Dataman S4 - Manual (Page 8)

DATAMAN S4 MANUAL
8 Introduction to S4
2. Remove the 1M static RAM chip from
its socket.
3. Substitute a 4M static RAM chip or
module.
4. Replace the back of the case and the
screws.
When you switch on, S4 will now tell you that
you now have 512k of memory instead of 128k.
The ZIF Socket
The ZIF (Zero-Insertion-Force) socket is used
to load new library programs into the TPA
(Transient Program Area) as already described.
The ZIF socket is also used to hold PROMS
when programming. S4 can use PROMS much
the same as a computer uses a disk-drive: they
are a permanent storage medium, which
contains programs to be loaded into system
RAM - such as the program loaded from the
LIBRARY ROM.
When the socket is not being addressed, no
power is applied to it. PROMS can be inserted
at any time, except during an operation like LIB,
LOAD, BURN, TEST, SUM or COMP, which
read the PROM. When S4 is waiting for a
command, or performing any function which
does not involve reading a PROM, the socket
is "cold" – it has no supply voltages. Even
when the socket is being addressed directly, it
is only powered-up for sufficient time to read
the data
Note: PROMS with 24 pins or 28 pins must
be inserted at the bottom end of the socket