Is it true the prototype 2600/vcs used a 6502 and not a 6507

[carmel_andrews]

According to the text in the follwing link, they claim the proto 2600 used a 6502...interesting, so why did they switch over to the 6507 (or were warner's like tramiel, i.e cheap and cheerfull)

 

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http://www.cpushack.com/tag/6502/)

 

 

And the text

 

Wired has an interesting article about several prototypes of rather historical devices. Of much interest are the Apple 1, and the Atari 2600 although the doorbell powered Moog is pretty classy as well.

 

Take a look at the Atari 2600 prototype and notice that they used a MOS 6502 in it. The final version used the lower cost (and smaller) MOS (or Synertek) 6507.

 

Atari 2600 Motherboard - 6507 CPU

 

When designing a product, it often is easier to use the standard full featured version of an IC for development work, and then as you refine the design, trim down to the least, and smallest components you can.

We also learn how Foxconn got its idea of low wages. Steve Jobs himself paid his sister a mere $1/board to assemble the Apple 1.

Its interesting to see how prototypes can be so vastly different from the finished product. A fact that design engineers know all to well. “I have to put all of THAT into what?”

 

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Were there any advantages of Atari going with the 6507 (apart from cost) then the 6502...Or was it Atari's intention all along to make an updated version of the 2600 using the 6502 (a'la the Atari 8bit)

[Syntaxerror999]

I think cost was the main drive. Bushnels idea was that a home console had to be as cost effective as posible. The TIA itself was costly to design, but once it was completed was extremely cheap to manufacture.

[atari181]

At that time spending the extra $ on the 6502 really wouldn't make sense . Especially as it was only made to play the first few Atari titles that were produced. It wasnt meant to be the juggernaut it became

[kskunk]

The "number of pins" is a substantial part of a chip's cost. With a tiny, high yielding, chip like the 6502, the number of pins can be the most expensive part of making the chip! Every pin you add increases the risk the part will fail, requiring costly rework or more likely just being trashed. This was especially true in 1977, when wire bonding technology was still primitive.

 

The 6502 was famous for costing $25, which is like $90 in modern money. I'm sure Atari got a better deal than that, but let's assume they got a 30% price cut for cutting off 30% of the pins in the 6507.

 

That's no small savings. Over the first couple of years, that kind of savings would pay the salaries of dozens of engineers.

 

- KS

[SoundGammon]

Here's a pic of the 2600 prototype, thanks to Curt's museum!

[Wickeycolumbus]

Were there any advantages of Atari going with the 6507 (apart from cost) then the 6502...Or was it Atari's intention all along to make an updated version of the 2600 using the 6502 (a'la the Atari 8bit)

 

I think it was all in the cost. Having the A8 and 5200 use 6502 variants didn't stop them from sticking a 6502 in the 7800.

 

Here's an older post where Joe Deciur commented on things he wished were done differently on the 2600:

 

http://www.atariage....ost__p__1684074

 

Excerpt:

 

Examples of 'wish we had done it differently':

- use 40 pin 6502 (cost 50 cents more, all in packaging)

- connect IRQ pin to 6532, so that we could run two threads: display, and game processing

- use 30 pin cartridge connector (cost 50 cents) to add top three address lines, R/W, clock, decode back

- hposition comparators (see above) instead of hmove register/counters

- if we could have afforded the chip area, have 40 bits of playfield instead of 20, used in one of three ways:

1) 40 bits across (cover the whole line with 4 clocks/bit)

2) 80 bits across, reflected (40 then 40)

3) 80 bits across, repeated (40 then 40)