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

[uniserver]

I am starting this thread so its easier to keep track of all these nifty SE/30 mod's all going on.

Basically Techknight is looking at modding the SE/30's video board to allow greyscale mode.

This mod will be used in conjunction with this IIsi video card + this adaptor.

http://www.ebay.com/itm/SE-30-Hack-Project-Radius-Color-Pivot-IIsi-Video-Interface-Card-Apple-Mac-/151201983898?pt=US_Vintage_Computing_Parts_Accessories&hash=item2334572d9a&_uhb=1

http://www.ebay.com/itm/SE-30-Hack-project-SuperMac-PDS-Angle-Riser-Apple-Mac-/310835137053?pt=US_Vintage_Computing_Parts_Accessories&hash=item485f37ca1d&_uhb=1

 

[uniserver]

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

lol

 

[genie_mac]

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!

 

[techknight]

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.

 

[CC_333]

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

 

[techknight]

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

 

[techknight]

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]

 

[Trash80toHP_Mini]

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!

 

[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.

 

[Trash80toHP_Mini]

NoPro.

 

[techknight]

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.

 

[Von]

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.

 

[Macdrone]

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.

 

[tsillay]

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

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...

 

[uniserver]

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!

 

[tsillay]

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.

 

[olePigeon]

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?

 

[techknight]

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

 

[tsillay]

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