Data General Nova 3 and 6045 Drive Questions
Mark J. Blair
nf6x at nf6x.net
Sun Jun 12 00:10:00 CDT 2016
> On Jun 11, 2016, at 22:00, Bruce Ray <Bruce at Wild-Hare.com> wrote:
> DG Model 6045 disk drive heads 0 and 1 are the removable platter, heads 2 and 3 are the 'fixed' platter. As you said, the controller memory address and sector/sector/count values are set to 0 by the IORESET pulse, so a read operation (STRT pulse) will start the reading of the bootstrap into low memory from the removable disk.
Excellent! That makes sense.
Ok, studying the documentation scans I have some more, I think I plugged the hard drive interface cable into the wrong connector when I reassembled the system after moving it. Hopefully I didn't damage anything! On the backplane, there's a terminator on the bottom rear connector (P3 I/O bus, I think), and there's another card edge installed behind the top rear connector (P4, disk drive interface, I think). I had the disk drive cable on the inboard add-on connector instead of the top backplane connector (P4). I think that was wrong!
But studying the documentation, I see that P4 is hard-wired to slot 10. However, the cards might be installed incorrectly in my system. I have plugged in:
Slot | Part Number | Description
12 | 107-000116-08 | DGC NOVA QUAD MULTIPLEXER
11 | 107-000187-16 | DISK CARTRIDGE CONTROL DGC NOVA
10 | |
9 | |
8 | |
7 | |
6 | |
5 | |
4 | 107-000151-19 | DGC NOVA CASSETTE I/O
3 | | 128K MOSTEK MEMORY
2 | 107-000621-01 | NOVA 3 TRIPLE OPTION
1 | 107-000539-05 | NOVA 3 CPU
I think that I need to both move the hard drive cable to P4 at the top rear of the backplane, and move the disk controller card to slot 10. Does that sound correct?
I don't know what that expansion card edge is for yet, and I can't get to it easily right now with the chassis in the rack. Maybe it's wired to the Cassette I/O card? I should take some detailed pictures to post and discuss tomorrow.
That Cassette I/O card looks interesting to me, and I wonder if there's any chance that I might find the tape transport that goes with it.
> Contact me off-list regarding the documentation...
Will do! And thanks for your indispensable help with my system last time I gave it some brain bandwidth.
Now I'm off to try and figure out what baud rate my console is strapped for, which I wasn't smart enough to write down last time I worked with the system.
Mark J. Blair, NF6X <nf6x at nf6x.net>
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