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RetroChallenge - Project 2008

Replacing Apple //e Logic Board

31. July 2008
Project ID: It works !

It works!...

Yesterday I got the DualROM adapter that Bill Garber from GS-Electronics build for my Apple //e. I replaced the original US Video ROM with the Adapter so I can use the German Keyboard layout and switch between the US and German Keyboard settings. Works great. Also I added the suitable keyboard cable, also from Bill - he was a great help.


The DualROM adapter, on the left you see the plug for the switch which is build in the european Apple //e. One can switch between the US and German Keyboard layout.

Also the longer cable fits and everything is running well. Many thanks to Bill Garber at GS-Electronics!


17. July 2008
Project ID: A Homegrown ROM Adapter...

Some ROM info...

Apple part numbers for enhanced ROM chips from the enhancement kid
for the Apple //e sold by Apple Computer Inc.:

Monitor ROM (CD): 342-0304
Monitor ROM (ED): 342-0303
65C02 Microprocessor: 338-6503
Character Generator ROM: (U.S.): 342-0265
Character Generator ROM: (United Kingdom): 342-073
Character Generator ROM: (French): 342-0274
Character Generator ROM: (German): 342-025
Character Generator ROM: (Italian): 342-0276
Character Generator ROM: (Western Spanish): 342-0307
Character Generator ROM: (Western French): 342-0306


Some more facts from Bill:

Oh yeah, and to use enhanced ROM you will need a 65C02
installed. Also, enhanced IOU and MMU, and System ROM.

You need to put your German Keyboard ROM
into the US board. Otherwise your keys won't match
what you type.

Then when you get my Dual ROM adapter, you can put your
German Video ROM into it, or just use my Eprom.

Bill Garber from GS-Electronics


What a luck, all ROMs on my US board are correctly enhanced.

 


16. July 2008
Project ID: A Homegrown ROM Adapter...

A Homegrown ROM Adapter...

I got some news from Bill Garber who is helping me out with a ROM adapter to use a US/German Keyboard ROM on the enhanced US Board. With the adapter I can use the German Umlauts ÖÜÄ öäü on the US Board. Here are the good news for my Apple //e:

I pulled a bunch of keyboards out, and I have here a very good
cable that is 12" or 305 mm in length. This should do it, and I can
save you a few DMs, bucks. Now I need to burn the eprom, test,
and it's ready to go...

Bill Garber from GS-Electronics
www.garberstreet.com


...

I have both the Un- and the enhanced German ROMs now, so I can
probably burn you one with US and German enhanced ROMs.

Bill Garber


 


15. July 2008
Project ID: Getting some help...

Some more info...

At the google group discussion about this topic there are some more interesting informations about the different Apple ROMs.

The model numbers of the different ROMs

342-0327-A //e (enhanced) Keyboard ROM - German/US, 1982, 2k

The regular one is:

341-0151-A IIe Keyboard ROM German/US, 1982, 2k

Patrick


By the way, 342-0326-A is the number of a French keyboard

Marcus



8. July 2008
Project ID: Getting some help..

Getting some help...

I am getting some help by Bill Garber at www.garberstreet.com and all seems to go into the right direction. I got some more informations about the different ROMs:

> Do you think I get problems because it is an enhanced US Board
> and I only have a "unenhanced" german keyboard ROM? Are all
> needed characters in this ROM or do I need to use also an enhanced
> german keyboard ROM?

The difference is that the enhanced Character ROM has MouseText.
One of those characters is the little Apple with the bite out of it. Do you
ever need those? If not, then the unenhanced character ROM will work.

Bill G.



1. July 2008
Project ID: Do some research

This damn cable...

I have an European (ÜÖÄ keyboard layout) Apple //e with a defect logic board. I bought an Apple //e enhanced board at eBay from U.S.A. to replace the defect board. But at my first look I mentioned that the keyboard port on the US board is on another location than on the European board. The internal (European) cable between the keyboard and this port is to short.

The problem gets bigger... some ROMs need to be changed to have the correct Umlauts (ÜÖÄ) supported by the US board. I started a discussion at google groups about the problem. Here are some of the important informations:

A decent Conrad or similar electronics store should have the needed
connectors and the flat cable. You'll just have to get it together. A
bench vise (Schraubstock in German) is good for getting the connectors
on the cable, just make sure you cut the cable absolutely straight
across, put in some small wooden boards to avoid damaging the plastic of
the connectors with the vise's metal, make sure everything is nice and
straight, and turn really slowly. Don't try to disassemble the
connectors, it's really hard to do without breaking something.

Linards


You need to use a German keyboard ROM with your German
keyboard to get the correct "translation" of keys into key codes.

Thankfully you can just replace the US chip with the German
chip as both have 24 pins.

But now the fun really starts as the US mainboard doesn't
support the little switch that is underneath your keyboard!

This switch selects the font in any text mode on screen
from German (with umlauts) to the US font. You can use
this switch whenever you like - the video hardware reacts
immediately.
This switch connects electrically to the so called "VIDEO
ROM" and selects one of two memory areas (two fonts) in
a non-US mainboard.

On a US mainboard this chip only has one area (one font)
and is smaller than a German (or other non-US country) chip
in capacity and size: It also has 24 pins instead of 28.
This means that you can't simply transfer the chip like the
keyboard ROM!

One solution would be to live with the US video ROM - and
forget the umlauts completely. The text mode should (I'm
not 100% sure) be identical to a German video ROM switched
to the US font.

Another, better solution (especially if you tinker with the
Apple a lot or want to sell it as a unique item in Germany)
would be to get a "video ROM adapter" and plug the German
video ROM into it and the whole thingy into the ROM socket.
Then you connect the switch to the adapter everything should
work like with a German mainboard.

Maybe you can get an inexpensive adapter from Garberstreet
Electronics - ask Bill Garber (you'll find postings of him here)
- which I can assure you do work flawlessly (as long as your
German video ROM is in working condition).

My Apple IIe is built exactly like this (German case, keyboard,
keyboard ROM and video ROM, US mainboard and a video
ROM adapter).

Of course you'll get NTSC video output with 60 Hz but most
modern TV sets in Germany should be able to work with that.
You also get the US picture aspect-ratio which fills the screen
better and displays US software more accurately than the
squashed 50 Hz video of PAL Apples.
The colors usually are way better with the NTSC (because
they are more "authentic") so a US board is worth the trouble,
IMHO.

Be aware that some expansion cards won't work with the
US mainboard (especially European video cards) as the AUX
connector slot is not in line with slot 3 anymore.
The French Le Chat Mauve RGB cards are one example
because they combine 64K RAM with RGB video output.
On the other hand slot 3 becomes a (universal?) slot and
you can use far better cards which were designed for the
US mainboards.

Marcus


I would second that. It works very well. I can't comment on the Bill
Garber adapter as I built my own (for an EPROM, not for a Apple ROM).

The font for the "US half" of the German video ROM is indeed identical
to the original US Apple font by the way. Since I found the original
Apple Umlauts ugly and badly designed I decided to use an EPROM with my
own Umlauts in it.

Not only are the colors and aspect ratio improved, also the beat
(=Schwebung) from the interference of the two quartzes is gone, since
there is only one quartz on the US mainboard.

Linards


 


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