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RAM 320XL


ctirad

  

200 members have voted

  1. 1. I'm interested in:

    • RAM 320XL naked version
      30
    • RAM 320XL full version
      125
    • RAM 320XE
      60
    • RAM 576+
      63

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Hello guys

 

International money transfer from bank account to bank account within the European Union is free for sender and receiver of the money if you choose "share cost". People will need your IBAN (International Bank Account Number) and your banks SWIFT/BIC code. IBAN and SWIFT/BIC can be found via the site of your bank of via special sites. Just enter "IBAN SWIFT/BIC" in Google's search window to find these special sites.

 

sincerely

 

Mathy

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Hello guys

 

International money transfer from bank account to bank account within the European Union is free for sender and receiver of the money if you choose "share cost". People will need your IBAN (International Bank Account Number) and your banks SWIFT/BIC code. IBAN and SWIFT/BIC can be found via the site of your bank of via special sites. Just enter "IBAN SWIFT/BIC" in Google's search window to find these special sites.

Oops, almost forgot. It's only free if you pay in euro's.

 

sincerely

 

Mathy

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  • 2 weeks later...

RAM 320XL available again!

 

Hi, good news for all interested in this card. You can order it again. Note this is exactly the same card as the first batch, It does not fix any issues with a buggy CPUs.

 

The price is the same as before:

25 EUR for the bare/naked card (no enclosure)

30 EUR for the standard one

3 EUR for the optional power pigtail cable needed for unmodified 800XLs

 

The shipping cost (registered package) is 5 EUR over Europe or 6-7 EUR outside Europe.

 

However, because some parts are now slightly more expensive, I had to add a compensation fee for a paypal transfers. Thus, please add 3.5% to the total price.

 

Please make your orders via PM. Thanks!

I've just received it.

As written before, I think this easy to install, small (it is smaller than it seems in photos) and cheap expansion will greatly increase Atari 320KB users base.

High-end software productions can take advantage of this.

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  • 2 weeks later...
Only one question. Is the compy shop mode feature (with little modifications) only in

the new RAM 320XL Plus available ?

 

This feature will be possible in the planned 320XL Plus expansion with some minor mod of the atari mothebroard.

 

There is not and will never be such possibility in the current RAM 320XL expansion.

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Only one question. Is the compy shop mode feature (with little modifications) only in

the new RAM 320XL Plus available ?

 

This feature will be possible in the planned 320XL Plus expansion with some minor mod of the atari mothebroard.

 

There is not and will never be such possibility in the current RAM 320XL expansion.

 

Didn't read the entire thread (yet), but what are the banking bits this board uses?

 

I was just testing a RAMBO 800XL machine and it has 16 16K banks using bits 2,3,5,6 where you can also remap the main 64K into $4000...$7FFF by doing:

 

POKE 54017,128+1 --> Maps main $0000 to $4000

POKE 54017,128+1+4 --> Maps main $4000 to $4000 (useless)

POKE 54017,128+1+8 --> Maps main $8000 to $4000

POKE 54017,128+1+12 --> Maps main $C000 to $4000 (gains that missing 2K lost in I/O space)

 

I guess you didn't rebank main memory if it's 320K.

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Only one question. Is the compy shop mode feature (with little modifications) only in

the new RAM 320XL Plus available ?

 

This feature will be possible in the planned 320XL Plus expansion with some minor mod of the atari mothebroard.

 

There is not and will never be such possibility in the current RAM 320XL expansion.

 

For the unwashed, what does this mean? What is the "compy shop mode?"

 

Muchos gracias.

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Hello wood_jl

 

Compy Shop mode means it uses bits 4 and 5 just like the 130XE but has 256kB of RAM. AFAIK Compy Shop sold a memory upgrade for the 800XL that replaced the 64kb x 1 chips by 256kb x 1 chips. So that would be 256kB RAM (64kB + 192kB), like most other XL upgrades. But most of these 256kB XL style upgrades use bit 5 for bank switching while the Compy Shop upgrade doesn't.

 

sincerely

 

Mathy

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Hello wood_jl

 

Compy Shop mode means it uses bits 4 and 5 just like the 130XE but has 256kB of RAM. AFAIK Compy Shop sold a memory upgrade for the 800XL that replaced the 64kb x 1 chips by 256kb x 1 chips.

 

Not quite correct, the Compy Shop memory expansion board did not replace the 64K of RAM, it only added 256KB to it, blocks 26AE, banks 23,27,2B,2F,63,67,6B,6F,A3,A7,AB,AF,E3,E7,EB,EF and provided separate ANTIC access to XRAM (so it's fully 130XE compatible and even games like "TLC" will run). Expansions that disable the base RAM are far less compatible.

 

Thorsten

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atariksi and Mathy, you are both wrong. The differences between Rambo, Compy Shop and Atari magazine (RAM 320XL) have nothing to do with the amount of the total RAM or the mapping window. It's just about that which and how the control bits of the PortB register are used.

 

A bit of theory. The PortB ($D301) has (of course) 8 bits, PB0-PB7. In the standard 64k XL/XE, only the PB0,PB1 and PB7 are used. PB0 switches on/of ROM, PB1 BASIC and finally PB7 selftest. Other bits are unused. All standard atari RAM expansions use these unused bits (and often also the used ones, see later). Because 6502 cannot address more than 64kB of total memory, one have to use banks. It means, the memory is splitted to the segments (much smaller than a 64kB of course) and these segments are mapped individually somewehere into the addressable 64k space. It was decided to use 16kB segments, which can be mapped to the $4000-$7FFF address space and the PortB bits are used for addressing these banks and trigger the mapping.

 

For a 128kB of total memory it's simple. One have four 16kB banks which are addressed by the PB2 and PB3 bits (2^2 possible combinations) and PB4 is used as a trigger, which maps the bank selected by PB2 and PB3 to the $4000-$7FFF space. This is common for all the expansions mentioned above. The 130XE works exactly like that, but it adds another speciality; an independed trigger for ANTIC chip, provided by PB5. The result is, the ANTIC can see different memory block than CPU in the same space. However, this mode is very rarely used and in addition it does not work correctly on many 130XE machines, thus many expansions do not support this mode at all and use the PB5 for the addressing purposes.

 

For the more memory it's getting a little more complicated, because the addressing of the banks is not linear due to the backward compatibility and also the expansions start to differ. In the RAM 320XL (Atari magazine compatible), bits PB2,PB3,PB4,PB5 and PB6 are used. The bits PB5 and PB6 select one of the four 64kB bank from the 256kB expansion memory and the bits PB2 and PB3 select 16kB segment within this selected bank wich will be then mapped by the bit PB4. And voila, we have 320kB (256 + 64) of total memory is available. The Compy shop, however, supports the separate ANTIC mode, thus the bit PB5 is used for that purpose and bits PB6 and PB7 are used for 64kB bank addressing. As you can read above, the bit PB7 is internally used for enabling the Selftest, so it means that expansion cannot be achieved without modification of the atari and you also cannot access expanded ram and have enabled selftest together. For the RAMBO style expansion it is similar, it just does not support separate antic access. For the more memory, you of course need also more bits for addressing, thus the half MB and MB expansions reuse also bits PB0 and PB1, which means you cannot use basic and ROM (in the 1MB case) and expansion memory at the same time.

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Not quite correct, the Compy Shop memory expansion board did not replace the 64K of RAM, it only added 256KB to it, blocks 26AE, banks 23,27,2B,2F,63,67,6B,6F,A3,A7,AB,AF,E3,E7,EB,EF and provided separate ANTIC access to XRAM (so it's fully 130XE compatible and even games like "TLC" will run).

 

 

Actully "TLC" behaviour looks more as a bug, than the separate Antic access usage. While it works correctly if I don't chnage the car in the menu, it does not work at all on many 130XE machines.

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atariksi and Mathy, you are both wrong. The differences between Rambo, Compy Shop and Atari magazine (RAM 320XL) have nothing to do with the amount of the total RAM or the mapping window. It's just about that which and how the control bits of the PortB register are used.

I guess you meant someone else. I wasn't comparing different methods of implemenation by different parties. I was pointing out that Rambo 256K XL remaps the main memory as well as the extended memory.

 

Or are you saying my question was wrong for asking which bits of PortB your memory expansion uses?

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Hello ctirad

 

It's just about that which and how the control bits of the PortB register are used.

 

Did you read all of what I wrote?

 

However, this mode is very rarely used and in addition it does not work correctly on many 130XE machines, thus many expansions do not support this mode at all and use the PB5 for the addressing purposes.

 

I've never heard about this mode not working correctly on some 130XE's. Separate ANTIC access wasn't implemented a lot, because most people already had 800XL's and didn't see the need to make the computer more complicated then they thought it needed to be. That's why it's not used a lot, not the other way around.

 

.. you also cannot access expanded ram and have enabled selftest together..... For the more memory, you of course need also more bits for addressing, thus the half MB and MB expansions reuse also bits PB0 and PB1, which means you cannot use basic and ROM (in the 1MB case) and expansion memory at the same time.

 

You obviously haven't seen my upgrade yet. My 1MB (+64kB) XEGS only uses $D301, has separate ANTIC and CPU access and has full software control over BASIC, Selftest, OS ROM/RAM and Missile Command. Read more about it on my homepage.

 

sincerely

 

Mathy

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You obviously haven't seen my upgrade yet. My 1MB (+64kB) XEGS only uses $D301, has separate ANTIC and CPU access and has full software control over BASIC, Selftest, OS ROM/RAM and Missile Command. Read more about it on my homepage.

 

I see. You latch the shared signals and thus you don't allow them to change. But is this really a good idea? How do you know if a signal change is related to the RAM adressing or if it is a valid attempt to enable/disable ROM or Basic? In addition most existing 1MB and 0.5MB programs can crash because the will expect "standard" behaviour of the common expansions. I can't tell how serious these issues could be, but I'm afraid it will introduce more problems than it tries to solve.

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I guess you meant someone else. I wasn't comparing different methods of implemenation by different parties. I was pointing out that Rambo 256K XL remaps the main memory as well as the extended memory.

 

Rambo does not remap anything. At least not in the sense related to the "remaping" feature of the RAM 320XL.

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Hello ctirad

 

If software is programmed the correct way, my upgrade works 100%. But if you take shortcuts... But that's how things are with most upgrades. There are many upgrade, that have BASIC ON with one half of extended RAM, and BASIC OFF with the other half. The same goes for OS ROM and Selftest. Funny thing is, each time, half the banks are switched off, but these banks aren't the same for BASIC, OS ROM and Selftest. So you never know what's on or off. If the programmer of the software writes his software as it should be written, all this should not be a problem. But if you take shortcuts, you never know what you are switching on and off and you'll never know what's gonna happen.

 

sincerely

 

Mathy

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  • 2 weeks later...
  • 1 month later...

RAM 320XL available again!

 

Hi, good news for all interested in this card. You can order it again. Note this is exactly the same card as the first batch, It does not fix any issues with a buggy CPUs.

 

The price is the same as before:

25 EUR for the bare/naked card (no enclosure)

30 EUR for the standard one

3 EUR for the optional power pigtail cable needed for unmodified 800XLs

 

The shipping cost (registered package) is 5 EUR over Europe or 6-7 EUR outside Europe.

 

However, because some parts are now slightly more expensive, I had to add a compensation fee for a paypal transfers. Thus, please add 3.5% to the total price.

Please make your orders via PM. Thanks!

How much would is cost to ship to the USA. What would the cost be in dollars.Thank you for your time.

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