pcamen
Well-known member
Yes, the manual is on VintageApple.org:
https://www.vintageapple.org/macbooks/pdf/Micron_Technology_Xceed_SE-306-48_1989.pdf
https://www.vintageapple.org/macbooks/pdf/Micron_Technology_Xceed_SE-306-48_1989.pdf
Thanks much, pcamen. I figured the user manuals were out there somewhere, but this one's a much better find. Brain's all but shut down ATM, don't remember seeing that tech doc before. I wonder if I got the Development Docs/Technical Info for the Color30 there too? Pretty sure it was somewhere else, a link to that would be good, gang. []Yes, the manual is on VintageApple.org: https://www.vintageapple.org/macbooks/pdf/Micron_Technology_Xceed_SE-306-48_1989.pdf
Not backwards at all, if you look at it the other way around! [] You're syncing the video card to the VSYNC output from the Logic Board connector, not the A/B. HSYNC is carried along for the ride on the harness and passed with VSYNC to the A/B from the Color30, with the HSYNC signal used by Color30.Well I was thinking along the side of driving the analog board from the video card, not sync the video card to the analog board. Seems backwards to me.
Back to car analogies, it's a rare high performance vehicle modification akin to Shelby modified Mustangs. I don't know how many were made, but nothing like a sizeable percentage, if even a significant percentage of SE/30 production. It's not really in the unicorn class where a Shelby Cobra would be. Micron had a patent on the Xceed GS mod, so no others became available for the niche SE/30 market. The cards were inexpensive enough for the time, but use of a second, Color Screen possibly topped the list of reasons to buy any Micron card, especially so the 1024x768 capable versions....hmmm, is this Micron Xceed Grayscale Kit so much special? What makes them so rare and pricy at all?
I agree, I could make an adapter that would allow a LCD to fit in and look stockish but, the real appeal is the original CRT and Grayscale. I have zero interest in external video either.Personally, I only want internal grayscale and the only modification I'm comfortable with is one that keeps the original motherboard and CRT.
Is this a correct summation of the problem:
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The SE/30 has only an 8 bit data path to the VRAM (D24 - 31).
This requires byte-wise writes to the VRAM, instead of using the 680x0's normal 32 bit data path. This uses a feature of the 680x0 chips called Dynamic Bus sizing.
The 68030 uses a different control signal scheme to signal/setup Dynamic Bus Sizing than the 68040.
...
Seems disappointing to me that the data path to VRAM is only 8 bits wide. Aren't there two VRAM chips? Are they only 4 bits wide each?