Info needed on 64K EEPROM for BX-24

Started by lgharriman March 5, 2005

I would like to change the 32K EEPROM on the BX-24 to a 64K EEPROM.
Does anybody know which chip I should use. Also does anybody know of
a wiring diagram to hook up the 64K EEPROM externally.
Thanks in advance




--- In , "lgharriman" <lharriman@t...> wrote:
> I would like to change the 32K EEPROM on the BX-24 to a 64K EEPROM.
> Does anybody know which chip I should use. Also does anybody know
> of a wiring diagram to hook up the 64K EEPROM externally.

I haven't seen any information from NetMedia to suggest that this is
supported in any way. However, if you want to try something (while
voiding any warranty and risking damage to your BX-24) there is
information in the BX-24 schematic that will guide you. To be
successful, you'll have to somehow disable the 32K EEPROM that is on
the BX-24 board. This could be done by lifting pin 1 of the EEPROM
and tying it high.

The next step would be to connect the new EEPROM to the BX-24. The 7
holes running down the left side of the BX-24 board (from near pin 24
to near pin 1) contain all of the signals that are needed to connect
to the EEPROM.

Electrically, that will do the job. However, it is not clear whether
the code inside the BX-24 would ever send an address to the EEPROM
that exceeds the expected 32K. Moreover, it is not clear that the
compiler will generate code beyond 32K when it is configured for the
BX-24.

Don



Re: Info needed on 64K EEPROM for BX-24
Re: Info needed on 64K EEPROM for BX-24
There is a photo of a 64K EEPROM in the group photos; I don't know who
posted it. The following link surely won't work, so just take a look in
the group photos.

http://photos.groups.yahoo.com/group/basicx/vwp?.dir=/&.src=gr&.dnm=bx24
+%2b+64k+eeprom.jpg&.view=t&.done=http%3a//photos.groups.yahoo.com/group
/basicx/lst%3f%26.dir=/%26.src=gr%26.view=t
Tom
Tom Becker
--... ...--
www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700



Re: Info needed on 64K EEPROM for BX-24
Here is the post about the 64k EEPROM mount:

http://groups.yahoo.com/group/basicx/message/14273 Tom
Tom Becker
--... ...--
www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700


I use BX-35 to avoid this exact problem of squirrelly mounting. The
advantages are:
- cheaper than BX-24 even with support chips
- ability to swap or modify the support chips at will e.g. use a MAX232
for TX/RX, use bigger EEPROM etc
- full access to all of the chip functions (some just aren't available
on the BX-24)

The downside (not much for me) is that it takes more room and as it not
as integrated as the BX-24.

BTW I have one unused BX-35 for sale. Optionally I can provide the
EEPROM, crystal, and capacitors as well. Make an offer.

Mike

> Here is the post about the 64k EEPROM mount:
>
> http://groups.yahoo.com/group/basicx/message/14273 > Tom >
> Tom Becker
> --... ...--
> www.RighTime.com
> The RighTime Clock Company, Inc., Cape Coral, Florida USA
> +1239 540 5700
>