🚀 go-pugleaf

Dallas is a good company to work with.  They have a credit card sales
dept that sells small quantities shipped overnight.  There number
is 1-800-336-6933.

So far I have only worked with the DS2250T-64-16.  This is a small
40pin simm chip.  It has an 8051 compatable microprocessor, a clock
and 64k of non volitile ram.  The all the memory and clock run off
a flat pack lithium cell for 10 years.  If you raise PSEN* to 5v
and bring RST to ground it autobauds on the serial input.  There
is a system loader to send intel hex files and dump memory and such.
Once loaded the program is write protected.  It is really great
to do development without hasseling with eproms, also since the external
bus isn't needed ports P0 and P2 are freed up for IO.  I wirewraped a
circuit on sunday and it works great.  The only problem I had was
forgeting to pull EA* high and it wouldn't st

I just got 6 model 90-1230Y-100 100ns battery backed up 32Kbyte static ram from
them for $30 each and a couple of 8kbyte rams (90-1225D-100) for $17 each.
I haven't hooked them up yet so I don't know any problems to look for.

Some other dallas products that look like fun (untried by me!):
DS5000-TK 8051 compatibale with 8kbyte to 32kbyte batter backed up ram
  and real time clock in a 40pin socket compatable with 80C51.  Software
  for pc to download and cable and in circuit download cable.
DS2167K Adaptive data compression design kit - play with compressed audio
DS6417 256kbit to 4megbit nonvolitle serial access ram in a package about
  the size of a credit card.