emulatorII-list

Hi,

I'm new to this group and I just bought a damaged EII on ebay.
I managed to fix it by cleaning the head of the 5.25" floppy with q-
tips and ethyl alcohol. Everything works fine now and I can work with 
the EII. What a great machine!
 
But I still have some(maybe) newbie questions.
While opening the EII for cleaning I discovered the "memory option 
board". I wonder what it does. Is it a RAM expansion to 1MB? And if so 
how do I access the second bank?

The main issue I have is that my EII only provides the RS232 interface.
Since I want to connect the EII to a Mac I need to fix that.
Does anyone out there have a PCB layout for modding the EII to accept 
RS422? A scan (top and buttom) of the adapter board would also be great!
It seems to be a very simple circuitry and I think its easy to built.

Thanks in advance!

wintermute

--- In emulatorII-list@yahoogroups.com, "wintermute0815"
<wintermute0815@...> wrote:
>
> While opening the EII for cleaning I discovered the "memory option 
> board". I wonder what it does. Is it a RAM expansion to 1MB? And if so 
> how do I access the second bank?

Accessing the second bank on 1mb E-II+ models is accomplished by
entering double zeros (00).
 
> Does anyone out there have a PCB layout for modding the EII to accept 
> RS422? A scan (top and buttom) of the adapter board would also be great!

Check the group photo and file section technical folders.

Welcome aboard. :)

Hi – and welcome J

 

The RAM expansion is what makes an EII an EII+.

It gives you two banks of 512kb sampling instead of one.

It does NOT allow you to sample a sample that spans the entire 1mb, but it
basically functions as two separate EII’s if you know what I mean.

 

You switch between the two banks by hitting 0 (zero) two times.

 

Kenneth Abildgaard

12bit.com

 

Fra: emulatorII-list@yahoogroups.com
[mailto:emulatorII-list@yahoogroups.com] På vegne af wintermute0815
Sendt: 25. januar 2008 11:21
Til: emulatorII-list@yahoogroups.com
Emne: [emulatorII-list] EII repair and mod

 

Hi,

I'm new to this group and I just bought a damaged EII on ebay.
I managed to fix it by cleaning the head of the 5.25" floppy with q-
tips and ethyl alcohol. Everything works fine now and I can work with 
the EII. What a great machine!

But I still have some(maybe) newbie questions.
While opening the EII for cleaning I discovered the "memory option 
board". I wonder what it does. Is it a RAM expansion to 1MB? And if so 
how do I access the second bank?

The main issue I have is that my EII only provides the RS232 interface.
Since I want to connect the EII to a Mac I need to fix that.
Does anyone out there have a PCB layout for modding the EII to accept 
RS422? A scan (top and buttom) of the adapter board would also be great!
It seems to be a very simple circuitry and I think its easy to built.

Thanks in advance!

wintermute

 



[Non-text portions of this message have been removed]

Hi,

thanks for the infos :)
I found a photo of the mac board in the photos section.
It gives me an impression how to accomplish the mod.
Since I am very lazy :), is there someone who can scan the board from 
top and buttom so I can build the board 1:1 without measuring and 
thinking about the traces anymore. I would also provide the finished 
board layout data to this group when ready.

Welcome!

If you mean the board in the lower right corner, it's the piggypack
RAM of earlier models. As you only have RS-232 I suppose that's what
you have. As memory was expensive in these days, the first models had
64k RAM chips instead of 256k. To have 512kB total, it was neccessry
to have more space for more chips.

Greetings,
Hoschi

--- In emulatorII-list@yahoogroups.com, "wintermute0815"
<wintermute0815@...> wrote:
>
> Hi,
> 
> I'm new to this group and I just bought a damaged EII on ebay.
> I managed to fix it by cleaning the head of the 5.25" floppy with q-
> tips and ethyl alcohol. Everything works fine now and I can work with 
> the EII. What a great machine!
>  
> But I still have some(maybe) newbie questions.
> While opening the EII for cleaning I discovered the "memory option 
> board". I wonder what it does. Is it a RAM expansion to 1MB? And if so 
> how do I access the second bank?
> 
> The main issue I have is that my EII only provides the RS232 interface.
> Since I want to connect the EII to a Mac I need to fix that.
> Does anyone out there have a PCB layout for modding the EII to accept 
> RS422? A scan (top and buttom) of the adapter board would also be great!
> It seems to be a very simple circuitry and I think its easy to built.
> 
> Thanks in advance!
> 
> wintermute
>

Thanks Hoschi,

so I should be able to test this by pulling the option board, right?
The EII should then have a total of 256kB of RAM, is that correct?

I wouldn't do it...
I'm also pretty sure that it's the piggyback ram board.

Such are things you shouldn't do. In fact, if you take out the board,
the selftest would fail, nothing else happens.

--- In emulatorII-list@yahoogroups.com, "wintermute0815"
<wintermute0815@...> wrote:
>
> Thanks Hoschi,
> 
> so I should be able to test this by pulling the option board, right?
> The EII should then have a total of 256kB of RAM, is that correct?
>