The info on VRAM in the Duos and other PBs from the era is poorly documented.
I'm not certain that upping the VRAM is going to help in and of itself. I suspect the RAMDAC in(?) the CSC Video Controller is at its limits doing what it does. The Duos used the GSC controller through the October 1994 of the 250. The 270c introduced with the 250 that month switched to the CSC controller, which remained unchanged through the 2300c/5300xx rollout in Aug of 1996. The 2300c retained CSC while the ECSC was used in the 5300 series and later 1400 series.
I think it was MadDog over on 'fritter who was trying to do increase the VRAM of the 2300c, but I think he was planning on stacking the extra VRAM on top of the standard chips. I do know that he successfully replaced the CSC Video Controller of the 2300c with the ECSC Video Controller from a 1400. That's on my list for the SuperDuo and I'm fairly sure doing so is a given for making use of additional VRAM in the 2300c.
Dunno for sure though, that was a long time ago.
I'm not certain that upping the VRAM is going to help in and of itself. I suspect the RAMDAC in(?) the CSC Video Controller is at its limits doing what it does. The Duos used the GSC controller through the October 1994 of the 250. The 270c introduced with the 250 that month switched to the CSC controller, which remained unchanged through the 2300c/5300xx rollout in Aug of 1996. The 2300c retained CSC while the ECSC was used in the 5300 series and later 1400 series.
I think it was MadDog over on 'fritter who was trying to do increase the VRAM of the 2300c, but I think he was planning on stacking the extra VRAM on top of the standard chips. I do know that he successfully replaced the CSC Video Controller of the 2300c with the ECSC Video Controller from a 1400. That's on my list for the SuperDuo and I'm fairly sure doing so is a given for making use of additional VRAM in the 2300c.
Dunno for sure though, that was a long time ago.