"Sally" versions...

[dimfil]

Are there any differences between different versions of 6502C that I found online?

I mean, I found C014806C-29 or 14806-35 for example... Is there any difference concerning installing on a 600xl or a 800xl computer?

Most probably the CPU is a problem on one 600xl I have and I would like to know if I should choose one or another chip to buy...

Edited February 15, 2019 by dimfil

[xrbrevin]

i know they are interchangeable - ive diagnosed a 400, 600xl, 800xl, 65xe, 130xe by chip-swapping and they dont seem fussed by the different types.

Could they just be different manufacturers of the same spec item?

I think i read somewhere that very early 400/800 models used a 6502A until some time thereafter the 6502C became standard

[jowi]

I've read that later versions had some bugfixes as well.

[+Nezgar]

400/800 use a standard 6502C, and can be replaced with common equivalents online. These cannot be used in the XL/XE.

 

All the XL/XE's use an Atari customized '65C02' variant that will not work in the 400/800.

[+DrVenkman]

400/800 use a standard 6502C, and can be replaced with common equivalents online. These cannot be used in the XL/XE.

 

All the XL/XE's use an Atari customized '65C02' variant that will not work in the 400/800.

I believe that’s not quite accurate. Early 400/800 machines use standard 6502B chips (bog standard MOS 6502 design that passed bin testing at 2Mhz). Later 400/800 units used the 6502C SALLY Atari modified design that adds the HALT line to the chip. The 65C02 is a CMOS chip, as I recall, and is NOT the same as the Atari 6502C.

 

Confusing, I know.

Edited February 15, 2019 by DrVenkman

[+Nezgar]

Ok I stand corrected! I didn't realize there was a variant of the 400/800 boards that could use Sally. TIL. Thanks

[+MrFish]

Early 400/800 machines use standard 6502B chips (bog standard MOS 6502 design that passed bin testing at 2Mhz).

 

I believe you're wrong there about the "6502B @ 2Mhz". Follow this trail: Reply: "2 MHz"

Edited February 15, 2019 by MrFish

[+DrVenkman]

 

I believe you're wrong there about the "6502B @ 2Mhz". Follow this trail: Reply: "2 MHz"

 

Ah, you appear to be correct. The thread you linked to linked in turn to another from around 2010 (which first seemed to confirm what had said, probably picked up and passed around from an Atari computer article back in the day …), and then to 6502.org, which in turn led me to the MOS datasheet for the 6500 family.

 

EDIT: And also of interest, the preliminary May 1976 version of the same. Also interesting that this particular document does not mention the 6507 variant, the one Atari used by the tens of millions in VCS/2600 consoles, disk drives, etc. I don't recall the exact timing (Joe DeCuir or Curt Vendel probably would though) but Atari had to have been playing around with VCS concepts by not long after that up in Grass Valley if they'd have them ready to sell by September 1977. So I wonder why they're not in this datasheet?

Edited February 15, 2019 by DrVenkman

[+MrFish]

Ah, you appear to be correct. The thread you linked to linked in turn to another from around 2010 (which first seemed to confirm what had said, probably picked up and passed around from an Atari computer article back in the day …), and then to 6502.org, which in turn led me to the MOS datasheet for the 6500 family.

 

I was going to point you directly to the datasheet, but I think it's good to link these 3 conversations together here on AA; it helps answer a lot of questions that might come up.

Edited February 15, 2019 by MrFish

[BillC]

400/800 use a standard 6502C, and can be replaced with common equivalents online. These cannot be used in the XL/XE.

 

All the XL/XE's use an Atari customized '65C02' variant that will not work in the 400/800.

The 6502C is SALLY, the 400/800 originally used the standard 6502B. A different 400/800 CPU board was released later that used the 6502C.

 

The 65C02 is a CMOS version of the 6502, not SALLY.

 

https://en.wikipedia.org/wiki/MOS_Technology_6502

 

 

EDIT: didn't read the entire thread before replying

Edited February 16, 2019 by BillC

[Kyle22]

There a few extra logic chips on the board that supports the regular 65xxx chips. The Sally board has less chips. I have a 65C802 in my 800 that runs the BBS. It runs 16 bit code, but doesn't support addressing above $FFFF.

 

Of course, it's the original board that is compatible with the regular 6502, 65C02, 65C802.

 

Our Sweet-16 used a GAL (soldered upside down [on the bottom of the board]) was not an attempt at copy protection. It was because of a mistake, but we made it work! It was an 816, but no extra RAM.

 

If I had only known then what I know now... (also factor into the equation that RAM wasn't as small or cheap back in the 90's).

 

The best new product I can think of is a similar device that allows an 816 to fit in a Sally socket (actually 2 versions needed, original & Sally) and has Lots of RAM (16M or so). This must fit in an original 800 if it is an adapter like the Sweet-16, or maybe a whole new card will be required (for the 400/800).

 

It won't be Rapidus, but it will have RAM. This requirement is different from Antonia. This must work with Incognito and U1M.

 

That is what I would like to see. I believe these will sell well. I know I could sure use one.

 

Edit: the RAM onboard must be addresses at $10000. The next number above $FFFF, and there must be logic to keep access to $1xxxx (and above) from touching the original hardware. These addresses must be kept off the bus to avoid disturbing the Dxxx and other hardware.

Edited February 16, 2019 by Kyle22