PCjr 1.44 floppy controller

From: Brian Heise <nampcjr_at_yahoo.com>
Date: Mon Mar 3 19:09:00 2003

Fred
Thanks for the info. Actually, I did do a modification to mine. I guess I should clarify my 3.5" floppy mod. I just hacked the Drive Select, so I could use the standard Racore floppy drive cable. I didnt want, or have the means, as I do now, to make my own cables.
Wish I had one of those controllers!
Brian
 "Fred Cisin (XenoSoft)" <cisin_at_xenosoft.com> wrote:On Mon, 3 Mar 2003, Brian Heise wrote:
> I am curious if anyone ever had one of the Legacy Enhanced Floppy
> Controllers for the PCjr, was ever able to duplicate one, or know if

"have?" no
"ever had" yes
I sold my Jr's a few years ago. But the guy who bought the one with the
"Legacy" board brought it back to sell it at VCF last year.


> it was ever possible to modify the current controller to take on a
> 1.44mb capacity.
> I have a Racore unit with a modified 3.5" 1.44mb drive that acts as
> 720kb, and is fantastic, but would love that extra storage space if
> available!

720K does not require any modification. See also, the PC-JX (never sold
in USA)
Using a 1.4M drive for 720K usually doesn't require any mods.

But getting 1.4M to work on a JR poses some problems.
The STOCK controller for the Jr. would need a minor hardware mod to get
the 500K bits per second data transfer rate.
And the stock controller does NOT do DMA. Can you write the code tight
enough to do the data transfer through the CPU at "high density" rates?

--
Fred Cisin cisin_at_xenosoft.com
XenoSoft http://www.xenosoft.com
Received on Mon Mar 03 2003 - 19:09:00 GMT

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