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Help Identifying Mystery LC PDS Video Card

maceffects

Well-known member
I ordered an LC with what I assumed was a co-processor card from a birds eye photo.  However, once I got it, it appears to be a video card.  The only marking is on the main chip but Googling the sticker revealed nothing.  It is a DB-9 style monitor connector and has 4 hm53461zp-12 video memory chips.  Anyone see one of these before?  Is it a single page display card?

IMG_6445.jpeg

 

trag

Well-known member
The strange thing is that the DB-9 connector is removable. 
I bet there was a Mac model with an LC PDS slot that needed a backplate and wiring harness to reach the backplane.   Maybe the Classic II or Color Classic.

The removable DB-9 connector would have allowed the connection of a harness and back plate.

 

Trash80toHP_Mini

NIGHT STALKER
Sounds like a plan.

Doubtful you'll need drivers as they should be in the Declaration ROM. I can only recall a single instance where drivers were required for basic function of a video card and don't recall for sure if that one was Slot Manager/DeclROM architecture. Drivers in DeclROM are required for any VidCard to be the primary display on boot after POST, else you'd never see the  :huh: icon indicating successful hardware check. Happy Mac screen indicating boot drive located would only be seen at some point after extensions/drivers were loaded, the process of which would be on a blank screen. I've never seen that to be the case and I have or have had and played with a very large number of VidCards.

Frantic driver hunts to get a card that doesn't appear to work at all would in response to output/sync rate/display mismatch as I see it, not a lack of driver support. Drivers add features, not the basic functions necessary for any VidCard to support a Primary or Single Display.

That's how I see it of course, others may disagree.

 
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Maurice

Member
I think I found the Data Sheet for the Chip (ICD2042) on your Circuit Board, it's a Dual VGA Clock Generator. It supports IBM VGA, XGA and 8514 graphic applications. The Data Sheet I found is from Cypress.

You also have a Crystal Oscillator (silver can) on the Circuit Board which is used to help generate vertical and horizontal frequencies for the CRT Monitor.

The large square Chip is a Field Programmable Gate Array (FPGA). Graphic Card Companies would program this type of chip as a Graphics/Video Controller.

It looks like you have a total of 128K Bytes of Memory, which means the Video Card only has enough memory for a Monochrome Display (Black & White).

Radius made a (FPD) Full Page Display Video Card (640x864) like yours around 1991 for the Macintosh Classic. See attached Image with square Chip and four vertical Memory Chips.  

Radius also made a (FPD) Full Page Display Video Card  (640x864) for the Macintosh LC around 1991. I never found a picture for it.  

Is there any numbers or letters on the back of your Circuit Card?

Classic Front.jpg

 
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