Re: Apple II ROM

["William Garber" <willy46pa@garberstreet.com>]

"Patricia Shanahan" <pats@acm.org> wrote in message news:qh32h.713$0r.204@newsread1.news.pas.earthlink.net...
: 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.
:
: 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.

Hi Patricia,

If you haven't already, try lifting both ends of each
of the ROMs up about 1/16" and reseat them. This may
clean the pins and socket contacts good enough to make
better contact.

:  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.

Even if there is no contact to one or more data
or address pins, they will still register something,
just not what is being read from or written to them.

: Is there a source for replacement ROM chips?

AFAIK, there are no genuine replacements other than
buying spare boards and keeping the chips out of them.
Adapters to use eproms there are not difficult to make
but I'm not aware of anything under process at the moment.
I haven't been asked to become involved in such a device
as yet. I'd be glad to go ahead and produce some if there
is call for it.

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


Sentimental value should be all that's needed.

William Garber
Email Address - willy46pa@garberstreet.com
Alt. Email - willy46pa@comcast.net
Web address - http://www.garberstreet.com