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SuperMac Spectrum/24 Project

Trash80toHP_Mini

NIGHT STALKER
Thanks for popping back in, bud!

I spent some time digging around for that thread, to no avail. Apparently I'm just not good with the search engine terms today.
I forgot, what's the switch on Google that limits searches to the MLA? Their bot has scraped up whatever it's wanted here since the dawn of time. Searching just this site a/o the archives using Google, DuckDuckGo etc. could be a workaround for searching lot of our broken linkage and topics?

Search methods like that on current engines might make for a good topic somewhere?
 

Phipli

Well-known member
The Spectrum 24 Series III doesn't show the custom resolution option in the drivers I tested, so sadly that is the end of that experiment, unless I can work out another way of adding resolutions.

Ah well.
 

Trash80toHP_Mini

NIGHT STALKER
SwitchRes I've heard much about, but never tried. My card is flat out, baseline Spectrum 24 with a redonkulous amount of customization available for virtual desktop, but limited to something like 1024x768 output or less on the connector by the RAMDAC as I understand it.
 

Phipli

Well-known member
I suspect that SwitchRes wouldn't work - I anticipate that the Supermac control panel sort of loads new microcode into the card itself... SwitchRes would need to be designed to specifically work with the hardware in that card.
 

Trash80toHP_Mini

NIGHT STALKER
First part of @Gorgonops great rehash of old thread:
Anyway, FWIW, my vague memory of the takeaway from that discussion was that the architecture of the 24 bit versions of these cards (the 3MB RAM models) is essentially as if you stacked up in parallel three 8-bit 1MB cards. IE, the issue with Trash's dream of outputting the mega-high (virtual) resolutions that in terms of raw pixel count could fit in 3MB is the output circuitry can't "chain" the memory on those three planes together. So, for instance, even if you stuck an oscillator in there that ran fast enough for a 1920x1080P mode's pixel clock (and somehow didn't melt the RAMDACs, given their maximum rated clocks are only a little over half what's needed for that) because the math tells you that doing 8-bit at that resolution only requires 2MB (a little less, actually) of RAM that card still won't be able to push it because in 8-bit mode it can't access more than 1MB.

Middle part, heart of the info:
Technically, yes, the bandwidth is there, IE, at 1024x768@24 bit it's throwing more *memory* out the back door per second than it would be at 1920x1080@8, but it can't throw that many *pixels* out. If you wanted to rip off the RAMDACs that are there and design new output circuitry that takes the three color planes for a 24 bit mode into a latch and then clocks them out as three 8-bit pixels through a faster RAMDAC (essentially clock-tripling the card to trade depth for pixels) then I guess that would probably be... possible? But it'd come at significant price. I don't know how this card presents the three bit planes to the mac,

Tangentially interesting part:
IE, does it present the 24 bit pixels "packed" (IE, it fits 4 pixels into three linear 32 bit words of memory space), or does it align them as one pixel per 32 bit word? (It just doesn't have bits to store the extra byte. Modern "24 bit" video systems of course typically use 32 bit memory and can use the extra byte for "other things", like gamma, transparency, z-buffer, whatever.) If it's not packed then your 8-bit mode won't be linear anymore and you'll have to deal with that in software. Quickdraw might not support such a monstrosity.
Folks have been lamenting the inability of some high end cards to output 8 bit for gaming. Might shifting to 32 bit memory be a reasonable explanation for that?
__________________________________________________

Back on topic: Forgot all about the X/Y pixel limitation aspects for wide screen output for this card!

720x480 AKA 480p, the native resolution of DVD's might be a possible output resolution for this card's hardware?

If so, conversion to HDMI inputs of current 1080p displays and TVs from DVD players are scaled automatically by them. VGA to HDMI converter is an inexpensive little doohickey I've been using with a scaler for oddball Mac resolutions output by proprietary VidCards for SE and such on the TV ext to my hack hutch.

Sticking point here might be flexibility of a VGA converter. Whatcha think, Eudi?
 

Trash80toHP_Mini

NIGHT STALKER
@Gorgonops It's looking like this should be the target resolution? I was worried by not finding 720x480 in the VGA tables.

Wikipedia:

854 × 480 (FWVGA)​

FWVGA is an abbreviation for Full Wide Video Graphics Array which refers to a display resolution of 854 × 480 pixels. 854 × 480 is approximately the 16:9 aspect ratio of anamorphically "un-squeezed" NTSC DVD widescreen video and considered a "safe" resolution that does not crop any of the image. It is called Full WVGA to distinguish it from other, narrower WVGA resolutions which require cropping 16:9 aspect ratio high-definition video (i.e. it is full width, albeit with considerable reduction in size).

The 854 pixel width is rounded up from 853.3:

480 × 16⁄9 = 7680⁄9 = 8531⁄3.
Since a pixel must be a whole number, rounding up to 854 ensures inclusion of the entire image.[75]

In 2010, mobile phones with FWVGA display resolution started to become more common. A list of mobile phones with FWVGA displays is available. In addition, the Wii U GamePad that comes with the Nintendo Wii U gaming console includes a 6.2-inch FWVGA display.

Such might get through VGA conversion, but half scaled 1080p would be 960x540? Color me a bit confused. :rolleyes:
 
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Jamieson

Well-known member
How (or where) are the custom monitor profiles being defined? I have SuperVideo 2.7.5 installed and it works with my Spectrum/24 III card, but I don't see where to enter the custom monitor types.

Curious to see if the card could be made to support 1280x1024, even if in 4 bit mode. Using the 80MHz pixel clock I was able to come up with some timings that fall within the H and V frequency ranges of my LCD monitor. Granted, the H front and back porch and Hsync pulse is pretty short, but maybe an LCD doesn't need that time to sweep a beam back to the starting point.
 

Phipli

Well-known member
How (or where) are the custom monitor profiles being defined? I have SuperVideo 2.7.5 installed and it works with my Spectrum/24 III card, but I don't see where to enter the custom monitor types.

Curious to see if the card could be made to support 1280x1024, even if in 4 bit mode. Using the 80MHz pixel clock I was able to come up with some timings that fall within the H and V frequency ranges of my LCD monitor. Granted, the H front and back porch and Hsync pulse is pretty short, but maybe an LCD doesn't need that time to sweep a beam back to the starting point.
Its in this window (it says double click). I'm not sure if you need a clock in the empty socket for it to work. I had trouble finding it when I tried, I need to come back to it.
 

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Jamieson

Well-known member
On my setup I show three oscillators present (30.24, 64, 80) but the line about Double-Click here is not present. If I double click on any of those items nothing happens. I'll try adding an oscillator to the empty slot and see if that "unlocks" anything.

dialog.png

I was able to find the "Spectrum/8 III" manual online. Does anyone have a link to the PDF for the "Spectrum/24 III" manual?
 
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Phipli

Well-known member
On my setup I show three oscillators present (30.24, 64, 80) but the line about Double-Click here is not present. If I double click on any of those items nothing happens. I'll try adding an oscillator to the empty slot and see if that "unlocks" anything.

View attachment 42498

I was able to find the "Spectrum/8 III" manual online. Does anyone have a link to the PDF for the "Spectrum/24 III" manual?
I'm in the same situation as you, I gave up at the time because I couldn't find a cheap 80MHz clock (all excessive postage from abroad) and wasn't entirely sure the Spectrum 24 III supports the custom resolutions feature, based on the extract I previously mentioned in an old post.

I couldn't find the Spectrum 24 III manual online sorry. Might be worth asking if anyone can scan a copy in a new thread. The 8 bit one will be extremely similar though.
 

Jamieson

Well-known member
In SuperVideo 2.7.5 with a Spectrum/24 III there are only four monitors shown: SuperMac High-Res RGB @ 60Hz, SuperMac High-Res @ 75Hz, Apple RGB, and NTSC RGB. No mention of a PAL monitor, or Apple 15" portrait display. Maybe these options do appear in the list when the appropriate oscillator is installed.

When I select the NTSC option the utility warns me about not having an oscillator installed, which suggests that the hardware is capable of 1) determining the oscillator frequency and 2) communicating that info to the driver. I'll scrounge around for some oscillators and try them out on the card and see what happens.
 

MacOSMonkey

Well-known member
If you attempt to set a video configuration on Spectrum/24 with no related oscillator installed, you will get no video output. (Hence, the warning.)
The stock frequencies are:
64Mhz: SuperMac 19" 1024x768 60Hz
80Mhz: SuperMac 19" 1024x768 75Hz (but the Spectrum/24 only does 60Hz, I think -- there are other hardware limitations on the Gen 1 board that were upgraded with the switch to SMT01 (SMAC Gen1 video controller)/BSR02 (SMAC Bit Shift Register) on the Spectrum/24 Series III board to use with (then) newer 1024x768 75Hz Trinitrons vs. the off-the-shelf TMS/TI part (maybe) on the Spectrum/24.
30.24Mhz: Apple RGB 13" 640x480

As for the other frequencies, they are shown above by OPs -- 14.31818 for NTSC, 17.73 for PAL, etc. (neither of these is broadcast standard, btw, but they work)

Within SuperVideo, the Option Key may get you into Hogwarts. Hold down the Option Key and click on the Monitor config icon, then scroll to the bottom of the list and look for "Custom" -- maybe it will work, or maybe it won't. Definitely on Spectrum/24, and maybe on Spectrum/24 Series III. Also, Option+SuperMac S will show you the development team. Just don't mispronounce "Diagon Alley."
 

MacOSMonkey

Well-known member
There was also a 75Mhz 1024x768 Hitachi Monitor with Dot Shadow Mask (vs. Sony Trinitron Aperature Grill mask technology) -- same video timing, but a cheaper alternative with slightly fuzzier pixels vs. the square/sharper ones on more expensive Trinitrons.
 

MacOSMonkey

Well-known member
Actually, I think there does have to be an oscillator in the extra slot in order to enable custom configs in SuperVideo.
 

Trash80toHP_Mini

NIGHT STALKER
I didn't think any but the first rev. Spectrum/24 did custom resolution setup? That was at the dawn of time before Apple's silly "flicker free" resolutions were spec'd all over the place in terms of refresh rates and set in stone tablets on Mac VidCards. Once that was done, the extreme flexibility of the first rev. Spectrum/24 was dropped in later versions of the series as it was no longer needed, no?

I had screencaps of the setup dialog boxes for inputting the requisite numbers in the previous thread.
 

MacOSMonkey

Well-known member
The 75Hz era/1024x768 era brought a nicer viewing experience for users, but, as long as there was an open oscillator socket on the board, there was support for custom timings. Superquently, SuperMac went to 1152x870/21" monitors and also supported offerings from other vendors, including Apple and RasterOps. Anyway, boards like Spectrum/8, Spectrum/8 Series III, Spectrum/24 and Spectrum/24 Series III were definitely programmable. But, whether or not the configuration worked was up to the user. There was a Hypercard Utility called "Video Helper" to help users figure out their timings. I think there was also a clock synthesizer in later boards that was capable of multiple frequencies -- PDQ and Thunder, I think. I will check my Thunder/24, but yes, I think it was dropped/de-emphasized over time. However, early-on, it was a competitive selling feature.
 

Jamieson

Well-known member
With the oscillator socket empty I'm unable to get into a custom setup screens. This is with SuperVideo 2.7.5 Tried multiple combinations of Option keys, etc. I do the see the developer list though. With the oscillator socket populated (I think I used 50MHz just because that's what I had around) my IIci doesn't boot at all. It's OK, the Spectrum/24 III is still a solid card for 1024x768 in 8-bit and 24-bit modes.
 

Trash80toHP_Mini

NIGHT STALKER
I was able to find the "Spectrum/8 III" manual online. Does anyone have a link to the PDF for the "Spectrum/24 III" manual?
Nope. ;)

54-55_Spectrum24.jpg
56-57_Spectrum24.jpg
58-59_Spectrum24.jpg
60-61_Spectrum24.jpg
62-63_Spectrum24.jpg

Didn't include 3 lines of text about deleting configs on the next page, but there you go!

All I've seen or read here has to do with baseline SuperVideo acting as a Monitors Control Panel Replacement. If you can get into Custom Monitor Configuration you may be good to go with later versions of the Spectrum/24 series?

For output, the resolution is required to be within the capabilities of the RAMDAC which @trag defined somewhere. Input the timing parameters for any given resolution for "My Monitor" and SuperVideo calculates the required crystal freq.

If you can't do that in later versions of SuperVideo, all that's left would be the question of setting the config up in the older version and hope the "My Monitor" configuration can be imported and selected in the later versions when spec'd crystal is installed.

Dunno if that'll work or not. I've got the official VGA timings spreadsheet somewhere, but I'm NDA'd. Don't have 720p, which is the unicorn hunt as it stood last time I re-visited this project.

Hope that does it, no time for anything else before work today.
 
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Phipli

Well-known member
Nope. ;)

View attachment 45816
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View attachment 45820

Didn't include 3 lines of text about deleting configs on the next page, but there you go!

All I've seen or read here has to do with baseline SuperVideo acting as a Monitors Control Panel Replacement. If you can get into Custom Monitor Configuration you may be good to go with later versions of the Spectrum/24 series?

For output, the resolution is required to be within the capabilities of the RAMDAC which @trag defined somewhere. Input the timing parameters for any given resolution for "My Monitor" and SuperVideo calculates the required crystal freq.

If you can't do that in later versions of SuperVideo, all that's left would be the question of setting the config up in the older version and hope the "My Monitor" configuration can be imported and selected in the later versions when spec'd crystal is installed.

Dunno if that'll work or not. I've got the official VGA timings spreadsheet somewhere, but I'm NDA'd. Don't have 720p, which is the unicorn hunt as it stood last time I re-visited this project.

Hope that does it, no time for anything else before work today.
If you look back through the thread I had a punt at the 720p timings. I just couldn't get the window open to enter them, and couldn't find a cheap 80MHz crystal.
 
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