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DOS 3.3 or DOS 5.0?

PostPosted: Wed Mar 16, 2016 6:16 pm
by Tempest
Thanks to Alan my jrIDE is back up and running and I have a shiny new 2GB DOM (turns out my old one was fried). Now I need to decide what DOS to put on it. I had been using DOS 5.0 but I'm wondering if 3.3 wouldn't be more compatible with games. I didn't run into anything that wouldn't run under 5.0, but I'm sure there's stuff out there. There's also that annoying delay when doing the DIR for the first time (although I can live with it). What do most people here do with their PCjr setups?

Also, if I decide to go with 5.0, does anyone have the 5.0 disk files? I've since lost my disks since I installed it last. I also seem to recall that I had to manually decompress all the DOS files the last time I did it and that was extremely annoying. Does anyone have the 5.0 files already uncompressed? I have a 3.5" floppy drive so I can get 720K per disk so size shouldn't matter unless there's actually an install program that you need to use now. Thankfully I still have my 5.0 boot disk so I was able to fdisk the drive and setup/format the partition.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 7:23 am
by Hargle
My vote is 5.0.
I say this primarily for the purpose of being able hook up the PCjr DOM to a modern machine to push/pull files to it.
Unless I'm remembering incorrectly, dos 3.3 and below use a different FAT format and whenever you read a disk formatted from a newer/modern DOS with it, you'll get a disk read error.

I have PCjr patched DOS 5.0 disks that I can make copies of for you if you'd like. Since I only have a 5.25" drive on my machine, I ended up with 3 disks, and that included some other useful utilities like list and pkzip/unzip in there too.

The painful first DIR listing is something I've wanted to investigate someday. I bet command.com could be patched to skip performing the free disk space check completely or pre-load a value of "lots" into the variable it is likely checking to know if this was the first DIR or not.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 12:54 pm
by Tempest
Do you just copy the files into the dos directory like with 3.3 or do you have to actually use the install program?

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 2:49 pm
by jmetal88
Tempest wrote:Do you just copy the files into the dos directory like with 3.3 or do you have to actually use the install program?


I would use the install program on another PC to unpack the files (maybe use a virtual machine or something), then manually make your PCjr's hard drive bootable and copy the installed DOS directory over.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 2:55 pm
by Tempest
So you do have to use the install program then? You can't just copy the files like with DOS 3.3?

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 7:35 pm
by jmetal88
Tempest wrote:So you do have to use the install program then? You can't just copy the files like with DOS 3.3?


You can't from the install disks. You can if the files are already installed somewhere.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Thu Mar 17, 2016 8:20 pm
by Tempest
Ok, I think I got it. So if someone installed dos 5 on a system and copied the files onto a disk from that installation, then I could copy the files from that disk into the dos directory on my Jr.? It's just that you can't copy directly from the original dos disks right?

Assuming I got that right, does anyone have those files handy?

Re: DOS 3.3 or DOS 5.0?

PostPosted: Fri Mar 18, 2016 6:49 am
by Hargle
Yeah, the files on DOS 5.0 and higher are compressed with a proprietary compression, so copying them off the original disks isn't useful. However, the uncompressor (expand.exe IIRC) is right there on the disk as well, so you can manually extract any of the files you need without using the installer. Once expanded, you can copy the files anywhere you need, including to another computer.

The 3 disk offer I've made to you includes a bootable 5.0 disk, and then expanded versions of all the other DOS files you'll need, plus a few simple utilities.

1) Boot to the diskette
2) run FDISK
3) set up your partition(s)
4) reboot to the diskette again
5) run FORMAT C:/S
6) reboot to the hard drive
7) run MD DOS
8) copy files off diskettes into C:\DOS

* for a DOS 5.0 machine on a PCjr, some additional patching may be required. There is a thread here as well as a utility to help with that.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Fri Mar 18, 2016 9:23 am
by Tempest
That sounds perfect, I would like to take you up on your offer. I'm already at step 7, I just need the disks with the files to copy.

Now I remember what I had to do last time, I had to run that expand command for every file and it took forever. Never doing that by hand again. :)

If you ever figure out how to fix that DIR delay (the free space calculation) please let us know. I think everyone here would be grateful.

BTW is there any reason at all to go with DOS 6.22 over 5.0 on the PCjr? I can't believe there would be, but I thought I'd ask.

Re: DOS 3.3 or DOS 5.0?

PostPosted: Fri Mar 18, 2016 8:28 pm
by Trixter
Hargle wrote:The painful first DIR listing is something I've wanted to investigate someday. I bet command.com could be patched to skip performing the free disk space check completely or pre-load a value of "lots" into the variable it is likely checking to know if this was the first DIR or not.


I would be very wary of that. It has to calculate free space sometime or else you could corrupt DOS operation or the filesystem.

A user over on VCF created a utility that helped, but I'm still wary of it.