AUX RAM howto

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tkh
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Joined: Jun 26 2013
Posts: 34

Let's say that I have 256kb of RAM on my AUX card, and also 256kb from my transwarp card.

The question is: How do I use them?

ProDOS user disk only gives out 128kb (which is 64kb + 64 kb, in contrast to 64kb + 512kb of mine)
/RAM partition only shows 64kb of space available.

So how do I make them usable?
Thank you

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Joined: Dec 20 2003
Posts: 359
Re: AUX RAM howto

First, you can’t use the RAM on the Transwarp card. The card itself is already using it. The RAM on the Transwarp is accessed at 3.5mhz so on startup the Transwarp copies the ROM to it’s RAM. It also uses it’s own RAM instead of the motherboard RAM and the first 64k of the Aux card. You can actually run a IIe or II+ without any RAM on the motherboard if you have a Transwarp installed. Don’t know if that applies to the Aux slot card as I’ve never tried it.

It’d be good to know the brand of your aux slot card. AE cards were the most common 3rd party card so Appleworks and most RAMdisk utilities worked with them. There were other manufacturers that needed their own utilities though.

tkh
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Joined: Jun 26 2013
Posts: 34
Re: AUX RAM howto

Thank you for your reply!

I see... Too bad for the Transwarp, huh...

My AUX card is Legend E card, the one with color video output pigtail

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Joined: Dec 20 2003
Posts: 359
Re: AUX RAM howto

You can find a copy of the manual at http://apple2online.com. Legend E cards aren’t very common. Unless by luck someone here has one, reading the manual may give you the most information. I don’t have an E card, I do have Legend RAMcard for the regular slots. Mine came with RAMdisk software and not much else. I really haven’t used it in the last 25 years as right after I picked up a Ramworks and a Ramfactor. They were easier to use and more versatile cards.

tkh
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Joined: Jun 26 2013
Posts: 34
Re: AUX RAM howto

So I went through the technical detail on Legend E'Card manual, and it was mentioning the bank switching concept.

It's telling me how it works on machine language level. It includes reference to a memory address that seems to be the switch.
The address $C071 is the one.

In conclusion (as far as I grasp), one way to use this is by poking around to change the value of this switch.

The other way mentioned in the manual is by using AppleWorks, which I refrain to.

Thanks again!

tkh
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Joined: Jun 26 2013
Posts: 34
Re: AUX RAM howto

I tried looking at the soft switch and it didn't work out.
The value didn't change when I tried putting the value that I want (tried using poke from basic and also using monitor).

When I tried looking at the value of the 'supposed to be' area of soft switches, the values are all $FF.

Do you have an idea of what I am missing here?

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Joined: Jun 15 2014
Posts: 305
Re: AUX RAM howto

I've never seen the docs for your card but I bet the bank switching register is write only, e.g. cannot be read out. At least that is how ramworks C073h register is working. Are you sure your auxiliary ram card's full capacity is not recognized by locksmith 6.0 fast backup utility?

tkh
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Joined: Jun 26 2013
Posts: 34
Re: AUX RAM howto

georgel wrote:

I've never seen the docs for your card but I bet the bank switching register is write only, e.g. cannot be read out. At least that is how ramworks C073h register is working. Are you sure your auxiliary ram card's full capacity is not recognized by locksmith 6.0 fast backup utility?

At least I know that it works similar. I don't see why they would be too different, anyway--provided that there are standards to this.
I will start to figure out a way on how to really see if it works.

Locksmith fast backup utility? I have not check that out yet...

tkh
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Joined: Jun 26 2013
Posts: 34
Re: AUX RAM howto

Oh, wait!
So looking through the manual of Transwarp, I came into conclusion that the ROM and IO address of Transwarp replaces the ones of aux card.
It was referring to the address of $C074 as a soft switch that changes the clock speed.
I also have the knowledge that the entire $C0 page is taken up for auxiliary card operation, while each page from $C1 to $C7 is for each card on expansion port (except for $C3/slot 3)
With this I see that in this case, where the soft switch of Transwarp clock speed resides on the supposed-to-be location for my Legend E'Card, the whole page is being used by Transwarp instead.
It is not a safe assumption, though... This is where I need people to correct me.

Now the question is: Could it be that the soft switch for the memory bank resides in $C073 instead of $C071?

I am going to check if this really works.

speedyG's picture
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Joined: Nov 16 2011
Posts: 2413
Re: AUX RAM howto

Hello tkh,
if expansioncards are residing in different slots the softswitches are related to the used Slots:
The adressing ranges are also dependent to the fact
if the Dev-Select or the IO Strobe line from the slot is used....
so in one case the Adressing range
is at Cn00 and at the other C0n0 - where n = ( Slotno. + 8 ) or in direct converted ranges:
DEV SEL is located from C08x to C0Fx - where x is any hex number from 0 to F
..................................and at the IO Strobe line the range is from C800 to CFFF

or if you like it as Table:

SLOT.........DEV SEL..............IO Strobe
Slot 0.......C080 - C08F.......C800 - C8FF
Slot 1.......C090 - C09F.......C900 - C9FF
Slot 2.......C0A0 - C0AF.......CA00 - CAFF
Slot 3.......C0B0 - C0BF.......CB00 - CBFF
Slot 4.......C0C0 - C0CF.......CC00 - CCFF
Slot 5.......C0D0 - C0DF.......CD00 - CDFF
Slot 6.......C0E0 - C0EF.......CE00 - CEFF
Slot 7.......C0F0 - C0FF.......CF00 - CFFF

Because the range of adresses determined by the Device Select Line contains 16 valid adresses
(C0X0 to C0XF ( 0 to F ) this area is used in general for softswitches
while in general ( if the card contains RAM, ROM or EPROM )
the range of the IO Strobe which contains 2048 valid adresses
(CX00 to CXFF ( 00 to FF )is used for adressing the content of that memory devices ( RAM,ROM or Eprom )on the expansioncards.
This technique is used in nearly all expansion cards to avoid conflicts of interaction between cards in different slots.
You should review the manuals of both cards for correct interpretation about this point....
and probably read chapter 7 of the book
"Understanding the Apple II" by Jim Sathers:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Books/Jim%20Sather%20-%20Understanding%20the%20Apple%20II.pdf

speedyG

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