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Error with expanded memory

PostPosted: Wed Nov 01, 2017 3:44 pm
by pzsjgkz
I am trying to get the Jr to boot DOS with expanded memory. The jr has a 640K side card. I ran the install program from the DOS2.1 PCjr memory options disk and re booted and I get a error to check the DIP switches. Fine but I have nada docs on the side card. Is there a common dip setting for those ?

It completes the initial POST for RAM fine, it counts 640K and I ran the loop test from the Jr memory options disk and it saw no issues so I guess the sidecard is ok ? Any help would be appreciated.

Joe WA4UJY

Re: Error with expanded memory

PostPosted: Wed Nov 01, 2017 4:01 pm
by pzsjgkz
SO i played with the switches and i get that each DIP is 128K and when I set it to 256K I get no errors on DOS boot with the disk I used to run the expanded memory install. Above 256K it fails.

Re: Error with expanded memory

PostPosted: Wed Nov 01, 2017 7:51 pm
by Trixter
You should configure it such that it counts to 640K on the boot screen without any errors. That is the correct hardware configuration. If you are getting errors booting a disk with your full 640K functional, then the problem is with the boot disk, not the hardware. What is on your boot disk? What is the "expanded memory install" you're trying to install?

Re: Error with expanded memory

PostPosted: Wed Nov 01, 2017 9:00 pm
by Brutman
It would help us if you told us the exact contents of your config.sys file and what memory manager you were using to add the extra RAM.

Re: Error with expanded memory

PostPosted: Thu Nov 02, 2017 6:03 am
by pzsjgkz
Thanks for the help. I used the install program from the PCjr memory options disk that came with DOS 2.1
The config.sys file contains one line
DEVICE=PCJRMEM.COM
And pcjrmem.com is on the boot disk.

Looks like the install.com copies the config.sys file and pcjrmem.com to the boot disk.

Re: Error with expanded memory

PostPosted: Thu Nov 02, 2017 9:40 am
by Trixter
Okay, so while that is not as good as jrconfig (look on http://www.brutman.com/PCjr/pcjr_downloads.html to get jrconfig), it should work. So, on a boot disk with device=pcjrmem.com in the config.sys, on a system that counts all the way up to 640K, what exactly are you seeing when you try to boot?