PCjr memory question

[oblivion]

Finally decided to mess around with my pcjr and have a question about memory. It currently has a modified side card and on POST it counts up to 640k. In DOS 3.2 it only seems to see 128k. I've found conflicting information on if you need to run a TSR for DOS to see the extra memory, can anyone clerify?

I tried running the newest version of pcjrconfig but when I run it it just gives an odd message about inserting a disk in drive B and hitting return. There is no drive B but if I hit return it reads drive A and gives the same message. ( I'm at work now so I'm recalling the message from memory). Maybe the version I downloaded is bad.

 

[Eudimorphodon]

Yes, you need a driver to sort out the PCjr’s goofy memory map for DOS to see more than 128k

 

[mbbrutman]

You should look for JRCONFIG.SYS - it's a device driver that configures the machine to handle the extra memory. There is no conflicting information - if you want to use the extra memory under DOS you need a device driver.

If you use a search engine you will find it, including the background on why you need it.

 

[oblivion]

Several sources I read and videos I watched where they obviously were running more than 128k of memory completely omitted any mention of having to run any TSR so I wasn't sure If maybe there were some versions of DOS where it wasn't needed or some other trick.

Anyway, I got it running now. there must have been some issue with the version of JRCONFIG I was using. I downloaded an older version and ran the install which seems to have patched my dos floppy disk so now on boot it runs...whatever it runs so now I'm getting the full 640k, thanks!