California Digital still offers original boxed DR CP/M for $15 at
http://www.cadigital.com/software.htm
Bob
Original Message:
Message: 12
Date: Thu, 28 Jul 2005 14:52:57 -0400
From: Roger Merchberger <zmerch at 30below.com>
Subject: If yer lookin' for CP/M...
To: cctalk at classiccmp.org
Message-ID: <5.1.0.14.2.20050728144501.03a67ab0 at mail.30below.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed
Stumbling across some of the links previously provided for the different
permutations of DR-DOS, I found this:
ftp://ftp.fsn.hu/pub/OpenDOS/cpm2.2/
Caldera at one point acquired some form of CP/M, and this appears to be a
CP/M 2.2 for a Z80, if the filenames are any indication.
HTH,
Roger "Merch" Merchberger
>
>Subject: Re: DEC Rainbow disks - help
> From: Paul Koning <pkoning at equallogic.com>
> Date: Fri, 29 Jul 2005 09:14:35 -0400
> To: cctalk at classiccmp.org
>
>>>>>> "Allison" == Allison <ajp166 at bellatlantic.net> writes:
>
> >> ...
> >> Ok, so where physically is LBA 0? On most disks it is cyl 0 track
> >> 0 sec 0. But not on the RX50; there it is cyl 1 track 0 sec 0.
> >>
> >> So what LBA lives on cyl 0 track 0 sec 0? Answer: I'm getting too
> >> confused in the arithmetic, but it's an LBA in the range 790 to
> >> 799.
>
> Allison> snipped...
>
> Allison> OK, that applies to NON CP/M and DOS disks and I can see how
> Allison> it would be a PITA to create DOS or CP/M media from other
> Allison> DEC systems. Having done it in the past those memory bits
> Allison> were lost. ;) Mostly due to trying to do the reverse (DEC
> Allison> OSs from CP/M hardware).
>
> Allison> I see no other impact to the Rainbow from the RX50.
>
>I don't actually know the Rainbow, but I have a bit of code elsewhere
>that contains this comment:
>
>/* Convert block number to cylinder, head, sector for RT11-RX50.
> * This is different for RT11 than for Rainbow DOS:
> * For DOS, for cylinders 2 through 79, the sectors are interleaved 2:1.
> * (DOS capability is not supported in this RT11 version).
> * For RT11, all sectors are interleaved 2:1, and each subsequent
> * track has the first logical block offset by 2 more sectors.
> */
>
>So the implication is that Rainbow RX50s are still weird, but weird
>differently than PDP11 ones. I don't have more detail than that, and
>I don't remember the origin of that comment.
>
> paul
No, the dos disk are structured not unlike the CP/M disks where the first
track(cylinder) is system area (loads a loader from there). They are
weird compared to nominal PC but in the CP/M system world they are
not so strange.
FYI: some CP/M systems did not use interleave (skew) at the bios level
and instead wrote the cylinders with non sequential (skewed) sector
numbers. The effect is the same but required less code to get skewing.
Ths was especially handy when 512byte sectors were used
(4 logical cpm sectors).
Allison
>
>Subject: Re: DEC Rainbow disks - help
> From: Jules Richardson <julesrichardsonuk at yahoo.co.uk>
> Date: Fri, 29 Jul 2005 15:28:06 +0000
> To: cctalk at classiccmp.org
>
>On Fri, 2005-07-29 at 09:14 -0400, Paul Koning wrote:
>> I don't actually know the Rainbow, but I have a bit of code elsewhere
>> that contains this comment:
>>
>> /* Convert block number to cylinder, head, sector for RT11-RX50.
>> * This is different for RT11 than for Rainbow DOS:
>> * For DOS, for cylinders 2 through 79, the sectors are interleaved 2:1.
>> * (DOS capability is not supported in this RT11 version).
>> * For RT11, all sectors are interleaved 2:1, and each subsequent
>> * track has the first logical block offset by 2 more sectors.
>> */
>>
>> So the implication is that Rainbow RX50s are still weird, but weird
>> differently than PDP11 ones. I don't have more detail than that, and
>> I don't remember the origin of that comment.
>
>Strange how they don't interleave the first couple of cylinders for the
>Rainbow. Why is that? It there some situation where it's necessary to
>write some form of boot sectors on the disk in order?
Those are reserved for "system" tracks and are not part of the data area.
>For RT11 it sounds like there are issues with the hardware finding the
>index hole and being able to react in time to read the first sector on
>the track, hence the offset within the track to the first logical block
>on that track?
No. RT11 has no such problem. It's possible the controller could but, that
is not true either. The index hole and all are invisible to the OS as it's
all a controller problem.
Allison
----- Original Message -----
> On 7/27/05, gordonjcp at gjcp.net <gordonjcp at gjcp.net> wrote:
> > You can't open the lid, unless you open a little hatch on the
> right-hand side and trip the catch by hand.
>
> If that unit has one. The little hatch does not appear on all drives.
Everything's fine. Pack is out, heads are secured, a 4 lb hammer was plenty big enough :)
It should be on the way.
Now, can someone tell me what to do when it arrives? Something like, check the filters, run for a while with the heads locked to purge dust, etc. Any good source for a new filter?
thanks
Charles
Hi there Curt
My name is Michael from Melbourne Australia, a Musician
that has always loved ataris for Midi work and still using mine
today.
I am not sure if I have the right person or Not, I am chasing a Curt that posted
a Message on one of the Developer sites with regards to Atari UNIX Disk images
" For those who own Atari TT030 workstations, I have finally gotten a
hard disk with Atari's version of Unix System V on it running along with a
diskette with setboot.prg utility that sets the nvram in the TT030's to
recognize and boot from the Unix Hard Disk.
If anyone is interested, I can make ghost images of the 300MB SCSI
hard disk
If you want a copy, I need a 300mb SCSI HD to Ghost the image to and
you pay shipping to and from me.
Curt
If you are the person that did submit this back late last year? does your offer
of the disk images still stand.
Kind regards
Michael Sims
m_sims at iprimus.com.au
" Home Email Address"
Just got a call from a guy at a local high-school that's doing some cleaning, and they're apparently getting ready to dumpster a bunch of Apple IIe's. He says he can probably save some for me, and maybe the monitors to go with them, if I let him know soon. I'm probably going to grab a couple for myself; would anyone else like one for the cost of packing and shipping? Let me know ASAP.
P.S. - Shipping would be from Nebraska.
>Strange how they don't interleave the first couple of cylinders for the
>Rainbow. Why is that? It there some situation where it's necessary to
>write some form of boot sectors on the disk in order?
Assuming this is a hardware interleave (ie: physically different sector
number ordering on the track):
The loader is typically loaded "raw fast" by the boot, which is simply
reading the sectors into memory, so once one is done, it can be
immediately ready for the next one. It may therefore speed up the boot
process slightly to put these sectors with 1:1 interleave.
The remainder of the disk is "application area" and the amount of
processing required between sectors is indeterminate, but you can
be fairly sure that most of the time there will be some gap between
sector requests, so it makes sense to interleave these.
If it's software interleave (like CP/M does with it's XLT table), then
the reason may be more basic - the loader may not include enough smarts
to perform the local to physical sector translation, hence boot tracks
have logical=physical.
I doubt that interleave will affect the functionality of either area
other than speed.
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: DEC Rainbow disks - help
> From: Paul Koning <pkoning at equallogic.com>
> Date: Thu, 28 Jul 2005 17:42:48 -0400
> To: cctalk at classiccmp.org
>
>>>>>> "Allison" == Allison <ajp166 at bellatlantic.net> writes:
>
> >> The other confusing point is the addressing: logical block 0 is at
> >> the start of track 1, the sectors are 2:1 interleaved, and
> >> physical track 0 holds the LAST 10 logical sectors...
>
> Allison> ???? CP/M disks nominally start logical block 0 after
> Allison> system tracks. Dos disk are different and I never paid much
> Allison> attention to them. POS for the PRO was same media but file
> Allison> allocation was different again from CP/M or DOS [or RT11 and
> Allison> VMS as well] on RX50.
>
>I'm not talking about the file system, I'm talking about block
>numbering -- the linear block numbers (0 to 799) which sit underneath
>the file systems. All the DEC PDP11 and VAX OSs use linear block
>addressing; the sector/track/cylinder structure of the drives exists
>below the file system only, and is mapped to LBA by the disk device
>driver.
>
>For example, on all disks, LBA 0 is the boot block.
>
>Ok, so where physically is LBA 0? On most disks it is cyl 0 track 0
>sec 0. But not on the RX50; there it is cyl 1 track 0 sec 0.
>
>So what LBA lives on cyl 0 track 0 sec 0? Answer: I'm getting too
>confused in the arithmetic, but it's an LBA in the range 790 to 799.
snipped...
OK, that applies to NON CP/M and DOS disks and I can see how it would be
a PITA to create DOS or CP/M media from other DEC systems. Having done
it in the past those memory bits were lost. ;) Mostly due to trying to
do the reverse (DEC OSs from CP/M hardware).
I see no other impact to the Rainbow from the RX50.
Allison
