SuperMac Spectrum/24 Project

[Trash80toHP_Mini]

I've located the VESA association's Video Timings Generator spreadsheet and backed it up to SD and my current daily driver. But I'll have to get set up to run it from the Pavilion DM-1 Netbook where I was playing with it for this project ten years ago. NDA'd, so I can't upload it anywhere, don't ask.

I'll work at wringing 800x600@60Hz timings out of it as soon as I get a chance.

 

[mg.man]

FYI, there's a Spectrum/24 III (according to the lisring) up on Mercari (via Buyee) :

https://buyee.jp/mercari/item/m40297367179

 

[Phipli]

@LaPorta
I used to make these things :



Two SMD clocks in the form factor of a DIP14 that you can toggle between. I made them for an easily switchable overclock on my Acorn A3010, or for a IIsi or Quadra 700 with full size clocks.

I was considering adding one to a graphics card for resolution options (powered down to switch).

With a 64MHz clock in the empty socket you should be able to get 640*480@24bit and 1024*768@8bit.

 

[Phipli]

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.

Liking the Calvin and Hobbes reference

Also note Spupermac replaced the TMS with an SMT

 

[MacOSMonkey]

Yes - the ColorCard/24 moved forward to SMT01 and was the cheaper Apple 13" form-factor companion to the Spectrum/24 Series III (also SMT01), code-named Easy (board) and Rider (plug-in accelerator).

 

[LaPorta]

So there is a separate card missing that plugs into mine? What did it do?

 

[Phipli]

So there is a separate card missing that plugs into mine? What did it do?

I think it was an optional graphics accelerator so not missing, but more "not purchased" . Adverts from the time seem to say the colorcard/24 was quickdraw accelerated anyway, so perhaps it was a DSP board for speeding up photoshop? Had a quick look but couldn't see a review because I was getting too many advert hits.

 

[Trash80toHP_Mini]

I usually slog through PDFs of MacUser issues from the period of the product for reviews, shootouts of competing products, intro blurbs and adverts for specific product info. From there I go on to comparing the MacWorld issues, but that pub is watered down to baseline consumer level, while MacUser is much more technically oriented.

I wish someone would create a PDF with the TXT of the entire MacUser archive for keyword searches.

 

[LaPorta]

The good thing is that all I am using this card for is to drive my Apple M1212 Color Display @ 640x480 anyway, so it is perfect for that. I use my Radius Paintboard Li for the 124x768 LCD .

 

[Trash80toHP_Mini]

@beachycove have you still got this card? Hopefully it's the twin of my card documented on the previous page. If so, what ROM and software versions have you got for yours?

Who else out there has one?

 

[MacOSMonkey]

So there is a separate card missing that plugs into mine? What did it do?

It was a GAL-based accelerator board. Without it, the card is a standard 24-bit 640x480 frame buffer with all of the typical SuperMac features, as shown above. Fun to see the old ad.

 

[Phipli]

It was a GAL-based accelerator board. Without it, the card is a standard 24-bit 640x480 frame buffer with all of the typical SuperMac features, as shown above. Fun to see the old ad.

Do any Supermac cards support bus mastering? Can you accelerate a framebuffer card from a Thunder or anything like that?

 

[beachycove]

I still have it (Spectrum 24/ V, as I recall), but we moved across the country last year and my stuff is still in storage, some of it being rather deep in storage, so I can’t really answer your question, Trash. Sorry.

I am going to start excavating said storage and selling much of my old Mac gear off in the new year. I just no longer have the room to set it up and enjoy it. I have room these days for an SE/30 and not much more.

 

[Trash80toHP_Mini]

I'm beginning to wonder if I'm the only one who has one of these dinosaurs?

 

[MacOSMonkey]

I'm beginning to wonder if I'm the only one who has one of these dinosaurs?

I searched for you and found a prehistoric floppy. VideoHelper 1.0 is a whimsical tool from 1988 that helped power-users calculate oscillator frequencies and other values. It also allowed users to archive information for custom monitor configs for entry into SuperVideo. It should work in HyperCard 2.0ish, but YMMV. Notably, it has a bunch of information about limitations with the TMS-based designs.

 

[Trash80toHP_Mini]

Thanks.

At this point I'm hoping experimentation with my card might help in later cards. As the custom ASICs designs were almost without doubt based upon the capabilities (extended to TPD support) of the TMS34061 Video Controller. TI didn't happen to be the OEM SuperMac's proprietary ASICs? As for Apple, Ti would have likely have been the OEM with the ASIC development outsourced to them?

I’d be surprised if the later SuperMac cards that were based on custom silicon just implemented a 34061-compatible portion to stay compatible with the old way to generate the video signals… I doubt they do.

Not so doubtful here. I have some hope that TI expanded upon TMS34061 capabilities, nothing else makes much sense. Why reinvent the wheel? Add metal band tires to a chariot wheel and it'll support higher performance with increased durability. Removing programmability would be akin to deletion of the metal banding whilst delivering more horsepower with proper harness technology.

Thinking would be that bumping an existing controller design to TPD output capability would be the least complicated, lowest cost development option for a quick second gen product intro?

By comparison, total redesign of a controller in such a short development cycle is clipped neatly by Occam's Razor?

VideoHelper 1.0 is a whimsical tool from 1988 that helped power-users calculate oscillator frequencies and other values. It also allowed users to archive information for custom monitor configs for entry into SuperVideo.

Sounds like a plan might be taking shape here? A SuperVideo Control panel with customized config embedded might be used in second and maybe third gen versions of the Spectrum/24. Drivers loaded from disk can override/add function to baseline drivers required in DeclROM spec.

 

[MacOSMonkey]

Well...I had trouble getting the HC2.0 version to run under SheepShaver. The disk had old and "new" versions, so I took the new one (which was just a converted version for HC2.0). The old version appears to be same, and works with HyperCard 1.2.5, including on SheepShaver. Also, the stack had an old test card in it that had variant 19" info, so I fixed it for Spectrum/24. It should be easier to use the attached one with matching HC1.2.5 environment. Good luck shaving Ben Hur with Occam's Razor.

Otherwise, while general specs are always good to know, what matters is the specific implementation. Early SuperMac cards, like Spectrum/24 1.0 implemented minimal slot manager support. In later SuperMac boards, there was the addition of "VDI" (Video Driver Interface) support, which theoretically allowed for certain additional/external configurability in conjunction with SuperVideo 3.0. However, the support also had to be in the firmware, and the earlier boards absolutely did not include it. Also, there was more than one version of the VDI implementation, and it may have started with the 2nd gen PDQ boards or the Thunder boards -- around that approximate timeframe. But, AFAIK, as of mid-1992, it was never really tested or used for anything, because SuperVideo 3.0 did not ship until later.

Note - the attachment is still not right - fixing it... one sec.

 

[MacOSMonkey]

OK - the time limit expired. Here is HC1.2.5 version that seems to be working OK. I have also added some screenshots. Let me know if there are any issues, and I will try again, if needed.

The Main Screen:


The Oscillator Calculator:


The Saved Monitors Section (don't delete or rename the Spectrum card):


Note that at the end of the "Monitor" cards, there is a Timing Card. It isn't fully implemented, but does have built-in pop-up help showing the timing formulae.

Here is an example from the Help Section:


A Minor Miracle That These Images Still Exist:

 

[MacOSMonkey]

I dug through my old junk boxes and was able to find and recommission a Spectrum/8 Series II ("Spectrum C") board (8-bit, 1024x768) with the original 1.0d14 ROM ("d" stands for "development," as you may know). It has 3 oscillator sockets, comes with 30.24Mhz (Apple 13") and 64.0Mhz (SuperMac 19" 60Hz) oscillators pre-installed. It is customizable based on built-in configs of: 640x480 (13", NTSC, Multisync), 1024x768 (SuperMac 19"), 768x576 (PAL), 800x600 (SuperMac 16" and Seiko), etc., with a max width of 1024 and max oscillator frequency of 64Mhz. Multisync mode uses 24Mhz, 16" uses 50Mhz (SuperMac) or 44Mhz (Seiko). I popped in a 55.00Mhz oscillator in the spare socket, the board detects it, and it shows up in SuperVideo. The monitor is an Apple Multisync 15 that supports SVGA/800x600, so I just need a 40 or 50Mhz oscillator to make it work at 60Hz or 72Hz vertical.

 

[Phipli]

The monitor is an Apple Multisync 15 that supports SVGA/800x600, so I just need a 40 or 50Mhz oscillator to make it work at 60Hz or 72Hz vertical.

For any experimenting with clocks is it worth getting one of these and knocking up a circuit?

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The output is 3.3V so you'll need something fast like a SN74AHC1G08DBV to level shift the output to 5V plus an AVR or similar to set the speed.

This might be overkill