Re: CP/M-85 ??

On Nov 2, 8:12 pm, no.s...@xxxxxxxxxxxxxxxxxxxxxxx wrote:
On Fri, 02 Nov 2007 11:47:31 -0700, Herb Johnson

<herbrjohn...@xxxxxxxxx> wrote:
On Nov 2, 4:09 am, MikeS <dm...@xxxxxxxxxxx> wrote:

Well, yes, I am talking about the M100 & M102 although the M200 would
be better due to its larger screen. But you haven't been keeping up
with developments in that world, Allison; I did say it had expanded
memory: there are internal expansion modules available now for <$100
that give you (for example) 2MB of RAM, 2x2MB of Flash ROM and a 256K
RAMPAC for storage...

Model 100';s are fun to play with. It's hard to search the Web for
"model 100" or "TRS-80" without a lot of false hits. Do you have Web
links to specific sites which offer these modules? Even "club 100"
does not apparently offer them. And, has anyone ported CP/M for use

I have all the good sites bookmarked and when I checked one had
even gone away I find nothing that sounds like the modules.

with this memory? (The 100 did run CP/M with an external drive I
believe?)

No it ran somthing married to the MS basic.

I suspect comp.sys.tandy has more discussion of the Model 100. But
most of the time when it's mentioned there, there's a post which says
"go to the club 100 site".

The basic answer still stands, 8085 runs CP/M, yes.

Some aps _require_ Z80. Not a terrible limitation but known.

CP/M to be useful to run aps of value and interest needs 48K+
of contigious ram starting at 0000h

M10x have 32k of rom at 0000. That's not an advantagous memory map
for useful flavors of available CP/M applications.

All the extended mapped ram in the world makes only for a ramdisk.
The addressing of 8085 is a flat 64k, any rom in that space means
the useful space is smaller.

You don't port CP/M, you write a BIOS to match the OS to the local
device environment. In the case of M10x that means an LCD driver,
keyboard driver, and someform of disk (ramdisk, romdisk floppy, CF
MMC or even mag tape).

The Epson PX8 is a Z80 that has CP/M in it with rom mapping
for ROMdisk , RAMdisk and floppy, and micromagtape.
Works good.

Allison





Herb Johnson
retrotechnology.com

Herbert R. Johnson, New Jersey USA
http://www.retrotechnology.com/herbs_stuff/ web site
http://www.retrotechnology.net/herbs_stuff/ domain mirror
my email address: hjohnson AAT retrotechnology DOTT com
if no reply, try in a few days: herbjohnson ATT comcast DOTT net
"Herb's Stuff": old Mac, SGI, 8-inch floppy drives
S-100 IMSAI Altair computers, docs, by "Dr. S-100"- Hide quoted text -

- Show quoted text -

Aaargghh...

Allison, you keep talking about the limitation of the 32K ROM;
apparently you missed the part where I said that there is no ROM in
this configuration. As you probably know, even the stock Mxxx has a
mechanism for switching out the normal 32K ROM and replacing it with
one of the many option ROMs available and it's a fairly simple hack to
replace that with RAM, giving you 64K of RAM (which you can then load
from the ROM or the high RAM).

The modules I mentioned give you several MB of RAM and Flash memory
and you can pretty well switch in whichever ROM image (and/or RAM)
that you want (although I don't know what the bank switch granularity
options are right now). They're built by one of the members of Club100
up here in Canada, and several other members are looking after the
software support.

See:
http://www.bitchin100.com/
Remem and REX memory upgrades

So what does "porting" mean if it doesn't include modifying (i.e.
[re]writing the BIOS for) an existing OS to run on a new machine?
Guess I've been misusing the term, since I'd call every different
implementation of the original CP/M a port of the MDS-800 version.

And Herb:
Apparently you're guilty of misusage too, and no, AFAIK CP/M has not
been "ported" to an Mxxx; that's why I'm asking!

mike

.

Relevant Pages

  • Re: CP/M-85 ??
    ... The basic answer still stands, 8085 runs CP/M, yes. ... M10x have 32k of rom at 0000. ... All the extended mapped ram in the world makes only for a ramdisk. ... disk and housekeeping ...
    (comp.os.cpm)
  • Re: Looking for simple OS for Z80, romable
    ... A familiar approach, BTDT, however CP/M at ... Rom 8k or larger and forget boot tracks saves startup stuff. ... As long as the BDOS ... Swapped out ram is 64k, swapped in the lost 32k is rom. ...
    (comp.os.cpm)
  • Re: OTF Encryption? Basic PPC2003 se security questions? (newbie)
    ... > since rom files can be displaced by replacement files. ... This suggests that the loader looks at a "replacement" folder before ... > added programs can be loaded into ram or memory cards, ... > hard reset the device which erases all ram content. ...
    (microsoft.public.pocketpc)
  • Re: CP/M-85 ??
    ... the rom, map in a boot rom then map in ram and uses CF as disk ... I have put CP/M on the M100 and a few other 8085 powered ... found on the 'net and store them on local disk so long as you have ...
    (comp.os.cpm)
  • Re: Difference between ROM and RAM
    ... to configure their memory the way they want would be good. ... Finally, if you code for a requirement of 128MB of RAM, you'll really limit ... RAM and ROM up until ... I'm programming application for Pocket PC and I'm ...
    (microsoft.public.pocketpc)