Mike's PCjr Page

I just installed a 3.5" as a second drive with Rapport expansion unit..

I set the config.sys
Device-driver.sys /d:2/c/h:2/s:9/t:80 ( which should indicate 720K )

but when formatting it still only formats to a 360K disk

wondering if the device-driver.sys..... should be BEFORE the JRCONFIG line in the config.sys file ?

anyone have any ideas ??

Jrconfig just sets the BIOS up for the 2nd drive. All the BIOS knows is how many drives are connected; it does not know about their type or size. (That does not come until the AT.)

Your goof is probably on the format command. If your version of DOS supports it, use the switches on the format command to indicate 80 tracks. (DOS 2.1 might not support those switches as those drives did not exist when it was released. You might need DOS 3.3.)

For DOS diskettes DOS gets the size of the diskette from the first sector of the diskette; there is a media type descriptor there. Format will set that correctly.

thanks Mike..
I am using DOS 5.0

The Format command has a couple different ways to ensure it is 720k depending on the Version..

Format b: /t:9/n:80
Format b: /f:720

This should be the correct format..
but when tried the response usually fails to format...hmmmmm

let me rebump this
seems like the 1.44 drives are picky..
anyone know how to strap them to 720k drive

Chuckphd53 wrote:thanks Mike..
I am using DOS 5.0

The Format command has a couple different ways to ensure it is 720k depending on the Version..

Format b: /t:9/n:80
Format b: /f:720

That's not right, it should be FORMAT B: /T:80 /N:9 -- you had the numbers reversed. Also, if you're using DOS 5, don't use whatever it was that you were using, use DRIVPARM. I added a 720k drive to a 1984 Olivetti system and my DRIVPARM=/d:1 /f:2 /t:80 works like a charm.

Thanks Jim...
Yes I do have it right, but typed it in backwards in the msg below, (it happens after 10pm)

I'm using DOS4.01 and have had some luck with the Panasonic JU-256A227, seems these work with the
device=DRIVER.SYS /t:80 /n:8 /h:2 declaration in the config.sys file...

I've tried two of the so far and they are good....

I am not sure if DRIVPARM works with DOS4.01 as you mentioned it comes with >DOS4
but here is a question.....

Should I be better served with DOS5 and I know it has to be patched, which I have not done or even investigated...
I did this back in the early days but don't remember without refreshing....

I do have DOS5, so I'm open to moving over to it...

chuck

Again, hope that's /t:9 instead of /t:8 :-)

DOS 4 is buggy, DOS 5 is not. I run DOS 5 on my PCjrs that have hard drives, and 2.11 (2.10?) for those without.

ok done....
as far as patching.... is there anything I should watch for..
as I mentioned.... 25 yrs has gone by.....
I think I have the patches..will need to look, but if you have a site /dir to go to even better..

I'm wondering if you might not have a 360k 3.5" floppy drive mechanism. The Atari 520ST used those when they were first released.