Moterola 6510 - Myth

[Felinoid]

Nearly every time I see the 6510 listed as a Moterola chip I think back to the "Commodore NES" listed on eBay.
However there is a fairly good reason for thinking the 6510 was a Moterola product.
Still SOME effort should be filter for myths.
(In this case LOOK INSIDE THE COMPUTERS YOU HAVE)

The history of the 6510:
MOS created the 6500 in direct violation of Moterolas patent on the 6800 buss (same chip buss).
Everyone patented the chip buss they used. (Everyone had a stick up there butts IMAO)
The similar numbers and identical buss made people believe Moterola made the 6500.
Moterola sued MOS.
MOS won the right to make a modified version of the 6500 and paid Moterola damages. 6502 was born.
Commodore used the 6502 in it's programmable calculator along with a math chip by TI. The math chip alone cost $50 so the resulting calc cost $100.
TI desided they wanted to make the same device. They also used the 6502. They charged the same $50 they charged for the math chip alone.
Commodore could no longer produce it's programable calc.

So it was desided Commodore would never again rely on outside chip makers and the took over MOS.

When making the C64 Commodore realised they needed to modify the 6502 slightly to include some memory bank switching so it could have a whole 64k and the 6510 was born.
(Side note the 64 dosen't have a whole 64k but it's only a few bytes short so who cares)

In short the 6510 was made entirely by Commodore and only for the Commodore 64.
The later Commodore 128 would use a radicly altered 6502.. I think they called it the 85??

Apple however had a very good relationship with Rockwell and the Apple II line used 6502 CPUs made by Rockwell.

The 65c02 was made by Western Design Center as a 6502 clone and has nothing to to with Commodore, MOS or Moterola.

Apples choice to use the 65c02 probably had more to do with the lower power consumption than the faster speed.

Side notes:
Rockwell sold a 6502 that could be used at 4mzh this was faster than the fastest offering from Commodore/MOS.

The 65c02 was a 16 bit processor designed as a drop in replacement for the 6502 and 6510 to upgrade the old Apple II, Commodore and Atari 65xx based computers.

Western Design Center (http://www.westerndesigncenter.com/wdc/) is still in business.
The obveously named www.6502.org (http://www.6502.org) is a great resource for those who wish to continue to develup for the 6502 legacy chip.
(It's cheap and effective)

WDC isn't the only company making 6502 clones this project (http://www.free-ip.com/6502/) is making a "free" 6502 core. Nice I guess for those who have chip fabs. Anyone got a spare fab?
This will be of more intrest once replicators hit the market (about 500 years from now)

[carlsson]

We shouldn't forget the MOS/CSG 6509, used in some PET machines and on the data sheet still mentioning "bus compatible with M6800". :)

BTW, I believe the C64 has 64K, but only 62.5K can be used at the same time. By changing memory configurations, you can choose which 62.5K. The C128 chip was 8502, and in the newer C64 revision a 8510 chip was used. There also was a 750x series for use in the TED (C16/+4) machines.

Not sure how drop-inable the 65c02 generally is, even without considering operating systems.

Someone once wrote that for a 6502 programmer, trying the M6809 (which Motorola developed from the 6800?) was like programming on steroids with its extra accumulator, registers and instructions. I have never tried, as I like to stay sober and not do drugs. 8)

[Terry Yager]

Some sources claim that the 6502 was based on the 6800...sort of a not-quite-clone. I dunno how much truth there is to this rumor, as I have not studied the 6502 very much.

--T

[Terry Yager]

My favorite semi-myth about the 6800 chip is the famous but undocumented HCF instruction. I've never been able to verify whether or not this instruction exists, but again, a lot of sources claim that it is real. The HCF (Halt and Catch Fire) instruction supposedly can cause actual physical damage to the data buss due to overheating. What it does is rapidly toggle the entire buss (from 00 to FF, back and forth) until the lines burn out, if left running long enough. Any 6800 programers out there who can shed more light on the subject (preferably from personal experience)?

--T

[carlsson]

Isn't the relationship between 680x and 650x much like that one between 8080 and Z80? IIRC in both cases it was some internal engineer rip-off that lead to chips very similar to the Motorola and Intel ones. Not sure how they could be so much more popular than the originals though - maybe pricing would be a big issue when choosing between two similar CPUs for a computer platform?

[Terry Yager]

I don't know how much similarity there is between the 6502 and the 6800, not having looked into the 6502 very much. (I have been reading up on the 6301 CPU lately, tho...just enough to figure out that I don't want to learn how to program it. It seems way more complicated than the 8080, all those addressing modes). There is, however, some similarity between the 8080 & Z80, but only to a point. The Z80 is the chip that the 8080 should have been. (At least the engineers who designed it thought so, which is why they split off from Intel to form thier own company--Zylog). Even tho it's register & buss-compatable with the 8080, it's archetecture is a lot more complicated, and it's instruction set more complete. Between an 8080 and a Z80, at the same clock speed and running the same program, the Z80 will run rings around the 8080. (It's claimed to be about three times faster). The benchmarks I've been running the last few days seem to bear this out. The Tandy 102 (8085 CPU, 8080-compatable) consistently runs slower than the Cambridge Z88 (Z80 CPU) running the same programs, at a similar clock speed. Although the BBC BASIC in the Z88 may be faster than Micro$loth, I'm not sure if that accounts for all the difference.

--T

[Donni]

BTW, I believe the C64 has 64K, but only 62.5K can be used at the same time. By changing memory configurations, you can choose which 62.5K.

Thats not entirely accurate.
The C64 can access all of it's 64K ram at ones, except for those first two bytes which are the 6510 data direction and I/O register.
This mode was not often used, because none of the I/O devices can be used in this mode.

[carlsson]

I tried to think of a configuration which is useful to run a program in.