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Osborne 1 <--> PC over RS232

giobbi

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I looked up the Osborne tech manual and realized how bad the design was:

The floppies get power over the data cable - That's +5 and +12. So to swap drives you would have to make a modified 34 pin cable. That is to say the +5 and +12 volt lines cut or at least just left out of drive connector and those lines soldered to a standard floppy power cable.

The I/O is memory mapped in bank switched memory so any I/O requires calls to common memory where the I/O port is swapped in before it is read or written to then memory is swapped back to TPA bank.

Both a pain in the ass and a fantastic way to really slow down I/O.

I haven't had time to pull out my Turbo Pascal to write a load program. It would probably be easier to create disks with software on it and mail it to you.

I know that customs would slow it down but you would get more.

Let my know if you have any trouble with the modem software sent to you - If so I will just make a small stack of useful disks to send you.

Ok Randy, thank you; I believe the first floppy will be here in few days, customs already processed the parcel.

About FDD: yes, they are different from normal, PC standard, FDD ones.
 

Randy McLaughlin

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Ok Randy, thank you; I believe the first floppy will be here in few days, customs already processed the parcel.

About FDD: yes, they are different from normal, PC standard, FDD ones.

Being different basically means try to keep. But if worst came to worst it means a modified cable would be needed to use a standard drive.


Randy
 

giobbi

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I sent a disk, unknown time to Brazil. I'm pretty sure it's SD. MDM740

Ok, I got the disk today and yes, it's SSSD; thank you for that!

So I tried to connect a DOS PC and the Osborne 1 together, but I had some troubles...


I tried a simple terminal mode, using Qmodem on the DOS side and MDM740 on the Osborne side.
On the Osborne I entered the Terminal mode typing the "T" command (but I tried the "E" command too, same result).

In short: what I type is not what appears on screen on the other side: i.e. when I type a key on the Osborne, I get three or four ascii chars on the PC.
Of course the X-Modem (called Christensen Protocol in the mdm740 guide, I didn't know that, LOL) doesn't work: it doesn't start.


The serial ports and cable are working, at least partially:
I can transfer an ascii file from PC to Osborne using Qmodem -> ascii upload (DOS) and PIP file.txt=RDR: (CP/M). NOTE: On Osborne I must to enter the diagnostic tool, run the serial port test, and press Enter twice ON THE DOS PC to "open"; It returns TEST FAIL at both speeds (300 and 1200) but when I exit the diagnostic tool and use the PIP command it work.
PIP transfer doesn't work if I don't run the diagnostic tool before.

I can't transfer a file from Osborne to DOS using PIP CON:=file.txt or PIP PUN:=file.txt (note that both CON: and PUN: are assigned to TTY:).


I'm using a straight cable, since the cross one doesn't work at all. I tried two DOS PCs, same behavior.

Any idea?
 

giobbi

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I did some steps ahead...

I found that you must to enter in Qmodem and MDM740 and *then* connect the cable. This way, the terminal mode works.

Now I'm trying to transfer files from Osborne to PC.
In Qmodem I have some choices about XModem:

Xmodem
CRC Xmodem
Xmodem Relaxed
Xmodem-1K
Xmodem 1K/G

none of them seems to work. I get two different error messages, depending on the Xmodem type I choose:

TIMEOUT - no ACK
NAK received not ACK

Any idea?
 

Randy McLaughlin

Experienced Member
Joined
Jun 6, 2016
Messages
99
I did some steps ahead...

I found that you must to enter in Qmodem and MDM740 and *then* connect the cable. This way, the terminal mode works.

Now I'm trying to transfer files from Osborne to PC.
In Qmodem I have some choices about XModem:

Xmodem
CRC Xmodem
Xmodem Relaxed
Xmodem-1K
Xmodem 1K/G

none of them seems to work. I get two different error messages, depending on the Xmodem type I choose:

TIMEOUT - no ACK
NAK received not ACK

Any idea?
It sounds like you have the wrong baud rate. Getting anything is good - even if it's garbage.

Just try a lower baud-rate on the PC side - I think it defaults to either 300 or 1200 baud.

Just keep typing on the Osborne side and adjusting baud rate on PC side.

You can make sure the Osborne serial port is good by disconnecting the cable and shorting pins 2 and 3 together. Then anything type on the keyboard should echo back to screen.


Randy
 

phogren

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Morro Bay, CA
I agree on the baud rate. Try at 300 baud and increase later.
Remember that you don't need a null modem cable since the Osborne serial port is configured for a printer.

I'll fire up my Osborne if you are still not having any luck.

I would suspect a possible problem on the PC side.

If you can check between the PC and another computer to rule out any possible problems with the PC. Remembering that you might need a null-modem cable with a standard PC.
 

ldkraemer

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Don't forget that the MDM740 program has the SET command:

SET - Set modem baud rate

and COMMAND: ? <RET>

Shows current settings.

and TCC - Toggle CRC/Checksum mode on receive



Larry
 

giobbi

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ok, it seems the COM port of my XT clone has some problem; I didn't noticed before that Qmodem is toggling ONLINE/OFFLINE quickly (monochrome monitor and low contrast on text...).

I tried with a WinME PC adjusting both computers at 300 baud, and finally I can transfer files (I didn't remember how slow is 300 baud, how did we download file from BBS at that speed??? LOL)

Tomorrow I will try to raise the speed, now it's 1.00 AM and I'm almost sleeping...

Thank you for now!

--Giovi
 

Randy McLaughlin

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Messages
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ok, it seems the COM port of my XT clone has some problem; I didn't noticed before that Qmodem is toggling ONLINE/OFFLINE quickly (monochrome monitor and low contrast on text...).

I tried with a WinME PC adjusting both computers at 300 baud, and finally I can transfer files (I didn't remember how slow is 300 baud, how did we download file from BBS at that speed??? LOL)

Tomorrow I will try to raise the speed, now it's 1.00 AM and I'm almost sleeping...

Thank you for now!

--Giovi

Fantastic and congrats.

Without modifying the Osborne you can run either 300 or 1200 baud, since you have 80K of space per disk 1200 baud will fill it up fast enough ;-)

1200 baud can fill an 80K disk in less than 12 minutes. But you can modify the baud rate generator as described in the technical manual:

http://history-computer.com/Library/Osborne1TechnicalManual.pdf

One limit to speed is the serial port access is complicated and has a decent overhead in processing.


Randy
 

giobbi

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Thank you guys for the help. As usual, without your help I couldn't resolve. This forum is terrific! :)

For some reason, the problems I had yesterday seem to be vanished today and it works flawless at 1200 baud. Boooh.

---------------

So, after some test, I decided to transfer some files I got from the web to floppy SSSD by serial port.
Of course nothing is easy... I'm trying to extract some files from image files (.IMD, .TD0 and .LBR from the FOG archive), without success.

I tried cmptools, no luck. Also 22disk, dsktool and teledisk didn't help a lot.... and I can't find useful infos on Google.

I found this page that seemed promisingly: http://forums.debian.net/viewtopic.php?f=16&t=112244 but I have to admit I found it very complicated.

I'm wondering if anybody wrote an easy tool (GUI?) or some easy step-by-step instruction about how to manipulate and/or extract files from a disk image, or put files on it...
I mean: there's plenty of cpm disk image on the web... nobody felt the need to have a tool like this before?

Admitting there's an easy way to do that, any help or "dummy proof" guide about how to extract files from these three format (.IMD, .TD0 AND .LBR) would be very appreciated!


--Giovi
 

ldkraemer

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Giovi,
What are the filenames for the .IMD & .TD0 files that you are trying to access? If you send me the names, or files,
I can extract the files for you and return a .ZIP that you can access from the PC.

The .LBR files you can access with NULU152 or any other CP/M library utility. I can extract or add files from a .LBR also.

Larry
 

giobbi

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Giovi,
What are the filenames for the .IMD & .TD0 files that you are trying to access? If you send me the names, or files,
I can extract the files for you and return a .ZIP that you can access from the PC.

The .LBR files you can access with NULU152 or any other CP/M library utility. I can extract or add files from a .LBR also.

Larry

Larry, thank you for your offer; I'm not interested (not yet!) to a specific file or file image; I just want to learn how to do that...

Giovi
 

giobbi

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The .LBR files you can access with NULU152 or any other CP/M library utility. I can extract or add files from a .LBR also.

This part left me a little confused. Nulu is a CP/M program; the .LBR file I have should be a disk image (I got it from the FOG list).
I was trying to extract the content someway to my PC and transfer it to Osborne vie MDM740.
If Nulu runs on Obsorne side, how can I use it if the image is on my HDD?
 

ldkraemer

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Giovi,
The squeezed type files that CP/M has are .ARC & .LBR. They are not IMAGE files and are not of DOS type. You can access them with
UNARC for .ARC and NULU for .LBR. The FOG files that I have also downloaded are of type .ARC, but inside them is a .LBR file.
So, I had to unarc the .LBR file and then access it to get MDM740.DOC.

You should also be able to use xmodem to transfer any .ARC or .LBR file from the PC to the Osborne 1.

Tomorrow morning during my free upload time, I'll send you some more utilities. I thought I had sent them previously, but maybe I
didn't get around to it. They should be about everything you should need.

I sent you a .ZIP file of all the files on the O1CPMs.IMD for the Osborne 1. It has SETUP.COM for setting the default Baud Rate
for your COM Port. Use Xmodem to transfer it to your Osborne 1 Floppy.

Your biggest problem is going to be the limited storage of the Floppy Drive. It would be better if you had Double Density Floppy's
with twice the storage.

Larry
 
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giobbi

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Giovi,
The squeezed type files that CP/M has are .ARC & .LBR. They are not IMAGE files and are not of DOS type. You can access them with
UNARC for .ARC and NULU for .LBR. The FOG files that I have also downloaded are of type .ARC, but inside them is a .LBR file.
So, I had to unarc the .LBR file and then access it to get MDM740.DOC.

You should also be able to use xmodem to transfer any .ARC or .LBE file from the PC to the Osborne 1.

Ok it makes sense; I also extracted the .LBR file from inside the FOG .ARC files on my PC, but I believed that .LBR was an image disk.
Is there any DOS tool capable to manage these formats?

And what about .IMD and .ID0 ?


Tomorrow morning during my free upload time, I'll send you some more utilities. I thought I had sent them previously, but maybe I
didn't get around to it. They should be about everything you should need.

If you mean the CPM-UTILS.ZIP with unarc, unload, nulu, etc., yes you sent me, no need to send again.

I sent you a .ZIP file of all the files on the O1CPMs.IMD for the Osborne 1. It has SETUP.COM for setting the default Baud Rate
for your COM Port. Use Xmodem to transfer it to your Osborne 1 Floppy.

Yep, I got it. I will look at it! :)

Your biggest problem is going to be the limited storage of the Floppy Drive. It would be better if you had Double Density Floppy's
with twice the storage.
Larry

I'm trying to fix the other Osborne One I have. It has DD units, but it started with a problem on drive B: and now both units are "dead". I received today the Floppy controller IC (MB8877) from USA, thinking (and hoping) it was the culprit, but it isn't. So now I have to dig into schematics and see what's going on...
Until then, only SSSD, unfortunately.

--Giovi
 

ldkraemer

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Giovi,
The ONLY way I know to access the .IMD & .TD0 files is with cpmtools (.IMD) and cpmtools w/libdsk (.TD0).

If you convert the .TD0 files to .IMD with the program TD02IMD (TD02IMD FILENAME.TD0) you will get FILENAME.IMD
Now you just need cpmtools (binary for windows) and the Osborn definitions (I've already sent those) to access the files
in the .IMD image.

If you want to work with the .RAW file versus an .IMD file, either of these two commands will create a .RAW file.

USE SAMDISK:
samdisk test.imd test.raw

USE IMDU:
IMDU file.imd file.raw /E /B

Now, you can just use cpmtools to access the files in the .RAW image.

man cpmls
man cpmcp

GET A DIR:
cpmls -f osb1 -d O1CPMS.RAW

COPY FILE FROM IMAGE:
cpmcp -f osb1 O1CPMS.RAW 0:*.COM /home/larry/osb1

COPY FILE TO IMAGE:
cpmcp -f osb1 O1CPMS.RAW README.TXT 0:README.TXT
(where the first README.TXT is in the cpmtools directory, and the last README.TXT will be on the .RAW Image for User 0)

REMOVE A FILE FROM IMAGE:
cpmrm -f osb1 O1CPMS.RAW README.TXT


Larry
 
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giobbi

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Messages
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Giovi,
The ONLY way I know to access the .IMD & .TD0 files is with cpmtools (.IMD) and cpmtools w/libdsk (.TD0).

If you convert the .TD0 files to .IMD with the program TD02IMD (TD02IMD FILENAME.TD0) you will get FILENAME.IMD
Now you just need cpmtools (binary for windows) and the Osborn definitions (I've already sent those) to access the files
in the .IMD image.

If you want to work with the .RAW file versus an .IMD file, either of these two commands will create a .RAW file.

USE SAMDISK:
samdisk test.imd test.raw

USE IMDU:
IMDU file.imd file.raw /E /B

Now, you can just use cpmtools to access the files in the .RAW image.

man cpmls
man cpmcp

GET A DIR:
cpmls -f osb1 -d O1CPMS.RAW

COPY FILE FROM IMAGE:
cpmcp -f osb1 O1CPMS.RAW 0:*.COM /home/larry/osb1

COPY FILE TO IMAGE:
cpmcp -f osb1 O1CPMS.RAW README.TXT 0:README.TXT
(where the first README.TXT is in the cpmtools directory, and the last README.TXT will be on the .RAW Image for User 0)

REMOVE A FILE FROM IMAGE:
cpmrm -f osb1 O1CPMS.RAW README.TXT


Larry


Larry, thank you, it was *exactly* what I was looking for! I tried it, it works fine.

--Giovi
 
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