North Star RAM-16-A Manual page 20

for refresh.
Note 2: Signal is complicated, with many transitions per
loop.
Note 3: Rises during one SMI pulse, falls during the
next, alternately.
actually reference the chip (1/16 of the stores), the
signal goes LOW during the first store and HIGH during
the second.
Note 4: Four pulses per loop, two fetches and two stores.
H. Check the following data output signals on the RAM-16-A.
you are using an oscilloscope, then trigger on ID pin 11 or
the upper end of R10 at 12E (SMI) on the RAM-16-A.
Signal
MD5
MD4
MD6
MDl
MD0
MD2
MD3
MD7
Note 5: Mostly low, high during store cycles outside of
the address range of the board.
I. Replace the 74LS373 at location 17E, replace the 74LS280 at
location 10E if it was removed, remove the jumper wire, and
re-enable the processor board PROM option if it was
disabled.
19
Occasionally two more during stores.
Additionally, for those stores that
Location Description
1 0 . A pin 14
AC, see note 3 above
11A pin 14 AC, see note 3 above
12A pin 14 see note 5 below
13A pin 14 AC, see note 3 above
14 A pin 14 see not 5 below
15A pin 14 see note 5 below
16A pin 14 AC, see note 3 above
17A pin 14 see note 5 below
North Star 16K RAM BOARD
If