Mike's PCjr Page

Hello all,
I feel I'm missing something when attempting to patch DOS 5.0 for use with the jrIDE.

I'm able to install DOS 3.2 onto a CF Card within VirtualBox (VB) and able get it to successfully run on the PCjr.
I'm able to install DOS 5.0 onto the same CF Card (verifying the card isn't the problem) within VB and get it to boot in VB and newer hardware.

When attempting to run PATCHDOS from ftp://ftp.oldskool.org/pub/misc/Softwar ... TCHDOS.ZIP on 5.0 in VirtualBox, I receive the error "Boot sector read was not successful".
Is there an environment I'm to use to run PATCHDOS?
If I'm to boot from a DOS 3.2 floppy, I'd have to create a smaller C: partition which defeats the purpose of large partition support in 5.0.

When booting with DOS 5.0 I get the likely expected: This drive is too old to support LBA access.
Is there an image of patched 5.0 available I could dd to my CF Card?

I'm still reading through forums so apologies if this has already been covered.

Regards,

It has been covered, search Mike's posts for the manual way to do this. I never could get patchdos to work. This is best done on a real PCjr. Create a DOS 5 boot diskette and patch that. There is a way to patch another file, I think it is format.com, so then it will apply the patch to all media that you format. I haven't done the second patch on mine since I have a jr-IDE and DOM.

When booting with DOS 5.0 I get the likely expected: This drive is too old to support LBA access.

This doesn't make sense.
The LBA access message is coming from the BIOS, which is in a pre-DOS environment.
In other words, the version of DOS in use is not what is causing this message to be displayed.

Hello all and Thanks for the replies.
> KenG
Ah. Okay. Admittedly I didn't try to install DOS 5.0 on the PCjr itself. Time to figure out how to get DOS 5.0 on floppies.
> Hargle
I thought so to, yet was getting this on the same CF that DOS 3.2 successfully booted on. So the only change here was DOS 5.0.

I searched and no luck in finding an image of patched 5.0 available I could dd to my CF Card.

Regards

Careful about partitioning and formatting a DoM or HD in another machine then moving it to the JR. The JR-IDE BIOS always enables LBA and divides the total sector count by 63 SPT to get heads/cylinders. Whatever tool you use externally may not use that algorithm or do translation at all. I would get the CHS from the drive attached to the JR first then pass that CHS into whatever off-line manipulation tool you are using.

-Alan

Hello all,
Apologies for responding in an old thread, but it seemed the best place for this.
Is there a download location available of the DOS 5.0 image for use with the jrIDE that I could then dd to a CF Card?

Regards,

jhuyett wrote:Hello all,
Apologies for responding in an old thread, but it seemed the best place for this.
Is there a download location available of the DOS 5.0 image for use with the jrIDE that I could then dd to a CF Card?

Regards,

May be a little late here (older thread)
Seems a few folks have asked about using DOS5 with the JrIDE, but the issue is getting DOS5 onto a 5.25 floppy...
I don't know of a program for the JR that allows extraction of an image to a floppy, this would be pretty handy and I would like a copy if it exists...

But I've made an Image of a boot DOS5JR disk
this is bootable with the Config.sys (stacks=0,0)
nothing else is on the image.....

if someone tries this let me know if it works, if so maybe Mike (if ok) can put this as a download somewhere .

http://www.linearlogix.com/PCJR/DOS5JR.img
Chuck

There are plenty of programs that can read and write disk images that also work on the PCjr. DskImage (available here) is one that I wrote that is more aggressive about retries for those wonderful, old marginal diskettes.

As for hosting DOS bootable images ... not here. It's a copyright problem.

Recently started having issues with my Hyperdisk DOM and the JRIDE, but it seems when I use PCTOOLS or NORTON.
I get some corrupted junk on the DOM..
I am gonna assume that these programs like to handle the headers FAT and other items a little different, not an expert on that...

so I'm trying out a 'real' spinning hard drive to night...
which brings up my question of DOS 5 FORMAT.COM
Using the patch to correct the disk to properly work is fine
but it was mentioned to parth the DOS5 FORMAT.COM file , so when used it will automatically include the 'patch'
is there a special / different way to patch the .COM file before I get into performing this task..

It's the same patch but the offsets are different. Format.com has a copy of the boot sector embedded within it, so when you patch Format.com that is what you are looking for.

I really thought that I had the patch process well documented; it seems to be a recurring theme. The previous threads should cover it.