SV: [basicstamps] Extra memory
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Posts: 46,084
Greetings!
There's a slight problem with those...
They're all Parallell ported, so need a lot of pins to access.
There are ways around that, but not easily.
One way would be to use shift registers to clock the address and DATA info
to the chip, but then you're much better off using ordinary Serial EPROM's.
http://home.c2i.net/trygveh/english/gadgetman/pocket/psion/org1pak.html
This is how it was done on a Psion Organiser from 1984.
The same technique should be applicable today. Just add a shift register for
the DATa bus.
(Probably needs some work to match it to the ERASE functionality)
Please note that some FLASH chips need a 12V pulse when programming... (And
even older EPROM's need a 20V pulse)
:-)
Trygve
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Fra: iphillipsca [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=iky_0_V964BzRmMI2RqR76M7YMXFqxswirYybTMnlOXusnum3SS0WbF6EG6SwZSXZHGXnJmQfcvYfsf5HQaC]iphillips@s...[/url
Sendt: 9. august 2002 14:20
Til: basicstamps@yahoogroups.com
Emne: [noparse][[/noparse]basicstamps] Extra memory
Anyone ever use a flash bios eeprom form a computer as extra memory?
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There's a slight problem with those...
They're all Parallell ported, so need a lot of pins to access.
There are ways around that, but not easily.
One way would be to use shift registers to clock the address and DATA info
to the chip, but then you're much better off using ordinary Serial EPROM's.
http://home.c2i.net/trygveh/english/gadgetman/pocket/psion/org1pak.html
This is how it was done on a Psion Organiser from 1984.
The same technique should be applicable today. Just add a shift register for
the DATa bus.
(Probably needs some work to match it to the ERASE functionality)
Please note that some FLASH chips need a 12V pulse when programming... (And
even older EPROM's need a 20V pulse)
:-)
Trygve
Opprinnelig melding
Fra: iphillipsca [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=iky_0_V964BzRmMI2RqR76M7YMXFqxswirYybTMnlOXusnum3SS0WbF6EG6SwZSXZHGXnJmQfcvYfsf5HQaC]iphillips@s...[/url
Sendt: 9. august 2002 14:20
Til: basicstamps@yahoogroups.com
Emne: [noparse][[/noparse]basicstamps] Extra memory
Anyone ever use a flash bios eeprom form a computer as extra memory?
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/