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Make your own NBIC and NeXT Development board?

 
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jroark



Joined: 17 Feb 2012
Posts: 75
Location: San Francisco, CA

PostPosted: Sun Oct 20, 2013 1:08 pm    Post subject: Make your own NBIC and NeXT Development board? Reply with quote

I was looking at the NBIC schematic and it looks like you could build an NBIC out of readily available parts. I was able to source all of these from digikey.

ICs
1x 74ACT573
1x 74F175
2x PAL16L8
1x 74AC138
11x 74HC574
1x 74AS04

Resistors
6x 10K

Caps
12x 0.1
1x 100

Does anyone have any clearer scans of the NBIC schematic? I'd like to digitize it in fritzing or eagle or something.

http://www.ti.com/lit/ds/scas538d/scas538d.pdf

http://www.ti.com/lit/ds/snos163a/snos163a.pdf

http://www.ti.com/lit/ds/symlink/pal16l8am.pdf

http://www.fairchildsemi.com/ds/74/74AC138.pdf

http://www.nxp.com/documents/data_sheet/74HC_HCT574.pdf

http://www.unicornelectronics.com/ftp/Data%20Sheets/74as04-als04.pdf

You could probably just program the logic into an fpga from the data sheets.


Last edited by jroark on Mon Oct 21, 2013 12:30 pm; edited 2 times in total
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cuby



Joined: 12 Jan 2006
Posts: 149
Location: Dortmund, Germany

PostPosted: Mon Oct 21, 2013 1:30 am    Post subject: Reply with quote

It should be possible to get away with two PALs and a bit of TTL logic - I remember building a Mac NuBus card years ago which required about the same amount of hardware. However, this minimal interface hardware might not support all NuBus features (like busmastering).

Perhaps it's a good idea to find a copy of "Designing cards and drivers for the Macintosh family" (I don't know if I still have my copy). There seems to be a PDF copy of the book online at http://dec8.info/Apple/Designing_Cards_and_Drivers_for_the_Macintosh_Family_2ed_May90.pdf (which is probably not 100% legal, but I doubt anyone at Apple will care nowadays) - I think NeXT's NuBus implementation is still reasonably close to what Apple and TI used in Macs and S1500 Unix/Explorer Lisp machine systems.

-- Michael
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jroark



Joined: 17 Feb 2012
Posts: 75
Location: San Francisco, CA

PostPosted: Mon Oct 21, 2013 12:30 pm    Post subject: Reply with quote

I found a copy on Amazon for $4.00
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cubist



Joined: 20 Sep 2007
Posts: 244
Location: Cambridge, MA

PostPosted: Mon Oct 21, 2013 4:20 pm    Post subject: Reply with quote

cuby wrote:
I think NeXT's NuBus implementation is still reasonably close to what Apple and TI used in Macs and S1500 Unix/Explorer Lisp machine systems.


Except for speed, I believe. NeXTBus is 25MHz, NuBus was 10?
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pentium



Joined: 23 Jun 2006
Posts: 1137
Location: Kamloops, BC

PostPosted: Mon Oct 21, 2013 4:44 pm    Post subject: Reply with quote

Yes. NeXTBus ran faster.
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-NeXT 68040 Cube with NS 3.3 and 64Mb ram
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jroark



Joined: 17 Feb 2012
Posts: 75
Location: San Francisco, CA

PostPosted: Mon Oct 21, 2013 6:47 pm    Post subject: Reply with quote

cubist wrote:
cuby wrote:
I think NeXT's NuBus implementation is still reasonably close to what Apple and TI used in Macs and S1500 Unix/Explorer Lisp machine systems.


Except for speed, I believe. NeXTBus is 25MHz, NuBus was 10?


That's funny. On the schematic in the archive, there is a part (not an input and not a xtal part symbol?) labeled "LOCAL BUS CLOCK" "X1 XTAL_OSC 10 MHZ". It appears to be connected to CPUCLK and LCKL pins as well as the CLK pin on the 74F175 (Johnson counter).

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cuby



Joined: 12 Jan 2006
Posts: 149
Location: Dortmund, Germany

PostPosted: Tue Oct 22, 2013 9:07 am    Post subject: Reply with quote

jroark wrote:
cubist wrote:
cuby wrote:
I think NeXT's NuBus implementation is still reasonably close to what Apple and TI used in Macs and S1500 Unix/Explorer Lisp machine systems.

Except for speed, I believe. NeXTBus is 25MHz, NuBus was 10?

That's funny. On the schematic in the archive, there is a part (not an input and not a xtal part symbol?) labeled "LOCAL BUS CLOCK" "X1 XTAL_OSC 10 MHZ". It appears to be connected to CPUCLK and LCKL pins as well as the CLK pin on the 74F175 (Johnson counter).

This is the clock for the local logic (on the NeXTBus card side vs. the Bus side) - however, I don't know why there is a separate CPUCLK signal on the local side...

Btw., is there any information on the logic equations required for the PALs? I couldn't find them in NeXTfiles section.
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