Loading files to floppy

General discussions related to the Altair 8800 Clone

Loading files to floppy

Postby barney » December 10th, 2013, 1:55 am

The PCGET program uploads one file at a time. Is there a way to upload multiple files, or to create a .dsk file on the PC itself?
barney
 
Posts: 12
Joined: October 31st, 2013, 11:19 pm

Re: Loading files to floppy

Postby AltairClone » December 10th, 2013, 1:03 pm

Kermit and Modem7 had multi-file transfer modes. However, source code may be required to modify the programs for the serial hardware of the Altair instead of a modem. Also, finding the compatible PC side of the program -- particularly Modem7 -- may not be easy.

Wouldn't be too hard to spin your own multi-file transfer utilities if anyone is bored!

Authoring and modifying .dsk files is easily done with the Altair Simh emulator.

Mike
AltairClone
Site Admin
 
Posts: 421
Joined: April 5th, 2013, 10:55 am

Re: Loading files to floppy

Postby barney » December 15th, 2013, 3:11 am

I downloaded the Altair Simh simulator(altairz80) which has a default of 254 tracks and a .dsk filesize of 1088 KB. I tried to reset the format of B: to 77 tracks using the D TRACKS[1] 77 command but have not been able to get the number of tracks to actually reset. Is there some trick?
barney
 
Posts: 12
Joined: October 31st, 2013, 11:19 pm

Re: Loading files to floppy

Postby AltairClone » December 15th, 2013, 12:51 pm

There AltairZ80 Simh emulator can run a wide variety of configurations, so it gets a bit confusing. To work with images compatible with a real Altair floppy and with the Altair Clone, here's what I'd recommend:

1) Download the emulator executable (altairz80.exe) at http://www.schorn.ch/cpm/zip/altairz80.zip.
2) Download the Burcon CP/M 2.2 software at http://www.schorn.ch/cpm/zip/burcon.zip
3) Optionally, you can also download additional Altair software at http://www.schorn.ch/cpm/zip/altsw.zip

Unzip each zip file into their own folders. Copy the altairz80.exe file from the altairz80 folder into the burcon folder you created and also into the altsw folder you created.

Start inside the burcon folder. Double click altairz80 to run the emulator. At the sim> prompt, type "do cpm" and press return. Burcon CP/M will boot. The CP/M program "R.COM" is used to read a file from the PC into the CP/M file system. The program "W.COM" is used to write a file from CP/M to the PC. The files read and written must be in the burcon folder (i.e., the same folder from which altairz80 was executed).

You can copy any of the disk images from the Altair Clone directories into the burcon folder and work with them as well. Either name the disk image "cpm.dsk" or you can edit the file "cpm" (you may want to change the name to "cpm.txt" so it is easier to bring up the text editor) and put in the disk image file name where you see "attach dsk0 cpm.dsk" line. Note you can also add additional disks (up to four total) with additional "attach" lines using "dsk1" "dsk2" etc. Note that the simh boot command becomes "do cpm.txt" if you add the ".txt" file extension to the command file.

In order to get "R.COM" and "W.COM programs onto a new disk, first save these programs to the PC from the original burcon CP/M disk using W.COM to write R.COM and W.COM to the PC. Then boot the new disk image onto which you want to load these programs. Once CP/M is running and you have the A> prompt, type ctrl-E to exit to the simh console. At the sim> prompt type "load r.com 100" and press return. This puts the R.COM program into 8080 memory at 0100h. Then type "g" and return to return to CP/M. Press return once or twice to be sure you have the A> prompt. Type "SAVE 16 R.COM" to save the read program from memory into a file. Now use R.COM to load W.COM and you're all set.

Note that the CP/M versions in the altsw folder are customized for the emulator and may not be ideal versions of CP/M for the Altair Clone or for a real Altair floppy.

Mike
AltairClone
Site Admin
 
Posts: 421
Joined: April 5th, 2013, 10:55 am

Re: Loading files to floppy

Postby barney » December 15th, 2013, 6:12 pm

I am still missing some concept. I got Simh & Burcon CPM 2.2 from the Shorn site and I saved W.COM and R.COM from the Burcon CPM to the PC. Then I tried two different methods:

1. Loaded Burcon CPM2. (sim> do cpm2) CPM booted and signed on.
2. Broke to Simh with CTRL-E
3. Attached an Altair Clone floppy to drive B: (sim> attach dsk1 cpm48k.dsk)
4. Returned to CPM (g)
5. Did a DIR B: and got the garbage below:

http://www.resysinfo.com/uatx-install/cpm2.JPG

Then I tried:

1. Tried to boot in Altair Clone CPM:
Code: Select all
sim> attach dsk0 cpm48.dsk
sim> boot dsk

2. The simulator never booted up CPM, but I was able to break out with CTRL-E

http://www.resysinfo.com/uatx-install/cpm48k.JPG
barney
 
Posts: 12
Joined: October 31st, 2013, 11:19 pm

Re: Loading files to floppy

Postby AltairClone » December 15th, 2013, 6:42 pm

Barney, it looks like you're still running the CP/M 2.2 you originally downloaded instead of the CP/M in the Burcon folder. I can tell because the command file in the Burcon folder is "CPM" not "CPM2" and the screen shot you posted shows you are still running the SIMH version of CP/M and not the Burcon version.

Try this: Delete everything you've install related to SIMH and download just the the links I've listed in items #1 and #2 in my previous post. That should eliminate some of the problems you're having.

Keep in mind that two different builds of CP/M (doesn't even have to be different versions) could have completely incompatible file systems depending on the drive parameter tables present in the BIOS. That is why the large-disk CP/M 2.2 you booted could not properly read the Altair compatible cpm48.dsk you attempted to mount on the 2nd drive.

You'll notice there are two command files in the Burcon directory (cpm and sysgen). Add ".txt" to both of these and then double-click them to see the content. In the "cpm.txt" command file you'll see:

set cpu 8080
attach dsk0 cpm.dsk
load dbl.bin ff00
go ff00

"set cpu" is obvious.
"attach dsk0 cpm.dsk" sets disk zero (the boot disk) to be the disk image file "cpm.dsk"
"load dbl.bin ff00" puts the standard Altair Disk Boot Loader ROM into memory.
"go ff00" executes the Disk Boot Loader

Your attempt to boot "Altair Clone CPM" failed because the commands to load the Altair disk boot loader and execute the loader were not present. Again, SIMH has all sorts of options and commands and can be very confusing. That is why I'd recommend following the steps I posted previously as closely as possible when getting started.

Let me know how it goes!

Mike
AltairClone
Site Admin
 
Posts: 421
Joined: April 5th, 2013, 10:55 am

Re: Loading files to floppy

Postby barney » December 15th, 2013, 7:59 pm

Works like a champ. Thanks.

Yes very confusing between the Simh documentation and the altairz80.com documentation. I thought the CPM2.2 I had loaded was the Burcon version.
barney
 
Posts: 12
Joined: October 31st, 2013, 11:19 pm


Return to General Discussions

Who is online

Users browsing this forum: No registered users and 1 guest

cron