More on the RCA Studio II

I know it's bad form to reply to your own posts, but here it is. --- Ethan Dicks <ethan_dicks(a)yahoo.com> wrote: I just opened it up... some previous owner has scrawled lots of notes in pencil about what does what. Address lines labelled, component symbols (on the solder side), memory address ranges, controller key numbers... Lots of good info. The board itself resembles the Quest Elf in its layout style - lots of room and waves of curved, parallel traces. Outside of the RF cage are the CDP1802CE, an RCA TA10171V1 (the video chip), four 1822 256x4 SRAMs ($0800 - $09FF), four 1831 ROMs (512 bytes each) [$0000 - $07FF] and the glue logic: one 4042, one 4001 and one 4515 (which I think is the latch for the game controllers). The timing and power section is a 555 and a 7805, pretty pedestrian stuff. The date codes suggest a timeframe of 1Q77. The ROM carts use a .154"-spacing single-sided 22-pin connector, so RatShack has boards I can use to make my own. It's just stunning to open this up and have this kind of documentation in place. The 1802 is a simple beast. This guy obviously did what I was going to do - start with the known CPU signals and work out. What I _wasn't_ planning on doing was marking up the original. I'm glad he did. One odd thing about this design - DC power come into the RF switchbox that clamps to the TV. There is a single RCA cable that connects the switchbox and the game unit. It appears as if power goes one way down the cable and video data goes the other way. Strange. -ethan ===== Infinet has been sold. The domain is going away in February. Please send all replies to erd(a)iname.com _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com