The table below summarizes the various 6150AD models.
Also, the electronics (hardware) had to develop in time due to changes and progress in technology.
Hardware release 2 became necessary because of the increased functionality of models 6150AD3 and
6150AD4. When hardware release 2 could no longer be manufactured because some of the electronic
components were no longer available, it had to be replaced by hardware release 3. Until now there is a
total of three hardware releases that are summarized in the table below:
logic ICs as SMDs (surface mounted
devices), other parts as »through hole«
types; microprocessor with EPROM
27C32 (24 pins, 4 kbytes).
mostly SMDs; microprocessor with
EPROM 27C64 ... 27C512 (28 pins,
all parts SMDs except transformers and
calibration switches; microprocessor
with flash memory (60 kbytes).