Techknight™ - SE/30 Greyscale MOD /w IIsi video card

are we sure this supermac card works in the se/30 as a riser?

lol

Micron's patent for SE/30 grey scale system:

http://www.google.com/patents/US5307083'>http://www.google.com/patents/US5307083

with circuit diagram for grey scale video board:

[attachment=0]US5307083-4.png[/attachment]

Or this website, which basically describes what you're tying to do (author's just using a different video card).

http://www.google.com/patents/US5307083

Hope you'll get it going!

Yea, thats the micron patent. the full schematic of the CRT video board is posted in the other thread. Ill probably end up duplicating that amplifier circuit.

Are you going to modify a stock board or manufacture a new one?

I'd like to know this.

Next we need to somehow clone an SE/30 grayscale video card to go with it.

c

Nope. just going to use the radius pivot IIsi card and modify it to drive the internal CRT.

First step in very many steps: Designing the extender card to bring the video card up into the bucket, without hacking anything or bending anything over 90-degrees.

This is a rough draft, no physical measurements taken, using the CAD's default board outline. Now, I will have to take offset and height measurements so i know what to make the board size, and eurocard positions.

it is a 4-layer board, with a ground plane in between the routing layers, this is to stop intersecting lines from cross-talking at the expense of slightly added capacitance. This is also dependent on the SE/30 PDS ground pin positions so this riser cant be used in anything else.

[attachment=0]expander.png[/attachment]

Crosstalk would be between all those lines running in parallel on the same layer as I understand it. You might want to throw alternate ground lines on there.

Have you tried fitting the RCPII/IIsi on top of the SuperMac Card already or does the installation really need that extra height? :?:

Cool stuff, techknight!

I dont heve a supermac card. Because it bends it 90 degrees and runs right into the floppy/HDD. I aint gonna do that, and im not cutting off connectors, adding left-angles and hacking all that crap. Screw that.

Ill roll my own.

NoPro.

Besides, once I have the riser in there, the pivot card should fit perfectly. And ill use its "pass-through" mode into another roll-my-own card that will cross over to LC PDS.

the LC PDS card i will probably have A24 through A31 as jumper holes, and of course the IRQ1/2/3 for Slots 9/A/B as jumper holes as well. This way, i can map the LC card slot E, swapping the high order address lines and jumpering the correct IRQ so itll map it to slot 9. the Pivot card has its own jumpers for 9 or A. its default at A. ill make the LC ethernet card 9.

Posting FWIW...Several years ago I made a riser for the SE/30 MB by stacking several 120 pin connectors together to raise an Asante NIC. THe thread is on Apple Fritter. It seems that over time many of the images seem to have dropped out of the thread. This shot shows several of the straight connectors stuck together:



Would this approach not achieve the same end? I think in this shot there were 2 or 3 straight connectors below the Asante to raise it above the floppy drive.

Von thank you for joining the party. That is a great idea/already done. Once tech knight gets the greyscale mod going that will help keep the 30 stock to the eye. I appreciate you migrating the info over.

I may never get this in mind as I'm kinda pinched these days but it will be awesome to see more SE/30's taking full advantage of their abilities.

are we sure this supermac card works in the se/30 as a riser?

Click to expand...

Electrically it works fine..

Techknight, I was also going to build an SE30 riser with two female sockets on it. It will allow us to use non-passthrough cards...

lol well i just got the motherload… so i am going to do some testing tonight with that supermac riser.

[attachment=0]Screen shot 2014-01-06 at 1.26.49 PM.jpg[/attachment]

this man ships fast!

A thought came to me..

I assume the CRT high voltage is generated from the vsync pulse and flyback xformer. (I dont have a circuit to confirm)..

We need to be VERY CAREFUL with the frequency of the vsync pulse, even a casual screen resolution change in the control panel could toast your analog board and crt.

I'm not an electronics person, but could you put some sort of buffer or filter to work like a fuse to keep it from blowing?

No no. Vertical sync has nothing to do with the high voltage. However... the horizontal frequency does. So, you have to keep this the same.

But once we have it driving the analog board from the video card, it doesnt matter anymore. As the pixel clock is generated in the card, not the mobo

Good to know. But still, inadvertently changing your resolution in the radius control panel, therefore changing hsync frequency could be messy?

Yes in theory. But if the line frequency goes too far out, you'll move outside the circuit resonance and HV will be poor, and the horizontal linearity will severely suffer, and will have foldover. (dont ask how i know this). This deflection stage is designed to operate at peak efficiency within the correct frequency range, give or take a few KHz.

However if the monitor ID bits are set correctly. "Apple 12" RGB" then we wont have any issues, it will go into 512x342 and stay there.

I have an Asante etheternet card for the IIsi and SE/30 and it looks basically like the Supermac version of the riser and of course fits. My question is can a direct 90 PDS female to male be made so the IIsi video card will fit inside without losing the hard drive and floppy area? I would be grateful to know if you could make one for me, only two tabs would need to be removed after that and it would fit stock (as I stare at mine pulled apart).

Of course I know you are still working on the greyscale mod which I would love at this point. At this point my SE/30 has my full attention.

It needs de yellowed and cleaned but works. Looking at getting some ram (cheap is always good).

Might put a bigger scsi drive in it.

Already have a apple caddy cd rom to put under it so I can do all that I need with it.

And as always great work on the project all! Thank you.

If I'm understanding you: ISTR going through that with techknight(?) and showing it wouldn't really work out the way it was envisioned, but there may be a better way to do it.

Isn't the 12 inch RGB resolution different from the internal CRT B&W resolution? 12 inch RGB is 512x384, 9 inch B&W is 512x342.

Isn't the 12 inch RGB resolution different from the internal CRT B&W resolution? 12 inch RGB is 512x384, 9 inch B&W is 512x342.

Click to expand...

I think that's correct, also I think my LC allows me to change the resolution from 512x384 to 560x384 to support the IIe card (which I really really want ).

I think that's why the 12" RGB has a slightly higher horizontal refresh rate compared to the compacts to account for the extra lines. Would the SE/30's board be able to cope with the extra 10% or so (IIRC)?

oohh. i knew my dislexia would get me eventually. I didnt see that.

I dunno, it depends on how far off the horizontal scanrate is compared to the original.

Dang, I missed that tooI

Nice catch, big.

or maybe we pull a minerAI and just change the freakin CRT. 1024x768, 9" greyscale from something.

nnnnnaaaaaa never mind forget i said that. we like originality? i mean, we like originality! well sorta ! )

The Pivot Card still gives you 151% more COLOR pixels of extended desktop. That's closing in on half a million pixels altogether!

That beats a measly 178,168 grayscale pixels through the periscope any day of the week and twice on Sunday. :approve:

So will the radius card does not allow for the correct resolution of the internal CRT then?

I guess that would make sense as there were not any external monitors with that resolution.

That would be why the Micron Xceed card was made just for that purpose then?

I don't really know what I'm talking about, but would it be possible to replace whatever part of the analog circuitry is responsible for the horizontal scan rate?

Also, just because the vertical resolution is different doesn't 100% mean that the horizontal scan rate is different. You also need to consider the number of invisible lines in the vblank region. For instance with VGA at 640 x 480, there are actually 525 lines, but 45 of them are invisible. So if the total number of visible + invisible lines is similar for 9" B&W and 12" RGB, it might still be OK.

I just looked it up, and the 9" CRT has a horizontal scan rate of 22.25 kHz, while the 12" RGB has a horizontal scan rate of 24.48 kHz. That's a difference of about 10%, which is a little better than the difference in the vertical resolution, but not by much. Hmmm.

Any r/l/c networks for the yoke would have to be changed to suit the freq. Maybe not within 10% though.

I do know the analog board wont do 640x480. I tried that and the horizontal linearity was way out and had barkhausen noise along with severe foldover.

The vertical, and crt modulation was fine. Its the horizontal deflection that became a problem

so are you pretty sure 512x384 is possible?

Only one way to find out...