > using PUTR.  You might try that route.
> >
>
> Did you have difficulties with Pin34 not being the change disk pin? That's
> what
> I ran into when I tried this many many years ago...
>
> Warner
>
>
> > - John Singleton
> >
> > On 2/22/2022 11:20 AM, Rod Smallwood via
> > cctalk wrote:
> > > Hi All
> > >
> > >   I did find some RX50 images of
> > > the MicroRSX distribution.
> > >
> > >  So I fired up my DEC Celebris FX.
> > > It runs W95 and has a 3.5 inch floppy,
> > > a real RX33 5.25 inch drive and a CD-R.
> > >
> > >Its accessible on my network so
> > > getting files onto it is not a problem.
> > >
> > > So install putR.com , and transfer
> > > the image files.
> > >
> > > Huh! putR says the RX50 disk is
> > > write protected. Its not and the drive
> > > works normally with the disk from the
> > > MS DOS prompt.
> > >
> > >  So much for putR writes RX50's on
> > > RX33!
> > >
> > > Rod
> > >
> > >
> > >
> > >
> >
>

Re: Installing an operating system on the 11/83 - update.




On 2/22/2022 6:42 PM, Warner Losh wrote:


On Tue, Feb 22, 2022 at 4:36 PM js--- 
via cctalk > wrote:



Rod,

   Not sure an RX33 (if 1.2MB
equivalent) would write working RX50
800k (double density) disks.  Very
different drives.


The RX-33 is the same sort of drive 
that you had in your PC if you wrote
RX-50s with your PC. Back in the day, 
lots of people used RX50.SYS to
have it setup the transfer rates, RPM 
and sectors per track parameters
so that you could read/write them on a 
PC running DOS. The parameters
are basically the same ones you need 
to write the 360k DOS floppies, only
with twice the number of tracks and 10 
sectors per track instead of 9 (this is
done by making the track gaps smaller 
and eeking an extra sector out of the

deal, but using at the same data rates).


Thanks for reminding me, Warner.  To recap:

The format used on a RX50 disk is:
Single Sided, 80 tracks, 10 sectors per 
track

96 TPI, 300 RPM, 250 KHz data rate
... which translates to 400K SSQD.

The format of a high density 5.25" PC 
disk is:
Double Sided, 80 tracks, 15 sectors per 
track

96 TPI, 360 RPM, 500 KHz data rate
... which translates to 1.2MB DSHD.

So to use an actual RX-50 on my PC, I 
just had to use an FDC capable of 
slowing down the data rate, and make a 
floppy cable to route the signals 
properly (minor changes from a PC floppy 
cable).


What Rod *might be* running up against 
with using PUTR and his RX-33, is that 
his RX-33 RPM and data rate might not be 
slowing down to equal that of the 
RX-50... which could be an FDC problem. 
   Does the RX-33 automatically slow 
the RPM if the data rate drops to 250khz?


- John Singleton




   I've successfully put an actual
RX-50
drive on my PC, and written RX-50
images
using PUTR.  You might try that route.


Did you have difficulties with Pin34 
not being the change disk pin? That's what
I ran into when I tried this many many 
years ago...


Warner

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Chuck Guzis via cctalk

On 2/22/22 15:33, js--- via cctalk wrote:
> 
> Rod,
> 
>   Not sure an RX33 (if 1.2MB equivalent) would write working RX50 800k
> (double density) disks.  Very different drives.

I've copied RX50 disks for a customer.  96 tpi 80 cylinder single-sided,
10 x 512 byte sectors.   You should be able to do this on a Windows PC
with a 1.2MB 5.25" drive and the appropriate utility, say, IMD.

The disks don't need the little red arrow stickers; use ordinary "360K"
media.

--Chuck

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Ray Jewhurst via cctalk

I read that you can indeed use a standard 1.2 Meg drive and that you can also 
use DSHD 5.25 disks in place of RX50s. Is there any truth in this? If there is 
it will be much easier and cheaper to make disks for my Rainbow.

Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android<https://aka.ms/AAb9ysg>

From: cctalk  on behalf of Warner Losh via 
cctalk 
Sent: Tuesday, February 22, 2022 6:42:38 PM
To: j...@cimmeri.com ; General Discussion: On-Topic and 
Off-Topic Posts 
Cc: gene...@ezwind.net 
Subject: Re: Installing an operating system on the 11/83 - update.

On Tue, Feb 22, 2022 at 4:36 PM js--- via cctalk 
wrote:

>
> Rod,
>
>Not sure an RX33 (if 1.2MB
> equivalent) would write working RX50
> 800k (double density) disks.  Very
> different drives.
>

The RX-33 is the same sort of drive that you had in your PC if you wrote
RX-50s with your PC. Back in the day, lots of people used RX50.SYS to
have it setup the transfer rates, RPM and sectors per track parameters
so that you could read/write them on a PC running DOS. The parameters
are basically the same ones you need to write the 360k DOS floppies, only
with twice the number of tracks and 10 sectors per track instead of 9 (this
is
done by making the track gaps smaller and eeking an extra sector out of the
deal, but using at the same data rates).

>I've successfully put an actual RX-50
> drive on my PC, and written RX-50 images
> using PUTR.  You might try that route.
>

Did you have difficulties with Pin34 not being the change disk pin? That's
what
I ran into when I tried this many many years ago...

Warner

> - John Singleton
>
> On 2/22/2022 11:20 AM, Rod Smallwood via
> cctalk wrote:
> > Hi All
> >
> >   I did find some RX50 images of
> > the MicroRSX distribution.
> >
> >  So I fired up my DEC Celebris FX.
> > It runs W95 and has a 3.5 inch floppy,
> > a real RX33 5.25 inch drive and a CD-R.
> >
> >Its accessible on my network so
> > getting files onto it is not a problem.
> >
> > So install putR.com , and transfer
> > the image files.
> >
> > Huh! putR says the RX50 disk is
> > write protected. Its not and the drive
> > works normally with the disk from the
> > MS DOS prompt.
> >
> >  So much for putR writes RX50's on
> > RX33!
> >
> > Rod
> >
> >
> >
> >
>

Re: Installing an operating system on the 11/83 - update.

On Tue, Feb 22, 2022 at 4:36 PM js--- via cctalk 
wrote:

>
> Rod,
>
>Not sure an RX33 (if 1.2MB
> equivalent) would write working RX50
> 800k (double density) disks.  Very
> different drives.
>

The RX-33 is the same sort of drive that you had in your PC if you wrote
RX-50s with your PC. Back in the day, lots of people used RX50.SYS to
have it setup the transfer rates, RPM and sectors per track parameters
so that you could read/write them on a PC running DOS. The parameters
are basically the same ones you need to write the 360k DOS floppies, only
with twice the number of tracks and 10 sectors per track instead of 9 (this
is
done by making the track gaps smaller and eeking an extra sector out of the
deal, but using at the same data rates).

>I've successfully put an actual RX-50
> drive on my PC, and written RX-50 images
> using PUTR.  You might try that route.
>

Did you have difficulties with Pin34 not being the change disk pin? That's
what
I ran into when I tried this many many years ago...

Warner

> - John Singleton
>
> On 2/22/2022 11:20 AM, Rod Smallwood via
> cctalk wrote:
> > Hi All
> >
> >   I did find some RX50 images of
> > the MicroRSX distribution.
> >
> >  So I fired up my DEC Celebris FX.
> > It runs W95 and has a 3.5 inch floppy,
> > a real RX33 5.25 inch drive and a CD-R.
> >
> >Its accessible on my network so
> > getting files onto it is not a problem.
> >
> > So install putR.com , and transfer
> > the image files.
> >
> > Huh! putR says the RX50 disk is
> > write protected. Its not and the drive
> > works normally with the disk from the
> > MS DOS prompt.
> >
> >  So much for putR writes RX50's on
> > RX33!
> >
> > Rod
> >
> >
> >
> >
>

Re: Installing an operating system on the 11/83 - update.




On 2/22/2022 11:20 AM, Rod Smallwood via 
cctalk wrote:

Hi All

  I did find some RX50 images of 
the MicroRSX distribution.
 So I fired up my DEC Celebris FX. 
It runs W95 and has a 3.5 inch floppy, 
a real RX33 5.25 inch drive and a CD-R.
   Its accessible on my network so 
getting files onto it is not a problem.
So install putR.com , and transfer 
the image files.
Huh! putR says the RX50 disk is 
write protected. Its not and the drive 
works normally with the disk from the 
MS DOS prompt.
 So much for putR writes RX50's on 
RX33!


Rod



Rod,

  Not sure an RX33 (if 1.2MB 
equivalent) would write working RX50 
800k (double density) disks.  Very 
different drives.


  I've successfully put an actual RX-50 
drive on my PC, and written RX-50 images 
using PUTR.  You might try that route.


- John Singleton

Re: Installing an operating system on the 11/83 - update.




Rod,

  Not sure an RX33 (if 1.2MB 
equivalent) would write working RX50 
800k (double density) disks.  Very 
different drives.


  I've successfully put an actual RX-50 
drive on my PC, and written RX-50 images 
using PUTR.  You might try that route.


- John Singleton

On 2/22/2022 11:20 AM, Rod Smallwood via 
cctalk wrote:

Hi All

  I did find some RX50 images of 
the MicroRSX distribution.


 So I fired up my DEC Celebris FX. 
It runs W95 and has a 3.5 inch floppy, 
a real RX33 5.25 inch drive and a CD-R.


   Its accessible on my network so 
getting files onto it is not a problem.


So install putR.com , and transfer 
the image files.


Huh! putR says the RX50 disk is 
write protected. Its not and the drive 
works normally with the disk from the 
MS DOS prompt.


 So much for putR writes RX50's on 
RX33!


Rod

Re: Installing an operating system on the 11/83 - update.

On Tue, Feb 22, 2022 at 3:24 PM Rod Smallwood via cctalk <
cctalk@classiccmp.org> wrote:

>
> On 22/02/2022 16:20, Rod Smallwood via cctalk wrote:
> > Hi All
> >
> >   I did find some RX50 images of the MicroRSX distribution.
> >
> >  So I fired up my DEC Celebris FX. It runs W95 and has a 3.5 inch
> > floppy, a real RX33 5.25 inch drive and a CD-R.
> >
> >Its accessible on my network so getting files onto it is not a
> > problem.
> >
> > So install putR.com , and transfer the image files.
> >
> > Huh! putR says the RX50 disk is write protected. Its not and the
> > drive works normally with the disk from the MS DOS prompt.
> >
> >  So much for putR writes RX50's on RX33!
> >
> > Rod
> >
> >
> So to sum up I have yet to find a tried and tested way to write a RX50
> disk image to an RX50 disk on a W95 PC with a 5.25 inch drive.
>

Are you using RX50.SYS? And properly formatted media?

Warner

Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Rod Smallwood via cctalk




On 22/02/2022 16:20, Rod Smallwood via cctalk wrote:

Hi All

  I did find some RX50 images of the MicroRSX distribution.

 So I fired up my DEC Celebris FX. It runs W95 and has a 3.5 inch 
floppy, a real RX33 5.25 inch drive and a CD-R.


   Its accessible on my network so getting files onto it is not a 
problem.


    So install putR.com , and transfer the image files.

    Huh! putR says the RX50 disk is write protected. Its not and the 
drive works normally with the disk from the MS DOS prompt.


     So much for putR writes RX50's on RX33!

    Rod


So to sum up I have yet to find a tried and tested way to write a RX50 
disk image to an RX50 disk on a W95 PC with a 5.25 inch drive.


Rod

Re: Greasweasel was Re: Installing an operating system on the 11/83 - update.

2022-02-22 Thread Jay Jaeger via cctalk


On 2/22/2022 12:29 PM, Ray Jewhurst via cctalk wrote:

I was wondering how well a Greaseweasel would write floppies for my Rainbow. 
Also, I saw that someone had images for Venix-86 Rainbow and I was wondering if 
they would be interested in sharing them.

Thanks
Ray

Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android



I was certainly able to *read* them on my Greaseweazle, using a real 
RX50 drive, and compared them to images I had read earlier under MS-DOS 
with a driver on a 360K drive.  I see no reason offhand why they could 
not be written with a Greaseweazle as well, unless the actual sector 
encoding (as opposed to sector size) is weird - and I don't recall that 
it is.  BTW, I used a Greaseweazle to write some IBM DD floppies for 
someone with a System/36 (IIRC) using a DSDD drive I borrowed from my DG 
S/140, and they worked fine for him.


JRJ

Re: Greasweasel was Re: Installing an operating system on the 11/83 - update.