when will we get a ula that lets use use the full 64kb of ram that suffers contention and lets us define video modes? 320x200 with 16 and 256 colours as well as 256x192 512x192 640x256 like next and hardware interlace and vdp9990 konix multi system hardware and oh! just everything! well lets face it it wont be long before we just connect a tv to the hdmi output from the byte delight hdmi interface theres a quad core pi zero wonder if it can encode mpeg2 avi video while outputting zx screen$ ?
Probably never. The ULA can only access bank 5 and 7 on a 128K machine which would give you a maximum of 32K to play with. Expanding the RAM so other pages were available to the ULA would be a bigger hardware mod than most people are prepared to do. Even with 32K, a 3.5MHz Z80 isn't really adequate to driving such a big display file.
http://www.e-basteln.de/computing/65f02/65f02/
100mhz 6502!
ula+ has timex hi rez 512x192 but no attributes yes? could ink n paper colours be altered for a word processor?
sam has line interrupt register but only 128 lines per frame ula+ doesnt have line interrupt?
what are the video modes supported by ula+ please? do u understand the floating bus? does this mean zx spectrum cant access 64k of ports?
sam haz hi res mode 3 512x192 but only 2bits per pixel so 4 colours but mode 4 with 4bits per pixel uses a colour lookup table with 16 7bit valus ie 128 colour palette but also the hmpr port has 2 bits so that in mode3 you can switch to 4 x 4 sets of colours this can be done along a scan line according to an article in world of sam every 19 pixels but a dma is 8 times faster ram to port write 2tstates wed nearly get 16 colours per scan line at 512x192