I have ordered 4 chips, and in about two weeks I will test the card. Thank you very much for yours responses!

Horun wrote on 2025-05-22, 01:09:

Ahh ! guess I should have looked over other cirrus vlb's before posting above. Odd that the 74LS245's were socketed...
here is VLB Ref design schematic from Cirrus 1994Tech Ref...there is an ISA one in that book too

Do you also have the schematics for the GD5428 and GD5430? It would be quite useful for me.

EduBat wrote on 2025-05-22, 19:31:

Do you also have the schematics for the GD5428 and GD5430? It would be quite useful for me.

The schematics for the 5426 and 5428 are identical. The common data book scan on the internet is a collective data book describing the whole family of PC-type graphics chips, the 5420, 5422, 5424, 5426, 5428 and 5429. The differences regarding schematics are minor.

The 5430 series on the other hand is clearly different. Most notably it's the first Cirrus chip that provides a 32-bit data bus towards the host CPU. I don't have 5430 schematics at hand.

mkarcher wrote on 2025-05-22, 19:56:

EduBat wrote on 2025-05-22, 19:31:

Do you also have the schematics for the GD5428 and GD5430? It would be quite useful for me.

The schematics for the 5426 and 5428 are identical. The common data book scan on the internet is a collective data book describing the whole family of PC-type graphics chips, the 5420, 5422, 5424, 5426, 5428 and 5429. The differences regarding schematics are minor.

The 5430 series on the other hand is clearly different. Most notably it's the first Cirrus chip that provides a 32-bit data bus towards the host CPU. I don't have 5430 schematics at hand.

Thanks for the clarification, much appreciated.

EduBat wrote on 2025-05-22, 19:31:

Horun wrote on 2025-05-22, 01:09:

Ahh ! guess I should have looked over other cirrus vlb's before posting above. Odd that the 74LS245's were socketed...
here is VLB Ref design schematic from Cirrus 1994Tech Ref...there is an ISA one in that book too

Do you also have the schematics for the GD5428 and GD5430? It would be quite useful for me.

Yes the Ref design schematic for GD5430/40 series is in a Alpine Tech Ref from 1995 (see: http://www.bitsavers.org/components/cirrusLogic/graphics/)
here is just the VLB ref schematic, there is also ISA and PCI ref schems in that book....

Horun wrote on 2025-05-23, 00:46:

EduBat wrote on 2025-05-22, 19:31:

Horun wrote on 2025-05-22, 01:09:

Ahh ! guess I should have looked over other cirrus vlb's before posting above. Odd that the 74LS245's were socketed...
here is VLB Ref design schematic from Cirrus 1994Tech Ref...there is an ISA one in that book too

Do you also have the schematics for the GD5428 and GD5430? It would be quite useful for me.

Yes the Ref design schematic for GD5430/40 series is in a Alpine Tech Ref from 1995 (see: http://www.bitsavers.org/components/cirrusLogic/graphics/)
here is just the VLB ref schematic, there is also ISA and PCI ref schems in that book....

That's great, many thanks!