Atari & Apple II - A 1090XL for Apple hardware

[fibrewire]

Hardware discussion regarding the feasibility of an Atari PBI device that would allow the use of Apple II hardware devices.

 

Also, given the sourcecode for Apple II software is available is it feasible to use existing codebase on Atari's 6502 hardware?

 

What are the major differences between the two platforms that would need to be overcome for such a project?

[Rybags]

Atari is 1.79 and Apple is 1 MHz (or multiples of that) for starters.

 

Secondly, what Apple stuff would we ever want to use?

 

. 80-columns - we already got that, and if needed a cheap(ish) one could be developed.

. more RAM - already got that, and it doesn't need to sit in a great big box.

. printer/comms interfaces - got plenty of them, and again new ones wouldn't be much work to develop.

. sound/speech stuff - already got it, and default Atari sound probably better than most Apple II expansions.

. quicker CPU - nightmare to interface, not worth the trouble, and 7/15 MHz 65816 internal replacements are a way better option for us.

. disk/HDD interfaces - we've got those, and again, they don't need a great big box to house them.

 

Any Apple II card worth having these days probably fetches a good price, it might well be a case of being cheaper for and equivalent that performs the same function to be done in low-volume runs for not much more.

Plus the advantage of our modern-day addons is that they generally become a "standard" and get supported by developers.

Edited April 16, 2011 by Rybags

[fibrewire]

What do loyal Atari 800 supporters do for hard disk access? MG had an interesting idea - using SIO legal calls + Port B from joystick 3 & 4. The cold hard truth set in for me, and I got a 130XE + MIO. I will have forgotten about the Corvus interface by the time it surfaces again, if ever.

 

I guess I'm more interested in 'New Retro' as opposed to just 'New' - FJC Atari GUI, MG MIO, SIO2PC are some good examples.

 

Overcoming limitations that were present during the 'Age of Atari' using original technology and our advanced knowledge is the challenge. I'm not saying that the more modern projects aren't beneficial, but using all this current technology kind of defeats the purpose of using the Atari in the first place. I don't remember wishing for a Cell Broadband Processor upgrade or SIO-2-iSCSI for my Atari 800...

 

To each their own - this Atari ecosystem will carve it's own path. Who am I to decide the fate of the 800s?

[fibrewire]

There are Z80 cards for Apple

 

eBay Auction -- Item Number: 320684661936

[fibrewire]

I guess what I am trying to say is that there are a great many upgrades that involve soldering variable rats nests of wires to the motherboard, desocketing chips, pull this, rip those, cut that... Bob Wooly got it, ICD got it, even Atari adopted cartridges as it's main distribution format. It doesn't get much simpler than that. I feel that these other projects need completeness to avoid crossing the line between Atari and Frankenstein. I can abuse almost any piece of Atari equipment, or ICD equipment, even my gigantic Corvus Systems drive. Our 'experimental - works only in the lab' environment prevents everyone but the upper echelon of Atari enthusiasts from attempting upgrades or conversion.

 

Some kind of expansion system that would accept pluggable cards has got to be the standard. I'm sick of looking at rats nests - give me a card!

[BillC]

There are Z80 cards for Apple

 

eBay Auction -- Item Number: 320684661936

There are the ATR8000 and the Indus GT with RamCharger upgrade for the Atari.

[fibrewire]

It seems our path is similar to The Atari Coldfire Project

 

I think that too much modernization for retro-computing may have an unexpected impact on the very things we support.

 

In the end we will be left with little more than an Atari Flashback - A very useful and future-poof machine, but still only a memory of something that held a special sentimental place in our heart. Hopefully that is what we are trying to achieve - because we are definitely going there.

[+bob1200xl]

The Atari is not designed to have a card buss. This means we need to add wires and cut things just to add the necessary capability for it. So, now you have to hack every system for its maximum configuration before you even get started. You will need 'hooks' into the audio and video, as well as the memory, carts and I/O ports. The 'cure' is sure to be worse than the disease.

 

Look at the progression of the PC. ISA led to PCI, lead to AGP, spawned front-side, back-side, USB and SOB... I can't run any hardware from my original IBM 5150 in my current system.

 

You should have the ability to restore your Atari system to original with minimal or no cutting/soldering/wiring. Other than that, where would you start?

 

Bob

 

 

 

 

I guess what I am trying to say is that there are a great many upgrades that involve soldering variable rats nests of wires to the motherboard, desocketing chips, pull this, rip those, cut that... Bob Wooly got it, ICD got it, even Atari adopted cartridges as it's main distribution format. It doesn't get much simpler than that. I feel that these other projects need completeness to avoid crossing the line between Atari and Frankenstein. I can abuse almost any piece of Atari equipment, or ICD equipment, even my gigantic Corvus Systems drive. Our 'experimental - works only in the lab' environment prevents everyone but the upper echelon of Atari enthusiasts from attempting upgrades or conversion.

 

Some kind of expansion system that would accept pluggable cards has got to be the standard. I'm sick of looking at rats nests - give me a card!

[fibrewire]

You're absolutely right, but how did Atari, ICD, and SWP do it? They were aftermarket, and i've seen projects here including PCBs with socket risers and ribbon cables, needing only a chip puller most of the time, or requiring desoldering a chip and putting a socket in it's place. I know we want to do it on the cheap, but making it look professional is so much more satisifying. At least when making documentation for these various projects, the developer could allow for 'cheap' and 'pretty' methods. And I'm all about documentation.

 

Also, I ENTHUSIASTICALLY appreciate all these wonderous projects, but maybe that could be my job here at AtariAge - cleaning up rats nests

 

As for no card buss, what are the ram module slots for? The S-100 buss is similar, and R-Time 8 runs from cartridge port.

 

Also, IBM was running AWAY FROM the 8-bit as fast as they could - for profit. WE are running away from 8-bit & 74 series DIP as fast as we can because...

[Rybags]

WE are running away from 8-bit & 74 series DIP as fast as we can because...?

 

They're big, and some are becoming more expensive and hard to find.

 

As for the buses on existing machines - the 800 RAM slots don't carry all the needed signals and in any case weren't really designed for other than RAM expansion (excepting Slot 3).

 

PBI and ECI don't carry all the needed signals.

 

One large deficiency in the Atari design is DMA - you just can't have a second DMA source the way the legacy expansion port is done.

 

About the only way around it is to grab the CSYNC signal from GTIA and/or the AN0-AN2 signals from Antic, then have your expansion be able to do it's own DMA based on predictive algorithms where you know that there won't be any contention from Antic.

 

On top of that, we also want the HALT signal from Antic so that RAM expansions can do 130XE-style seperate CPU/Antic banking.

 

This has been gone over before... ideally the PBI would have an extra 5-10 signalling lines which would greatly enhance it's usability.

The thing is that at best that involves pulling chips and replacing with a PCB with pass-thru socket, at worst it involves desoldering, adding socket, plugging in a board.

 

So, realistically we can't do a great deal outside of the realm of existing plug/play expansions without modifying the machine in some way.

[fibrewire]

Also, the 1090XL exists - that sums up the whole argument. We could forget about the Atari 800 all together, and focus on XL & XE computers. I assume that the PBI is the sole reason most move to that platform, so that our machines don't get hacked up.

 

EDIT: Rybags answered my question in the post above this one

[Rybags]

The 800 is in the backwater anyway - has been for years. It's only a "bonus" if an expansion happens to work on it.

 

If an XE compatability upgrade becomes available then a lot of that could change, but lack of PBI would then become the next hurdle.

 

For me, the PBI was just a bonus back in the day.

 

The main drawcards of the XL was the smaller size, bigger RAM and the fact you didn't need to flip a lid to change cartridges.

[fibrewire]

I am gradually learning that I don't know nearly enough to ask complex hardware questions...

 

Is it cheaper to use XILINX chips or to buy direct from Best?

 

http://www.best-electronics-ca.com/custom-i.htm

 

EDIT: I've given up on my A800, at least until Kurt V either says "come buy your Corvus adapter" or "here are the scans of the PCB - you're on your own"