Kaypro 4/84 questions

Brian Wheeler bdwheele at indiana.edu
Thu Nov 8 09:20:57 CST 2007


On Wed, 2007-11-07 at 14:22 -0500, Allison wrote:
> >
> >Subject: Re: Kaypro 4/84 questions
> >   From: Brian Wheeler <bdwheele at indiana.edu>
> >   Date: Wed, 07 Nov 2007 11:26:54 -0500
> >     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
> >
> >On Mon, 2007-11-05 at 17:54 -0400, Roy J. Tellason wrote:
> >> On Monday 05 November 2007 13:13, Brian Wheeler wrote:
> >> > * I'd like to replace the 2nd drive with a 3.5" floppy.  I've found a
> >> > Sony HD drive along with a power and plug converter.  Knowing that PCs
> >> > use a twisted cable scheme, what things should I be aware of when
> >> > cabling in this new drive?
> >> 
> >> The twist in the cable was to not have to worry about jumper settings which 
> >> you had to deal with prior to that point.  Those drive select jumpers are 
> >> marked,  depending on the brand,  either 0-3 or 1-4 on the drive electronics, 
> >> with the first two choices being the ones commonly used (0 and 1,  or 1 and 
> >> 2).  The cable with the twist setup has both drives set to the second choice,  
> >> so you probably won't need to worry about messing with anything there,  
> >> selecting the drive should be apparent as Kaypros tend to leave the light on 
> >> all the time.
> >> 
> >> > Will it be supported in some manner by the software?
> >> 
> >> Hm,  kinda doubtful,  though I couldn't say for sure as it's been a long time 
> >> since I dove into those particular interface specs.
> >> 
> >> > Its not a big deal if it turns out to be a 360K 3.5" floppy,  as long as its
> >> > readable by my linux box. 
> >> 
> >> That might just be what you end up with.  Do tell us when you find out,  I'd 
> >> be curious to know...
> >> 
> >
> >I've got the 3.5" drive installed and cabled and it seems to be working
> >rather well.  I ended up using vice grips to get the screws loose in the
> >drive cage since the heads kept wanting to strip.  As I suspected, it
> >really thinks its just a DSDD 5.25" drive.  I formatted a disk using
> >mfdisk as an IBM 9 sector DS disk and could read it (as 360K) without
> >problems on my linux box.  
> >
> >The drive I ended up using was a chinon FZ-357 which has a jumper for
> >RDY as well as drive select jumpers.  It also had the interface pins on
> >the same side as the original disk so I could use the original cable.
> >All of my other 3.5" drives had it on the other side, but the cable
> >wasn't long enough to shift sideways enough.
> >
> >Its weird when it does a format since it counts tracks from 0 to 79 but
> >its really counting cylinder 1 as tracks 0 and 1, etc.
> >
> >However, trying to read a kaypro formatted disk isn't working.  It reads
> >4K and then fails.  Anybody used setfdprm on linux to set up reading
> >kaypro iv/10 disks?   They look like they're 10 sector (numbered 0x0a -
> >0x13), rate=2 disks.  
> 
> You may have to notify the software of what format is being used.
> 
> 
> >I'll probably mount the 5.25" DSDD drive in my linux box as well, but
> >it'd be nice to know how to read disks without hassle :)
> >
> >Now for some more questions:
> >
> >* is it possible to run CP/M 3.x on it, or am I limited to 2.2G?
> 
> Yes, but without any banked memory.
> 

I may give that a try, then.


> >* what's the J9 header for?  It looks like it has 8 data bits and 8
> >address bits wired to it (at least according to the schematics I've
> >found).  Seems like it'd be possible to hang a home-made IDE interface
> >onto it (if I ever get time/inclination)
> 
> Its host interface  for WD1001HDO HDC, Sorta like IDE save for the 
> board was bigger than the drive, it wasn't integrated, it was 8bit
> and the registers were slightly differnt.   To do IDE with that 
> should be easy as its basiccally the process or bus for IO. There 
> will not be software support (BIOS) unless you do it. 
> 

I suspected as much...maybe a good Christmas break project :)


> 
> Allison
> 
> >
> >Thanks to all of the suggestions and advice!
> >
> >Brian
> >
> 




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