[R-390] Progress?

[John Saeger]

Ah, we are talking about different things.  I was talking about the Atari
2600 game console, which to me is their first *computer*.  In that case,
there is no ROM in the console.  It has 128 bytes of memory total.  All of
the ROM is in the cart.  But it does have a 6502 instruction set.

And no, I'm *not* sorry.  ;-)  I think it's interesting to be in a far
corner of the cyberverse and find somebody with a similar interest.
Actually, I think they were still making R-390A's when the 2600 came out.
That's kinda interesting...  And to this day, people writing games for the
2600 are unsuccessfully trying to find ways to copy protect them.

BTW, if you like you can check out my 2600 emulator here:

http://www.whimsey.com/z26/

But you're on your own finding the bootleg ROM images which are illegal to
possess.  ;-)

John


> Yes, a Barry wrote the above snippet.
>
> The cartridge is ROM only. Different from the ROM and RAM in the computer.
I
> think the carts went up to 8k and then bank switched for anything more.
That
> is why the super cart games flickered. The flicker was the switching of
> ROMs. I was never into carts much except to get the data out and make boot
> sectors so that I could run the games from floppies.
>
> No, those computers eventually had 128K of RAM, but with the 6502 chip it
> could only address 64K at any one time. This is kilobytes, not bytes.The
> other 64K was bank switched. This was an 8 bit CPU chip, so the math only
> goes to 64 something thousand (64K). You had 4K reserved for BASIC, which
> you could kick out if you knew how so that you really had 52K of RAM to
use.
> I modified one 8 bit computer to have 256K and another to have 576K. You
> were pretty much on your own back then when it came to modifying hardware.
I
> had to patch my DOS for the extra memory banks in 8K boundaries. I had no
> idea if my patches would work but they did the first try. I was terrible
in
> hex math.
>
> Funny, but I found 6502 programming easy. I learned ML. Trying to learn
> Motorola 68000 programming proved too tough. I think it had 8 data
registers
> and 7 address registers. The last one was for the stack...I think. Plus,
> breaking data into words and longwords was tough enough, but mixing bytes
> and words did me in. You mean to tell me that you didn't like rotating
bits
> right or left?  My personal favorite was the WD fdc. Head step settle
times,
> etc.
>
> Learning copy protection schemes pretty easy on the Ataris. The ST was
easy
> to learn. It's kind of a funny reminescience to see the music CD copy
> protection being beaten so easily. It reminds me of the days of fuzzy
> sectors, elliptical tracks, data under the index hole sectors, minus
tracks,
> branch on equals,  etc.  I never thought the copy protection for CDs would
> last long. Same old story, different centuries. Folks will never learn.
>
> I bet you are sorry you asked now!!!
>
>
> one of the Barrys and I ain't saying which one
>
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