Booting issues with expanded Jr

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Booting issues with expanded Jr

Postby Vorticon » Sat Oct 21, 2017 7:32 pm

Hi.
So I turned on my Jr this evening and it would not boot from the CF card even though it is recognized, and when I try to use a boot floppy it hangs after loading JRCONFIG. I have a Jr with 640K RAM in a sidecar, the V32 processor and the Jr IDE. The memory posts correctly and is reported as 732K by JRCONFIG. I can boot up with a plain DOS 3.2 floppy, but not with a DOS 5 one, but even then drive C (the CF card) is not recognized by the system. PalmZip works fine with the external Zip drive from DOS 3.2.
I'm suspecting a bad RAM chip in the expansion side car even though the posting is correct, but before I take the system down, I thought I'd check on the forum in case I am missing something obvious or if there are other issues I need to look into. It was working perfectly fine last night...
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Re: Booting issues with expanded Jr

Postby alanh » Sat Oct 21, 2017 11:27 pm

Have you tried re-seating the chips? PLCC sockets have issues with wear and oxidation over time. Though I haven't seen any evidence of problems with JR-IDE so far yet.
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Re: Booting issues with expanded Jr

Postby Vorticon » Sun Oct 22, 2017 8:49 pm

Well, it turned out that my V20 CPU was the culprit... Of course it took me a half day to eventually figure that while managing along the way to break off one of the pins on the motherboard's sidecar connector, corrupting my system backup on the zip drive and having my CF card go bad (so basically I lost all the software I had on it as well as the backup. Nice...).
Is there a source for the motherboard sidecar male connector? While I do have a backup Jr, I still would like to fix it if I can.
Still need to sort out why my DOS 5 boot disk is not working (I know it was patched at some point to work with the Jr), and my Backpack CDROM driver is refusing to load (perhaps it needs DOS 5?) although the Backpack 3.5" driver works fine.
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Re: Booting issues with expanded Jr

Postby Vorticon » Fri Oct 27, 2017 4:12 am

My only remaining issue is a problem with booting in DOS 5. I created a DOS 5 boot disk using my 486PC and patched its boot sector using PATCHDOS without issues. I am able to boot my Jr with it, however when I add Jrconfig in the CONFIG.SYS, it hangs up after displaying the Jrconfig blurb and RAM size. I have STACKS=0,0 in the first line. I've had no past issues with Jrconfig at all with DOS 5, so this is puzzling... No issues when booting with DOS 3.3 though.
I tried using jrconfig.dsk and jrconfig.nrd with various settings to no avail.
If anyone here has any thoughts on this, I would be eternally grateful. I spent almost 3 hours last night trying to get it to work...

-Walid
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Re: Booting issues with expanded Jr

Postby Trixter » Fri Oct 27, 2017 5:19 pm

What happens when you remove jrconfig.sys from config.sys?

Also, it is possible PATCHDOS has a bug -- try following Mike's original instructions for manually patching the boot sector of your boot disk and see if that works.
You're all insane and trying to steal my magic bag!
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Re: Booting issues with expanded Jr

Postby Vorticon » Sat Oct 28, 2017 1:30 am

Trixter wrote:What happens when you remove jrconfig.sys from config.sys?

Also, it is possible PATCHDOS has a bug -- try following Mike's original instructions for manually patching the boot sector of your boot disk and see if that works.


Without Jrconfig.sys, the system boots up fine from the DOS 5 floppy, although I run into memory issues with some programs as expected. FDISK however locks up the computer.
I did try manual patching using Mike's instructions, with no change. This is really weird...
I am using the JrIDE revision B for my memory expansion, but I get similar results with revision A, so I don't think that's the problem.
The key is trying to understand why jrconfig is working with DOS 3.3 and not the patched DOS 5.
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Re: Booting issues with expanded Jr

Postby Vorticon » Sun Nov 05, 2017 7:42 am

So a quick update of my ongoing tribulations here:

Turns out that the V32 switch is causing the hangup with Jrconfig. It works fine with V4 and V16. This is problematic given that all Jr and Tandy software require that V32 switch... Could this be an issue with the JrIDE's memory? Is there a way to test this out? I wonder if that might be the underlying reason my Backpack CDROM driver is now hanging the system when it was loading perfectly in the past...

Also, all my CF cards, with the exception of a 32MB Canon one I pulled from an old camera, are not allowing me to patch them for DOS 5. When I try Mike's manual patching instructions starting with the L 0 2 0 1 command in debug, I get the error "unable to read C drive". Even my old SanDisk 512MB CF card which had my original system is doing this. Furthermore, with fdisk all of them are showing a singe non-DOS partition which cannot be deleted except by using Superstor on my 486 PC...This is weird. I do plan to try a real LBA IDE hard disk once I get my hands on one. Also I can't seem to low level format any of the CF cards using Superstor.

This is really turning out to be a real challenge :(

-Walid
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Re: Booting issues with expanded Jr

Postby alanh » Sun Nov 05, 2017 9:41 am

Do you have just the 1 Jr? Can you try it in another machine?

The /V32 just affects the memory reservation of DOS memory for the CGA video window/memory. I wonder if you have developed a single bit error on a RAM chip and all these problems are just artifacts?
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Re: Booting issues with expanded Jr

Postby Vorticon » Sun Nov 05, 2017 2:57 pm

I have had similar issues on 2 different systems, that is before I broke a pin off the motherboard expansion connector on one of them...
I tell you this week has been full of gremlins for me, with no less than 3 vintage systems failing on me in different ways... Not to mention that I woke up this morning to find the blue screen of death on my desktop PC, caused by a corrupted partition.
Aaarghh! OK, deep breath, think positive thoughts... :mrgreen:
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Re: Booting issues with expanded Jr

Postby Trixter » Sun Nov 05, 2017 4:37 pm

Vorticon wrote:Turns out that the V32 switch is causing the hangup with Jrconfig. It works fine with V4 and V16.


Try v64. This provides two full pages of 320x200x16 which I've seen at least one PCjr-compatible title use.

Also, all my CF cards, with the exception of a 32MB Canon one I pulled from an old camera, are not allowing me to patch them for DOS 5. When I try Mike's manual patching instructions starting with the L 0 2 0 1 command in debug, I get the error "unable to read C drive". Even my old SanDisk 512MB CF card which had my original system is doing this. Furthermore, with fdisk all of them are showing a singe non-DOS partition which cannot be deleted except by using Superstor on my 486 PC...This is weird. I do plan to try a real LBA IDE hard disk once I get my hands on one. Also I can't seem to low level format any of the CF cards using Superstor.


Wipe, format and test them all on a modern system so you can be sure the problem doesn't lie with the cards themselves.
You're all insane and trying to steal my magic bag!
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