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SuperMac Spectrum/24 Project
Posted by: Phipli on 2022-09-09 05:51:35
Yes, I think I definitely do have the original card. ROM 1.0 1989, just as Trash has. If that is the case, I would need to find one of these oscillators for the higher resolutions as per the tables attached, correct? Mine currently Outputs 640x480 to my Apple Color Display.
Can you share a photo of the card?

If it only has one clock oscillator, then you should swap in a 64MHz clock like this one :


I've not seen an original Spectrum/24 - mine all have three clocks and a spare socket. 🙂
Posted by: MacOSMonkey on 2022-09-09 06:14:48
That oscillator is 64.000Mhz vs. 64.0000Mhz. The auction incorrectly states the frequency precision. But, any 64.000Mhz oscillator that is +/-100ppm should work fine. SuperMac originally used oscillators that were 64.0Mhz, but eventually improved the precision spec over time to 3 places.
Posted by: LaPorta on 2022-09-09 07:12:18
Sure, when I am home this evening I will pull it and we will have a look at it.
Posted by: Trash80toHP_Mini on 2022-09-09 09:02:10
Interesting, my crystal is the original spec: 64.0MHz

Forgot about the lack of pics, so now that mine has been freed:
______ Copystand lighting

Spectrum24-c-cs.jpg
Spectrum24-c-r-cs.jpg
Spectrum24-c-l-cs.jpg

Flash on copystand:

Spectrum24-c-fl.jpg
Spectrum24-c-r-fl.jpg
Spectrum24-c-l-fl.jpg

Spectrum24_Shots.10.2p-X.jpg
Posted by: Trash80toHP_Mini on 2022-09-09 09:16:58
Yes, I think I definitely do have the original card. ROM 1.0 1989, just as Trash has. If that is the case, I would need to find one of these oscillators for the higher resolutions as per the tables attached, correct? Mine currently Outputs 640x480 to my Apple Color Display.
Now you've got pics for comparison tonight as well as my screencap of everything SuperVideo but the custom setup window. Presumably you'll find someone swapped out the standard 64.0MHz crystal for 30.24MHz to support your monitor. While you're at it, order up the 24.00MHz Crystal to play with multisync displays to go with the OEM clock. That should prove interesting. 😉
Posted by: Phipli on 2022-09-09 09:21:58
Now you've got pics for comparison tonight as well as my screencap of everything SuperVideo but the custom setup window. Presumably you'll find someone swapped out the standard 64.0MHz crystal for 30.24MHz to support your monitor. While you're at it, order up the 24.00MHz Crystal to play with multisync displays to go with the OEM clock. That should prove interesting. 😉
I think the boards came with multiple clocks in the box and you put the one you wanted in the card. Your previous owner probably had a 16 or 19" Supermac monitor. LaPorta's probably had a 640*480 monitor.
Posted by: LaPorta on 2022-09-09 09:54:15
The interesting thing is my SuperVideo control panel allows me to select from 640x480 through 1024x768 (though I have never tested any of these since I just became aware of the control panel, and my attached Apple Color Monitor only does 640x480). They are not grayed out. Perhaps this means I have multiple oscillators? No idea, but tonight I will see. I do recall my card looking at least a bit different than Trash's.
Posted by: Trash80toHP_Mini on 2022-09-09 09:59:01
@Phipli ISTR reading it shipped with two crystals, the 64.0MHz can on my card and presumably the 32.24MHz can on LaPorta's because. The 24.00MHz oscillator was not included. Makes sense as the RGB was Apple's high end color display in that time frame. There was a ready market in the DTP workstation commonly set up with that monitor for spot color work in combination with a GS TPD or FPD for Page Layout.

If I get a chance I'll try to get the User Manual up so we'll all be on the same page. I can scan multiple pages to my email as a PDF.
Posted by: Trash80toHP_Mini on 2022-09-09 10:02:47
Perhaps this means I have multiple oscillators?
Might mean you have the 24.00MHz can after all? Doubtful as the 640x480 resolutions are not grayed out in the menu running under the 64.0MHz clock?

Please post pics of your card for comparison! 🙂
Posted by: LaPorta on 2022-09-09 10:21:36
When I get home this evening, I'll pop it and and we will have a look!
Posted by: LaPorta on 2022-09-09 10:37:22
Someone just put a SuperMac up for sale a minute ago:

https://68kmla.org/bb/index.php?threads/fs-nubus-video-apple-8â€Ē24-670-and-supermac-8â€Ē24-spectrum-pdq.42042/
Posted by: Trash80toHP_Mini on 2022-09-09 17:32:29
PDQ with sockets for four different crystals looks interesting, if not useful in this endeavor.
Posted by: Trash80toHP_Mini on 2022-09-09 17:42:41
Looks like I need to do it over using the bottom edge for registration as the page numbers are missing and there's plenty of room for cutoff at the top. Drat! If someone can repost this in the proper orientation that would be great for now. No biggie, but a PITA to have to rotate it every time. Can someone OCR the thing or should that wait until I post a clean, page enumerated version?
Posted by: Trash80toHP_Mini on 2022-09-09 17:47:09
Spectrum24-Unpacking.JPG
Posted by: LaPorta on 2022-09-09 18:04:00
Ok, well, my card certainly does look a whole lot different as yours as far as layout. It also looks to have the oscillator built-in, and a slot for an additional oscillator...and maybe solder points for two more slots??
Posted by: LaPorta on 2022-09-09 18:06:27
Thanks for the manual! Reposted:
Posted by: Trash80toHP_Mini on 2022-09-09 20:10:14
I've got it scanned into two files with chapter/page enumeration intact:
Cover to p.59
p.55 to End

Can someone piece them together and post it with OCR'd TXT?

Meanwhile:
Custom_Monitor_Configuration.JPG

I'm officially in over my head once again, but it looks like a fun ride coming up! ðŸĪŠ
Posted by: MacOSMonkey on 2022-09-09 20:10:51
LaPorta, your card is not a Spectrum/24. It is a ColorCard/24 (aka Calvin) without the daughter accelerator card (aka Hobbes) that goes on those 2 connectors. Also, it does not have enough video RAM to do 24-bit at 1024x768.

In addition, when you see the choice for 1024x768, it is because, at a base monitor resolution of 640x480, 1024x768 is a virtual desktop configuration. However, it should work in 8-bit mode at 1024x768. I think that might also work as a custom configuration on that card if you slot a 64Mhz oscillator.
Posted by: LaPorta on 2022-09-09 20:22:57
Thanks for that! Not sure how I didnt notice that before...

Can you stick more than one oscillator in there at a time?
Posted by: MacOSMonkey on 2022-09-09 20:50:46
You would have to experiment. You could try adding a socket to the 3rd position to see if it detected anything. It might or might not. Don't recall.
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