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Just completed the 80 Track disk controller MOD


Sinphaltimus

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Yeah, I've had to do this in the past a few times. Sometimes even running a wire from pin to pin for some mods (Amiga 500 kickstart 3.x). I like the dip switch blocks as a final solution.

I'm just stuck here, very anxious for a few more parts to get here before I can wrap up my immediate future TI needs.

Only a few things remain on my wish list. rs232 card + mod, that FPGA memory expansion and the F18A.

Then it's time to really dig in to programming the ti.

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Nice work! Looking forward very much to the return of my controller card too so I can start looking into some TI programming as well. I was too timid to attempt the upgrade myself and deferred to a couple of 'seasoned experts' on this forum. My config is also 80/80/40 and I have an HxC and 3.5 floppy in my PEB. I have a straight through cable which I made myself (so hopefully it's good) which is fine since I am okay with the floppy being DSK2.

 

Really want to attempt something that will use the F18a and the AMS memory board but I will need to re-learn 9900 assembler as it was the early 90s when I last wrote and ran something. Should be fun.

 

Love your disk jumper solution as well.

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As long as the power supply meets what the drive needs you should be good to go.

 

It looks pretty sharp too!

 

 

I was planning to run it off the peb.

I was planning on running all 3 off the peb with two power splitters.

Do you think it would have a problem driving 3 floppy drives?

At the most 2 operating at the same time for file copies/moves.

I don't ever see running all 3 at once.

 

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I was planning to run it off the peb.

I was planning on running all 3 off the peb with two power splitters.

Do you think it would have a problem driving 3 floppy drives?

At the most 2 operating at the same time for file copies/moves.

I don't ever see running all 3 at once.

 

 

I would not want to risk running 3 at the same time.

 

You could always get something like this:

 

HERE

 

I've used one of these before. You could eve work on putting in powerswitch inline to control the power at a flip of a switch on the case. I've done that before too. Just have to get the right switch that will take the amps being put out.

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I was planning to run it off the peb.

I was planning on running all 3 off the peb with two power splitters.

Do you think it would have a problem driving 3 floppy drives?

At the most 2 operating at the same time for file copies/moves.

I don't ever see running all 3 at once.

 

 

Some drives spin up even when they're not being accessed. So if you're copying files between 2 drives, you might have all 3 of them spinning and consuming power ...

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Prepping my cable for dsk1 and dsk2 (Gotek and 3.5" drives).

14233045_10206880794210362_7605351428951

 

 

 

And Done...



14184461_10206881038896479_1026262672623

 

 

So what I did was cut all the cables that were twisted, stripped and soldered each connection as per the specs (crossing pin 10 and 12).

Wrapped each solder point in electrical tape. (I don't have any shrink wrap) Then I folded the cables I didn't cut to take pressure off the solder point.
Taped everything down and wrapped it up.

Ready to go.

Edited by Sinphaltimus
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congratulations! i have a question s about you modification..can 80 track's modification eprom for the original ti disk controller ...hold up 3.5 DS/HD disk drives u1.44mb diskettes or only 720kb DS/DD disk drive units? my apologies for my bad english... :woozy:

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@ mmartin, It is designed to increase the capacity of the controller to use 80 tracks per side (instead of 40)--but still using single density. The physical drive mechanism and disk used could be of the 1.44MB type, but you would have to cover the hole that downshifts the disk to 720KB capacity, and even then, some folks (not all) have had issues using them this way. Most of us just use 720K disks in our drives (and the mix of physical drive types goes from 720K to 1.44M). The disk itself seems to be most important here: original 720K disks work great in either 720K or 1.44M drives, and while 1.44M disks work fine in the 1.44M drives, a lot of them have trouble in the 720K drives.

 

One final note: because this is working in single density, that means you are only getting 360K on that 720K-capable disk. That is still an improvement over the 180K you get with the same controller on a 40-track, 360K drive.

 

No apologies needed on the English either--my Spanish is much worse than your English. I only know 500-600 words. If you want German, Turkish, or French, however, things get much more interesting. . .in a good way. :)

Edited by Ksarul
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Here is a comparison of floppy drive cable pinouts for the TI controller vs. the PC controller in the Attaching external drive thread. As you can see, the TI controller has only one “Motor On” line that signals all drives connected to spin up their drives simultaneously. Unless a particular drive model requires both the “Drive Select” and “Motor On” lines to be active at the same time to power up the drive spindle, all drives will surely spin up when the selected drive spins up.


...lee

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Ok, so the important question here is, can the peb power 3 cards and three drives without worry of over loading the power supply?

 

I came across a mod for the power supply to up the amps from 1 to 2 and change the fuse. Do I need to think about doing that?

 

Worst case I can put a pc power supply inside the peb just to power the drives if I have to.

 

I'm just trying to gauge the risk. I'd there one just running it as is with 3 drives (1 half height, 1 3.5 and one gotek).

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I have thought about doing this mod, but I also thought Frankensteining a Mid tower case and move the TI Backplane board in the case. With a big enough power supply I would be able to run all my cards and drives I use without have to have external drive enclosures!

 

I really do not want to pull apart one of my PEBs to do it though. I have been watching eBay for a BackPlane board as i believe that is all I would really need. Well and maybe the cage section that guides the boards.

Edited by Shift838
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Yeah, I'm going to mod my beat up peb from ebay. Probably starting Monday.

 

I thought about the pc case thing but like you said, it would probably rely on the card slots and I don't have the right tools to manually cut them out for remounting. It's times like these I'd like to find a damaged, untested peb on the cheap.

 

I will document and take lots of photos.

Edited by Sinphaltimus
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Sinphaltimus, on 03 Sept 2016 - 02:37 AM, said:

Ok, so the important question here is, can the peb power 3 cards and three drives without worry of over loading the power supply?

 

I came across a mod for the power supply to up the amps from 1 to 2 and change the fuse. Do I need to think about doing that?

 

Worst case I can put a pc power supply inside the peb just to power the drives if I have to.

 

I'm just trying to gauge the risk. I'd there one just running it as is with 3 drives (1 half height, 1 3.5 and one gotek).

 

The wisdom from back in the day was that the 1A supply could run one full height or two half height drives. I did indeed try to run two half height and my older full height at the same time, and experienced brownouts (which you do not want while you're trying to save data), so needed an external supply.

 

These days, as you found, my PEB just has a PC power supply in it. ;)

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I took for granted switched power supplies.

 

It never occurred to be that 3 floppy drives would be too much for such a big "visually" power supply.

 

I'm also still not convinced I would have an issue in my case. I don't think the low power draw of the GoTek (not driving any mechanics) and the lower power of a 3.5 drive would equal the draw of a half height.

 

I'd be using the gt, 3.5 and half height.

 

But, since I have a very nice conditioned PEB and a not so nice one, I'll keep the nice one original knowing it's limitations and mod the other.

 

I ready like the half height external in the black case I found but I think I'd like all 3 drives to be internal. And I'm planing to do the lcd mod on the gt.

 

I'd also like to mount the lcd to a nice place on the peb, probably away from the drives, all the way on the left by the power button.

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