Re: Apple II ROM

["Michael J. Mahon" <mjmahon@aol.com>]

Patricia Shanahan wrote:

> Inspired by a History of Computing course I'm auditing, I dug my Apple
> II out and powered it up.
>
> It displays a screen with "Apple ][" at the top, otherwise blank. Reset
> puts it in the monitor, which works correctly. It fails to enter Basic
> or the mini-assembler.

So typing "Ctrl-B, Return" at the monitor prompt does not get you
to the BASIC prompt?

The original (non-Applesoft) Apple ][ did not initialize BASIC
automatically.  It had to be cold started from the keyboard.

> I've used the monitor to display ROM contents. The Monitor ROM, F800 and
> up, matches pieces of code in the Reference Manual. The remaining ROMs
> contain what looks like junk, and do not match Reference Manual listings.
>
>  From the functioning monitor, and good readouts from monitor ROM, I
> conclude that the ROM address and data paths work. That makes me think
> that the junk data from the other ROMs is due to failure of the ROM
> chips themselves.

Although this is possible, it is not a likely failure.

> Is there a source for replacement ROM chips?

The original set of 4 ROMs, Monitor and Integer BASIC, are a
little hard to find.  Best bet for the 3 Integer BASIC ROMs is
a "firmware card" with the Integer ROMs installed--they show up
on eBay from time to time.

> Although the computer has no practical use, it has very great
> sentimental value as my first personal computer.

I hear you loud and clear, Patricia.  ;-)

-michael

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