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Bill good eye , from the pin out above it show drive pin 10 and 12 joined so my image is wrong not pin 8 and 12.I can't see this a a good idea for newer drive maybe ok for jumper selectable older drives I would leave it out

I will correct the drawing
check the 610 schematic it has the jumper settings for 2 sided drives
Between all the old drives and new drives there is no clear conception scheme ,that's why I left lots of pads for experimenting

I can confirm the 2 sided drive mod for the 610 with the d-13
also the white jumper on the d-13 could be placed on the 50 pin header pin 26/28 instead of soldering it to the 34 pin header , I believe this would only be for using 2 double sided drives otherwise can be left off.

tested and working

MPI-51 with D-13 no modifications
Toshiba nd-354A 720KB 3.5 with D-13 1 side only no modifications
Toshiba nd-354A 720KB 3.5 with D-13 2 side 80 track/per side 610 mod/d-13 mod
next up using a 1.44 drive as a 8 inch replacement

I made the mods to the 610, and added the jumpers on the D13 and both sides of my drive are now supported! I added pins, so I could change the jumpers in the future, if necessary.
/Jeff

So, on a whim, I decided to hook up another floppy drive I had lying around... An Epson SD-800.
This FDD combines a 3.5", 1.44 Megabyte floppy disk drive with a 5.25", 1.2 Megabyte floppy disk drive in a half-height chassis.

I set the SS1 jumper to 'B', to select the 5.25 drive as A, instead of the 3.5 drive.
I set the SS2- Motor Speed jumper to 'D' to select 300 RPM (instead of 360).
The drive worked wonderfully! I was able to HOme, INit, SAve, and CAll data to and from both sides (SElect A and SElect B). I was not able to boot with my other disks, though. I am trying to figure that out now.

I wonder if I can get the 1.44MB floppy to respond as Drive C and D.
/Jeff

OK, I figured out why it wouldn't boot from my other disks. This is an 80 track drive!!! I did a raw dump of the data on my boot disk (made with a single track drive) and Track 0 was fine; Track 1 was garbage, Track 2 matched the boot disk Track 1, and so on. Every other track was real data!

So In order to use this disk drive to its fullest, I need to modify the OS to use 80 tracks. This is cool!

Does anyone know if this drive can be put into a mode to read a 40 track disk.....for compatibility purposes, or is it hardwired to be an 80 track drive?

/Jeff

Hi Jeff, I want one of those cool drives,

The mpi drives cover 40 tracks over the whole drive and the new drive covers 80 but is only going half way right now till you change the os, there might be away to get it to double step but those old drives are flakey at best, so your better off doing new disks with the new drives. that 1.2 could be used as a 8 inch replacement if you bump up the speed on the 610, and reset the timing.

you might need to do surgery to get the 1.44 drive working/ i'm in the middle of working on getting 1.44 going and had to do some work on the drive to get it working

So, basically, the change to go to 8" drive emulation is just modifying the drive (and the 610) to store 12 sectors per track instead of 8, right?

DOS changes to PGS/SECT ; max TK 76 and 77 in places; DIR Tk 8/12. Grab my 8" images.
Bigger is better.

I changed my boot file here

26CA = 77
2769 = 76
2779 = 76
27ED = 0E

then you could load up 8" images you could also increase to 80 79 79 in you wanted the extra couple tracks
I have had success with the 1.44 drive writing 13 sectors working solid

Anyone looked at the internals of the numerous USB External 3.5 drives available. Do they use a sub board that connects to standard 34 pin I/F ??

PS might be possible ...

http://www.techpowerup.com/forums/threa ... ve.151939/
http://www.martinruss.com/sy99adapter.html