Montezuma Micro hard disk support?
Mike Loewen
Model 4. My system never had a hard disk attached, only 2 floppy drives.
It still runs, for that matter. :-)
Was there ever hard disk support for Montezuma Micro CP/M? The last
version I had was BIOS version 2.22, and the manual only mentioned the
possibility of hard disk support in the future.
I've used a couple of the current TRS-80 emulators, notably Tim Mann's
xtrs-3.8 and David Keil's emulator version 5.11. Both provide hard disk
support for the Model 4, but apparently only in LDOS/TRSDOS mode. There's
also an image of Montezuma Micro CP/M 2.30 floating around in DSK format,
but it doesn't seem to have hard drive support, either.
So, could the historians enlighten me? I've been toying with the idea
of adding a hard drive to my physical Model 4, but it would also be nice to
see hard drive support in the emulators with CP/M.
--
Mike Loewen Center for Academic Computing
Email: mc...@psu.edu The Pennsylvania State University
Phone: (814) 863-4356 University Park, PA 16802
Office: 17 Willard Bldg. http://ripsaw.cac.psu.edu/mloewen.html
Tim Mann
when writing xtrs's hard disk emulation. Instead of emulating real hardware,
as the rest of xtrs does, I wrote a special driver in Z-80 code that uses
xtrs's emulator traps (instruction set extensions) to access a file on
the host system as if it were a hard disk. This driver will of course
work only with LDOS/LSDOS. David Keil's emulator is the same; he implemented
the same emulator traps and uses my driver.
It probably wouldn't be too hard to emulate the real hardware for one of
the popular Model 4 hard disks (say, Tandy's), but I don't plan to do it
unless there is a good reason to.
Another option would be to modify the LDOS driver for use with CP/M.
Knowing little about CP/M, I have no idea how hard disk drivers plug into
it, or even *if* there is a standard way to plug them in. Is this specific
to each BIOS implementation, perhaps?
--Tim
> From: mlo...@cac.psu.edu (Mike Loewen)
> -----
> I used to run Montezuma Micro CP/M almost exclusively on my TRS-80
> Model 4. My system never had a hard disk attached, only 2 floppy drives.
> It still runs, for that matter. :-)
>
> Was there ever hard disk support for Montezuma Micro CP/M? The last
> version I had was BIOS version 2.22, and the manual only mentioned the
> possibility of hard disk support in the future.
>
> I've used a couple of the current TRS-80 emulators, notably Tim Mann's
> xtrs-3.8 and David Keil's emulator version 5.11. Both provide hard disk
> support for the Model 4, but apparently only in LDOS/TRSDOS mode. There's
> also an image of Montezuma Micro CP/M 2.30 floating around in DSK format,
> but it doesn't seem to have hard drive support, either.
>
> So, could the historians enlighten me? I've been toying with the idea
> of adding a hard drive to my physical Model 4, but it would also be nice to
> see hard drive support in the emulators with CP/M.
Tim Mann <ma...@pa.dec.com> Compaq Systems Research Center
http://www.research.digital.com/SRC/personal/Tim_Mann/
Dan Srebnick
drivers on my model 4.
Dan Srebnick
On Sat, 21 Aug 1999, Mike Loewen wrote:
> In article <7pmj1h$16k$1...@ears.islenet.com> you write:
> >There were HD drivers for MM CP/M 2.2. I purchased and have used them
> >drivers on my model 4.
>
> Are these drivers still available anywhere for MM? The OS itself seems
> to be freely downloadable in DSK format, but I've never run across the
> drivers.
O. Alan Jones
The guys at comp.os.cpm can probably answer your question.
--Alan
Mike Loewen wrote:
> I used to run Montezuma Micro CP/M almost exclusively on my TRS-80
> Model 4. My system never had a hard disk attached, only 2 floppy drives.
> It still runs, for that matter. :-)
>
> Was there ever hard disk support for Montezuma Micro CP/M? The last
> version I had was BIOS version 2.22, and the manual only mentioned the
> possibility of hard disk support in the future.
>
> I've used a couple of the current TRS-80 emulators, notably Tim Mann's
> xtrs-3.8 and David Keil's emulator version 5.11. Both provide hard disk
> support for the Model 4, but apparently only in LDOS/TRSDOS mode. There's
> also an image of Montezuma Micro CP/M 2.30 floating around in DSK format,
> but it doesn't seem to have hard drive support, either.
>
> So, could the historians enlighten me? I've been toying with the idea
> of adding a hard drive to my physical Model 4, but it would also be nice to
> see hard drive support in the emulators with CP/M.
>
Roland Gerlach
> There were HD drivers for MM CP/M 2.2. I purchased and have used
> them drivers on my model 4.
I too think it would be fantastic to have hard disk support for
Montezuma CP/M in an emulator.
I have considered writing a driver that "cheats" like Tim Mann
described but I don't know enough about CP/M to get a driver to
integrate with the BDOS & BIOS.
I can still remember the headaches I had trying to get Montezuma CP/M
to read a native Microbee CP/M floppy disk and all I had to do was to
obtain the right disk parameters.
Besides, investing that much effort into understanding the BDOS & BIOS
of CP/M now seams to be a bit of a waste when you think about all the
cutting edge computer software out there now.
But if we have a real driver as the starting point ......
Did you have a Hard Disk for your model 4? How did you receive the
drivers? Was it a new version of CP/M or was it just a program you
had to run? How did you install the drivers? Obviously the hard disk
partitions just used up additional drive letters but how were the
letters assigned? There are probably many more questions to ask - can
you tell us more about the drivers?
Cheers,
Roland.
--
Tell me and I'll forget; show me and I may remember;
involve me and I'll understand - Chinese Proverb.
Mike Loewen
Roland Gerlach <rol...@rkga.com.au> wrote:
>
>Did you have a Hard Disk for your model 4? How did you receive the
>drivers? Was it a new version of CP/M or was it just a program you
>had to run? How did you install the drivers? Obviously the hard disk
>partitions just used up additional drive letters but how were the
>letters assigned? There are probably many more questions to ask - can
>you tell us more about the drivers?
Perhaps someone with the hard disk driver for MM could donate it to the
cause, so one of us could disassamble it?
Mark P. Fishman
Hard drive support under CP/M was specific to both the BIOS implementation
and to the hard drive hardware (as you would expect). The BIOS allocated
space for things like blocking and deblocking of drive sectors or
allocation units, because the rest of CP/M assumed 128-byte blocks.
Montezuma Micro offered installable hard-disk drivers for Tandy drives as
well as for their own SCSI-based drives. They loaded at the top of memory,
which required using the CP/M tools to resize the system before
installation. They were loaded on-the-fly by a command line at each boot.
I bought and have copies of MM's HD drivers for their 30MB SCSI system and
for the 15MB Tandy drive. The drivers are hard-coded for those size
drives, although it shouldn't be hard to patch them for other sizes.
Cheers -- Mark F.
On 21 Aug 1999, Tim Mann wrote:
> I'd like to know the answer to Mike's question below too. I "cheated"
> when writing xtrs's hard disk emulation.
> It probably wouldn't be too hard to emulate the real hardware for one of
> the popular Model 4 hard disks (say, Tandy's), but I don't plan to do it
> unless there is a good reason to.
>
> Another option would be to modify the LDOS driver for use with CP/M.
> Knowing little about CP/M, I have no idea how hard disk drivers plug into
> it, or even *if* there is a standard way to plug them in. Is this specific
> to each BIOS implementation, perhaps?
--
reply to: mfishman at alum dot em eye tee dot ee dee ewe
Clarence Wilkerson
interface, the driver code is probably not so bad.
The advantage of the SASI/SCSI interface is that you don't
have to deal with nitty-gritty timing details as with a
floppy. Of course, somebody else had to sweat to produce
the firmware for the controller!
For examples of a nice top approach to such drives, look at
the "last" H89 bios at
http://www.math.purdue.edu/~wilker/misc/cpm/bios
I've used this with a DTC510 controller, and with minor
mods, WD and Xebec.
Good luck.
--
Clarence Wilkerson \ HomePage: http://www.math.purdue.edu/~wilker
Prof. of Math. \ Internet: wil...@NOspam.math.purdue.edu
Dept. of Mathematics \ Messages: (765) 494-1903, FAX 494-0548
Purdue University, \
W. Lafayette, IN 47907-1395 \
David Keil
support for hard drives. I prefer Montezuma Micro's CP/M though. If any one
knows enough about writing a CP/M to write a hard drive driver I will make
whatever changes to my emulator that are required to enable it to work. I
will help in any way I can.
Also if anyone has technical specs for the RS hard drives I could write a
hardware level emulation so the Radio Shack drivers would work.
The better solution however is to write a CP/M driver that uses software
traps. This makes the driver much smaller and faster since to the TRS-80 the
sector data just appears like magic without the byte by byte transfer
required by true hardware emulation.
--
David
dmk...@discover-net.net
http://discover-net.net/~dmkeil/