Re: German IIe Question and ROM/JEDEC Link

[heuser.marcus@freenet.de]

Henry (.a.t.) wrote:
>
> Looking at my Euro IIe (220v version) I see it has a larger then normal
> Video ROM and a switch on the bottom front of the case by the keyboard.
> Does the Video ROM have two versions of the Video code in it?

Yes, the ROM is indeed "double sized" (8KB) in comparison to the US one
(4KB).


> Does the switch allow the user to choose which version will be displayed?

Yes to that, too.
AFAIK the first half is the US character set and the second is the
localized (in this case German) set.


> The user also asked about an Enhancement kit for his German IIe.  I was
> unsure about the Video ROM that would be in the computer.  If it is just two
> copies I could easily combine the two he needs then and test them in my Euro
> IIe.

For a working video ROM file ask Bill, he still should have it (he
burned two for me).


> I also assume he'll need the CD and EF ROM's too.

AFAIK the CD and EF ROMs are identical to the US ones - enhanced or
not.


> Now what about the Keyboard ROM?  I see the Keyboard ROM is also a different
> part number then the USA IIe's.

They are indeed different.

> What if they want to convert a USA IIe to a German one?  Does just the Video
> ROM need to be changed or will the Keyboard ROM also need to be updated?

Yup.

>  Will the Keyboard ROM need to be updated as well?

AFAIK there is no enhanced version of the keyboard ROM - whatever the
locality. So any German keyboard ROM should work.

If you want to put a US mainboard into a German Apple (keeping the
German keyboard and power supply) you'll need both localized video and
keyboard ROMs.

You can plug the German keyboard ROM right into the US mainboard (same
size) but for the video ROM you'll need an *adapter* (look into a
certain online store ;o) to which you connect the little switch under
the keyboard to use both caracter sets.

By the way:
The "keyboard switch" actually is a "video switch" - which means it
only serves for deciding which character sets appears on screen. It
does not switch between keyboard layouts but rather switches the
optical representation of the key codes.
This is done IIRC by switching +5V to the A12 line of the video ROM --
the Apple actually doesn't "know" which character set is active so this
is comletely transparent to the DOS or applications.

Important:
If the user is "upgrading" from a PAL mainboard he'll have to use a
longer flat ribbon cable for the keyboard (the keyboard connector on a
PAL mainboard is much closer to the keyboard than on a US mainboard). I
modified a PC floppy cable for this.
If he is upgrading from an "International NTSC" mainboard - a mutant
NTSC board that outputs video at 50 Hz - he should be fine as the board
layout resembles the one used in the US platinum IIe (but different
crystal and IOU chip).

However, you can use a German power supply as its connector works with
a US mainboard.

There are two caveats:

1)
Of course the user of such a modified IIe does need an NTSC capable TV
/ monitor to get color output without additional video hardware.
If the TV is PAL only but accepts "PAL 60" (which is the PAL signal at
60 Hz - the old Amiga monitors do this, for example) he gets a black
and white display. This is resembles the video output of an
"International NTSC" mainboard, but with 60 Hz.
In both cases the user gets an "unsquashed" display which is IMHO an
improvement over a PAL display.

2)
The aux slot isn't in-line with slot 3 anymore. This prevents some
(rare) cards from working.
On the other hand the user has the flexibility of the US board layout.


By the way, using a US mainboard in a German Apple IIe works quite well
and can give a "more authentic Apple feel" - especially for games. If
the user has an NTSC capable display the additional costs aren't an
issue, IMHO.
If his display only works with PAL he of course should go with the
enhancement kit.

bye
Marcus