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Project30 - IIsi NuBus adapter in SE/30 trials - take 3

Trash80toHP_Mini

NIGHT STALKER
:eek: SWEET!!!!!!!!!!!!!!!!!!!

Have to check my datasheet dump, but looks like it's based on TI's off the shelf NuBus Controller/Bus Transceiver (2 req'd) Chipset. So conversion of the 16MHz PDS to 10MHz NuBus takes place on that Card and the 62(?) pin header extends NuBus to a board not too dissimilar to the Xpanse N400 Motherboard in my PCI to NuBus Slot(4) expansion box. That's what I was figuring even before seeing that as 10MHz signalling over a cable is far less problematic than 16MHz.

YAY! They didn't have a shot of the solder side did they?

< crosses fingers >

 
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Bolle

Well-known member
Not a lot going on on this thing... a few PALs and a ROM, probably only for holding the declROM.

There must have been some stuff going on in the external box as well or they did do the whole Nubus controller thing in those 5 PALs.

 

Trash80toHP_Mini

NIGHT STALKER
PALs fix SE/30 bus mastering borkage(?) along with interfacing with the TI NuBus Chipset. I'll post links to the Datasheet for that controller and a pic of the block diagram from it ASAP. It's all signal lines with the Address/Data buses connecting directly to the pair of Transceiver/MUX ICs.

 

nickpunt

Well-known member
No solder side pics unfortunately. I have been kicking myself for a long time for not bidding on this. I assumed someone here had picked it up but I haven't heard a peep from anyone. If the serial is to be believed we know there are at least 7045 of them in the wild, minus the thousands in trash heaps.

 

Trash80toHP_Mini

NIGHT STALKER
LOL! If their solid, 100% unobtainium build Twin SE PDS Slot Card/Box for the Portable ever winds up on eBay, I expect to see blood running out of my internet connection at snipe time.

 

Trash80toHP_Mini

NIGHT STALKER
Was that auction listing for the interface card only? Got box pics?

< crosses fingers once more >

Xpanse_N400_Motherboard-00.jpg

Sorry about the crappypic. I'll try to get a better one outside in the shade when it's sunny. Drab day here in the Triangle.

56C07 JK copy on the three TI ICs on the left probably won't be legible even in good light. On the right are 74ACT11802NT, again from TI and Dallas' and itsy bitsy little DS1010-100.

Slots have HEX rotary ID switches. They appear to be set for 7 (strange, it's unsupported in the Mac's NuBus implementation) A, B and C from left to right.

 

nickpunt

Well-known member
It was for the board only. I forgot to save the listing unfortunately, but maybe if someone has one of those ebay price scraper sites they could look for it - it was sold by 'electronicspart' (https://www.ebay.com/usr/electronicspart) in Nov 2013, and purchased by p****m, someone who I'd seen bid a lot at that time in vintage computing.

Info on the expanse box was listed here before at this URL: http://68kmla.org/forums/viewtopic.php?f=16&t=14915  but that's no longer accessible :(

 
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Trash80toHP_Mini

NIGHT STALKER
All these disappeared threads are driving me up the wall! If they're only delayed, that'd be great. If they're gone, we can rebuild the info in new threads. At least the piccies are back! [:)]

Can we dumpsterdive the wayback machine for the missing thread pages? Dunno how that works.

 

nickpunt

Well-known member
Unfortunately the dynamic nature of the page URLs (e.g. the ? after /viewtopic.php?f=16&t=14915) mean that wayback machine isn't archiving them. I'm also kind of frustrated by the thread situation, given that so much of this work is archival in nature and I spent a lot of time collecting notes that link out to old topics. I know mla is run by volunteers so I don't want to complain and super appreciate all the work they do. Meanwhile just hoping threads can be restored in some fashion. 

One way around this would be to move to a more modern forum stack (Discourse) that is better supported and that can be hosted someplace that is pretty resilient (e.g. you can one-click add a DigitalOcean droplet with Discourse, and get frequent backups and other things built-in). Discourse uses fixed URLs like /t/topic-name/26329 which I believe are better for wayback machine archiving. Moving entirely different forum software is a tough migration tho, and would change the UI on people which not everyone may love.

Another way around this is to move some content to a database like Airtable or a wiki so that fixed knowledge can be put someplace (like an archive of cards and their images), which would link back to threads where those were first mentioned. But all this is getting pretty off topic :)

 

Trash80toHP_Mini

NIGHT STALKER
Yep, time to get this page up to snuff for continuity's sake.

ExpanseSE/30 NuBus expansion box interface card:

View attachment 21952

PCI Interface Card for comparison:

Xpanse_N400_PCI-Interface-1.jpg

I wouldn't be surprised at all if the SE/30 expansion box weren't compatible with this interface and vice versa. 

Expanse N400 Motherboard paired with PCI Card above:

Xpanse_N400_Motherboard-1.jpg

Xpanse_N400_Motherboard-s.jpg

Well, that's about it for now, comments?

 

Trash80toHP_Mini

NIGHT STALKER
Another breadcrumb on the path to NuBus in SE/30 appears:

NuBus-SuperSlot-Expansion-Chassis.JPG

Hopefully this is how the ExpanSE/30 chassis works and offers a possible detour around the problems we're facing.

from: How the Macintosh II Nubus Works -  Second 1988 Mac Special Edition • B Y T E

NuBus research materials compilation at present:



Anybody got a lead on Inside Macintosh Volume V that's listed as indispensable in the CERN paper?

 
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