re atari processors in article r f kp uniwa uwa edu au john gu uwa edu au john west writes ifarqhar laurel ocs mq edu au ian farquhar writes wrong it has a for those who would like to know the was a without irq or nmi and with only address lines giving k memory space yes but still not a for those differences same instruction set of course it had one custom chip not an asic in the sense that word is now understood the tia sometimes known as the although most other manufacturers list that as the cia complex interface adapter tia stands for television interface adapter and it handles sound paddles and the minimal video hardware the possessed didn t know about it being called the thats the cia found in the commodore i don t believe this chip existed when the was around yes the same number but an entirely different device i should have qualified this further by stating that this was the pal version of the tia i am not sure that the ntsc tia would have a different number the tia was mapped into the bottom bytes of page and shadowed in the bottom bytes of page to get an image on the screen you had to wait until the raster line your picture started at load bitmaps for this line into the sprite registers tell them what x positions to take how many duplicates you wanted etc then do it all again for the next line this took all of the processor s time during the visible portion of the display does anyone on the net actually have details of the tia as this is the only device i have not yet discovered details about atari australia when asked claimed that their attempts to get the programmers documentation for the had failed as the us head office had refused to provide it to chip selects the likes to have rom right at the top of memory so the had to use roms with active high chip selects not exactly normal so some cartriges had a in them to convert this to the more usual active low chip select i saw a couple of cheaper devices with pn s and a couple of resistors hooked up as a cheap inverter nasty but workable and cheaper than a inverter if labor costs almost nothing ian
