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The Official Nabu PC Floppy Disk Controller thread

GaryFDes

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Joined
Jul 18, 2020
Messages
12
Welcome to the forum @GaryFDes !

I have almost finished building my NABU FDC, and I’ll measure and create a 3D printable backplate, and some standoffs, when I do.

- Alex
Thanks. I just finished building mine. Some suggestions.
1) There is a file on Klyball’s web page about checking your power. Very important! I was lucky that I only had to jumper across from -12 to the pin that was not connected and then swap the wires.
2) You have to switch over to an 8K ROM. This means cutting the 4K trace and jumper using the 8K trace.
3) More of a suggestion. It was easier for me to use an AT28C64 I had lying around. Probably cheaper for people too.
4) I found the best ROM was the NabuPC-U53-8k-90022900-RevGv13CF-Ben.bin. The other ones I could no longer do the cable boot. I only tried four of them though. Maybe someone can say more about the other files.
 

snuci

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Joined
Nov 22, 2012
Messages
1,540
Location
Richmond Hill, Ontario, Canada
Has anyone found any good standoffs for the card?

After trying a couple at Digikey, these are the ones that fit properly. https://www.digikey.ca/en/products/detail/essentra-components/DLSP-1-30M-01/3811816

Has anyone made a good backplate for the card?

Klyball made some. I am sure he will post them shortly. They work well.

4) I found the best ROM was the NabuPC-U53-8k-90022900-RevGv13CF-Ben.bin. The other ones I could no longer do the cable boot. I only tried four of them though. Maybe someone can say more about the other files.

I've used NabuPC-U53-8K-90037150-Ver-29-Leo-1.bin for everything as I believe that is the latest and I've done all my testing with this ROM.

Of course, if @ajacocks does some 3d designing, the more the merrier :)

Hope this helps.
 

twolazy

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May 22, 2011
Messages
2,239
Location
Chicago, IL
There are more NABUs with keyboards available, at the original price:

Thanks for the heads up! Pulled the trigger and got one. Very happy I was patient and didnt order one without a keyboard!
 

Klyball

Experienced Member
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Feb 15, 2014
Messages
162
Location
Surrey, BC
After trying a couple at Digikey, these are the ones that fit properly. https://www.digikey.ca/en/products/detail/essentra-components/DLSP-1-30M-01/3811816



Klyball made some. I am sure he will post them shortly. They work well.



I've used NabuPC-U53-8K-90037150-Ver-29-Leo-1.bin for everything as I believe that is the latest and I've done all my testing with this ROM.

Of course, if @ajacocks does some 3d designing, the more the merrier :)

Hope this helps.
I am using rom14 4k it seems to have Harddisk, floppy and cable boot
 

GaryFDes

Member
Joined
Jul 18, 2020
Messages
12
Been playing around with the disk controller and now I am using the NabuPC-U53-8K-90037150-Ver-29-Leo-1.bin 8k ROM. Unfortunately, I can no longer use the Chat or CPM site from NABU RetroNET. Is anyone else having this problem?
I can use the standard downloads using the NABU Internet adapter but not Cloud COM.

Am I going to have to go back to 4k ROMs in order to use it?
 

Wormetti

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Nov 3, 2012
Messages
88
Location
Melbourne, Australia
Homebrew needs to be modified to work with other rom versions. The loader required needs to promoted more and made easier, so more developers use it. Until that happens there are 2 roms you can use that should run everything:

ONABU supports floppy, homebrew and the cycles (NABU channel) http://6.buric.co/nabu/opennabu/

labomb patched nabupc-u53-ver14-2732-patched.bin to work with everything. https://gtamp.com/nabu/nabupc-u53-ver14-2732-patched.bin
 
Last edited:

twolazy

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May 22, 2011
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Chicago, IL
ty worm! I just got mine a week or so ago , and lost with the seperation of projects. I want a real floppy drive, but mass torage as well, plus NABU channel... Waiting on the 2 projects to intersect. Upside didn't have the fan paint issue.
 

labomb

Experienced Member
Joined
Mar 27, 2017
Messages
92
Been playing around with the disk controller and now I am using the NabuPC-U53-8K-90037150-Ver-29-Leo-1.bin 8k ROM. Unfortunately, I can no longer use the Chat or CPM site from NABU RetroNET. Is anyone else having this problem?
I can use the standard downloads using the NABU Internet adapter but not Cloud COM.

Am I going to have to go back to 4k ROMs in order to use it?

Just to add, my patched ROM that @Wormetti mentions above won't require the 8k jumper mod (not that it's difficult), it's still just a 4k ROM.

That said, it's probably inevitable that someone will come up with something that will mandate an 8k ROM at some point. :)
 

brijohn

Experienced Member
Joined
Jul 19, 2021
Messages
169
Location
Michigan
Been playing around with the disk controller and now I am using the NabuPC-U53-8K-90037150-Ver-29-Leo-1.bin 8k ROM. Unfortunately, I can no longer use the Chat or CPM site from NABU RetroNET. Is anyone else having this problem?
I can use the standard downloads using the NABU Internet adapter but not Cloud COM.

Am I going to have to go back to 4k ROMs in order to use it?
As others have said homebrew currently does not work with offical roms other then the 4k reva rom. This is because all other roms load at address 240d, whereas the reva one uses 140d. This has been known about for some time, but very few homebrew developers have done anything about it. I released a small loader that could be used with assembly homebrew sometime back that had a small position independent relocation code to basically copy the homebrew to a known address and run it from there. This is basically what the official main menu code does and why it works on all rom versions. Recently I have been playing around with creating a modified nabu_crt0.asm file for use with z88dk that will allow C based homebrew to do the same thing. I have a test version of the snake game and the hello world example from nabulib that both seem to work on all rom versions. So hopefully i can get that released soon.
 

GaryFDes

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Joined
Jul 18, 2020
Messages
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I do not have a 4K chip but I have an AT28C64B pins 28 and 26 tied together and set pin 2 to ground (pin 14) and it works like a 4K chip.

I have tried the nabupc-u53-ver14-2732-patched.bin but it puts a weird character on the main screen to the left of the load floppy prompt and then does not let me load CPM anymore from the GOTEKs I am using.

I have not tried the opennabu because I have not seen anything about which one to use. There are several on the download site. I could go by date but what does the "a" at the end mean? Is there any site that is explains what they are?

How are people getting files to their CPM disks? All I have so far is what I have made and what is on the vintagecomputer.ca download location. I have the last two chips coming in for the serial card so I assume I can transfer files using that technique. Is anyone able to copy the files to an image and then to an HFE file?

Gary
 

labomb

Experienced Member
Joined
Mar 27, 2017
Messages
92
I do not have a 4K chip but I have an AT28C64B pins 28 and 26 tied together and set pin 2 to ground (pin 14) and it works like a 4K chip.

I have tried the nabupc-u53-ver14-2732-patched.bin but it puts a weird character on the main screen to the left of the load floppy prompt and then does not let me load CPM anymore from the GOTEKs I am using.

I have not tried the opennabu because I have not seen anything about which one to use. There are several on the download site. I could go by date but what does the "a" at the end mean? Is there any site that is explains what they are?

How are people getting files to their CPM disks? All I have so far is what I have made and what is on the vintagecomputer.ca download location. I have the last two chips coming in for the serial card so I assume I can transfer files using that technique. Is anyone able to copy the files to an image and then to an HFE file?

Gary

The patched iteration is exactly the same as the stock v14 rom with the exception of the load addressing. I know of a few folks who are using it with no issues, and of course it works fine on mame as well. I suspect there is something unique with your configuration.
 

greghol

New Member
Joined
Nov 28, 2017
Messages
8
I do not have a 4K chip but I have an AT28C64B pins 28 and 26 tied together and set pin 2 to ground (pin 14) and it works like a 4K chip.


Gary
Gary

Do you mean 28 and 27? 26 is NC and 27 is /WE which you want high, i.e. connect to 28.

Greg
 

GaryFDes

Member
Joined
Jul 18, 2020
Messages
12
Labomb,
I found the problem and without more testing I cannot say that the problem with booting from the ROM you gave is a problem with the ROM.
I have two gotec drives. It seems that the flashfloppy version starts up much faster then the other nonflashfloppy version does and as such if I make the flashfloppy version of the gotek I do not have a problem with the ROM version you sent out. I can even run cloud CPM.
With only a floppy drive attached, no cloud, I still see the artifact that I have never seen before to the left of the insert text. See the picture.
1679349946423.jpeg
Everything seems to work so far.
 

GaryFDes

Member
Joined
Jul 18, 2020
Messages
12
Greg,
No, I think you have the pins wrong when converting from a AT28C64.
Take a look at the pin out of the AT28C64:
1679350191060.jpeg
Now to convert this to a 2732:
1679350254471.jpeg
Pin 24 on the 2732 (VCC) is pin 26 on the AT28C64B. So when the 4K rom is selected on the motherboard you need to supply pin 28 on the AT28C64B with what the motherboard is supplying to what it thinks is pin 24 on a 2732. This is pin 26 on the AT28C64B. Since pin 26 is not connected to anything in the chip you are just running from the location of pin 24 of the 2732 to the real VCC of the AT28C64B.

Get it? It works fine and is what the converters do with a conversion board.

Of course, you cannot let the last address float but that is why I tie it low saying to use the lower memory 4K on the chip. But I think you already knew that. I am just including the description for completeness.

Takes two wires. On small and one long and you have a 4K ROM chip substitute.

Gary
 

GaryFDes

Member
Joined
Jul 18, 2020
Messages
12
So now that I am using effectively the nabupc-u53-ver14-2732-patched.bin I ask again how people are getting CPM files to their disk drives?

Since I can now use Cloud CPM while also having the drives I see now that Cloud CPM does not see a real A: or real B: drive. Looks like that needs more work.

I can save to a real A: from Nabu Basic. I can use the Nabu filer to whatever drive I choose. Seems like the editor is no longer in the Nabu interface anymore so I cannot check that. I get a bong and some text saying optional component (or something like that) if I try to load the Nabu editor. Maybe in the future the editor will be added back?

Anyway, still fun playing with real drives and now playing with Cloud CPM.

Thanks again labomb.

Gary
 

Wormetti

Experienced Member
Joined
Nov 3, 2012
Messages
88
Location
Melbourne, Australia
So now that I am using effectively the nabupc-u53-ver14-2732-patched.bin I ask again how people are getting CPM files to their disk drives?
I think most people would use cpmtools to write to a disk image and then write that image to a disk or convert it to a format that your gotek firmware can read. Some might also use 22disk if they have an old DOS machine with a floppy drive/gotek.
 

greghol

New Member
Joined
Nov 28, 2017
Messages
8
Greg,
No, I think you have the pins wrong when converting from a AT28C64.

Pin 24 on the 2732 (VCC) is pin 26 on the AT28C64B. So when the 4K rom is selected on the motherboard you need to supply pin 28 on the AT28C64B with what the motherboard is supplying to what it thinks is pin 24 on a 2732. This is pin 26 on the AT28C64B. Since pin 26 is not connected to anything in the chip you are just running from the location of pin 24 of the 2732 to the real VCC of the AT28C64B.

Get it? It works fine and is what the converters do with a conversion board.

Gary
My bad. Right, My logic fail to realize that the 4KB to 8KB jumps from 24 pins to 28 pins per the JEDEC standard which I know but somehow zoned out during the reply.

Greg
 
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