minor changes while fiddling; added definition of SRAM2
For lulz, added a (commented out) dma-from-SRAM2 option, and gltching still occurs; the problem is twofols .. hitting SRAM1 during DMA, or hitting GPIO during DMA, will glitch. Use FSMC memory controller or USART/I2C to talk to other chips, as they are on other buses.. and feed them into SRAM2 fia DMA1, say. FSMC to mount the Z80 RAM may be most awesome...
VGA fiddling more .. slightly optimize non-DMA approach, so its pretty workable; less glitchign when GPIOs going on, so maybe workable without intermediary; still lots of avenues to pursue that may alleviate it anyway..