Atari 800 CPU board schematics with SALLY?

[candle]

Hi,

I'm looking for schematics with Sally CPU in place of standard 6502 - i could find the other one in numerous sources, but the one with sally - not really

Anyone?

 

[DrVenkman]

SAM’S COMPUTER FACTS for the 800 (available on Atarimania) has schematics for both CPU boards. 

[Gunstar]

Is there an easy way to tell the difference between the boards without schematics? Any obvious distinguishing differences like an IC in a different location or facing the opposite way like PAL vs. NTSC?

Edited June 28, 2021 by Gunstar

[DrVenkman]

7 minutes ago, Gunstar said:

Is there an easy way to tell the difference between the boards without schematics? Any obvious distinguishing differences like an IC in a different location or facing the opposite way like PAL vs. NTSC?

Yeah, this came up during the big Incognito thread a couple years ago. The SALLY version is rearranged compared to the original stock 6502B version. The SAM’S doc I mentioned above has photos of each board as well as schematics. I have photos myself somewhere but not on this tablet and I’m supposed to be working so … 

[TGB1718]

Here they are from SAM's

 

[Faicuai]

7 hours ago, candle said:

Hi,

I'm looking for schematics with Sally CPU in place of standard 6502 - i could find the other one in numerous sources, but the one with sally - not really

Anyone?

 

In the event you may have not tried so, and/or if you cannot find what you need in writing / drawings, these would be your best shots with Qs related to that board:

 

@ClausB

@tf_hh

 

As for me (and other through-and-through, 800 daily-drivers users present here), we have plenty of HW, parts, boards, test-beds and basic instrumentation. If there is anything you need to back-test or triple-check on our end, don't hesitate.

[Gunstar]

Thanks @DrVenkman and @TGB1718. I dug out my spare NTSC 800 mobo and boards and the NTSC CPU board I replaced with a PAL board in my every day 800. I have one of each of the NTSC boards and the PAL board is like the original (top pic).

 

 

Edited June 28, 2021 by Gunstar

[candle]

thanks for your info,

I wonder what was the motivation behind choice of signals buffered with 74ls244 chip used on this board

for A0-A3 one could speculate that they have wider fanout (are connected to more devices) - but really - that would be two more, and in fact, just A0-A1 goes to two chips more, and A2-A3 just to Pokey

 

it seems like someone wanted to do this right, but then came accountant

 

[Gunstar]

1 hour ago, candle said:

thanks for your info,

I wonder what was the motivation behind choice of signals buffered with 74ls244 chip used on this board

for A0-A3 one could speculate that they have wider fanout (are connected to more devices) - but really - that would be two more, and in fact, just A0-A1 goes to two chips more, and A2-A3 just to Pokey

 

it seems like someone wanted to do this right, but then came accountant

 

I know English isn't your first language, but your English writing is better than most of my country redneck neighbor's, those who can write. But I'm a bit curious about your last sentence as it could be read two different ways:

 

"it seems like someone wanted to do this right, but then became an accountant." or "it seems like someone wanted to do this right, but then came the accountant."

I'm leaning toward your meaning the second way, but just want to  be sure...

[candle]

urgh,

 

what I ment, was that engineer(s) who designed this board wanted it to be designed properly, as all backplane based computers would be, but at the end of the day, were informed, that their design is too expensive, and they have to redesign it so it would be cheaper, and in the result we have what we have with some kind of compromise - thus the accountant

 

in general, in polish language there is no such thing like "a" or "the" (we have flexion) so i have only faint idea on how to use them, and where to use them

sorry

 

[DrVenkman]

26 minutes ago, candle said:

urgh,

 

what I ment, was that engineer(s) who designed this board wanted it to be designed properly, as all backplane based computers would be, but at the end of the day, were informed, that their design is too expensive, and they have to redesign it so it would be cheaper, and in the result we have what we have with some kind of compromise - thus the accountant

 

in general, in polish language there is no such thing like "a" or "the" (we have flexion) so i have only faint idea on how to use them, and where to use them

sorry

 

I understood your meaning, I think, but I understand Gunstar’s confusion. No need to feel bad - your English is light years better than the only other language I’e studied intensively (French, 30+ years ago). 

 

But I think you’re right. The 48K 800 has what? SEVEN different PCBs? Plus a nice keyboard, a large, complicated set of case plastics and that massive cast RF shield. That’s an expensive machine. Look at the 1200XL designed in 1992, just 3-4 years later and they’ve simplified it down to a single board, and then the 800XL which is an even smaller, more efficient design. 

 

The 800 must have been been a LOT more complicated to build in terms everything from parts to material to assembly labor to transportation and distribution costs compared to later models.

 

[candle]

Atari 800 is built as it is because of FCC regulations of that era - one year later, and we had a diffrent story (VIC, C64) where piece of metalised cardboard was good enough

 

[Faicuai]

1 hour ago, candle said:

Atari 800 is built as it is because of FCC regulations of that era

That of course, and also to go after what Atari considered its (main) competitor to beat in the home market (Apple).

 

The 800 also has that open "spirit" but with more purpose-specific slots (being slot-3 an interesting exception) and with user-simplicity in mind for expanding RAM (which was POWER HUNGRY and EXPENSIVE at both Apple and 800's time).

 

What came after such competitive-cycle was a never-ending, cost-cutting new cycle to "catch-up".... with Commodore C64´s, thus the ensuing products (and their design). In other words, XL and XE lines had heavy-handed accountants all over them.

 

 

 

 

[Rybags]

Related query - has anyone decapped a Sally series 6502 chip or otherwise done a deep down comparison to a normal 6502?

[Mazzspeed]

On 6/29/2021 at 11:58 PM, Faicuai said:

What came after such competitive-cycle was a never-ending, cost-cutting new cycle to "catch-up".... with Commodore C64´s, thus the ensuing products (and their design). In other words, XL and XE lines had heavy-handed accountants all over them.

Translation: Computing had to become remotely affordable if mass consumer adoption was to become a reality. Yes, the 800 was an overbuilt tank of a machine - But the reality is that with the latter relaxing of FCC regulations, upcoming machines didn't need to be built like a wheel chock. Even the latter IIc followed suit regarding expansion slots.

 

Edited July 6, 2021 by Mazzspeed