Processor Board Assembly; Ram Board Assembly - NorthStar HORIZON Manual

PROCESSOR BOARD ASSEMBLY
You have now completely assembled your computer "mainframe",
including the chassis, motherboard and power supply. Now refer
to the separate instruction manual to assemble the North Star
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ZPB-A processor board. When you have completed those
instructions, return. to the next section of this manual. Note
that a separate Z80 Technical Manual is included in the
documentation with the HORIZON giving a full description of the
operation and programming instructions for the Z80.
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Note that if you are using a processor board other than the
North Star ZPB-A, then some method must be found to force the
computer to jump-start to the bootstrap PROM starting address
on reset and power-on.
RAM BOARD ASSEMBLY
Ycu now have assembled and checked out your HORIZON mainframe and
processor board. Now refer to the separate instruction manual
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fc,r the North Star 16K RAM board . When you have completed those
instructions, return to the next section of this manual.
*
Note that if you will be using memory other than the North Star
RAM-16-A, you must keep in mind the following:
A. Be sure the memory you are using can operate with a Z80.
Some S-100 bus memories will not.
B. If the memory you are using has a protect feature, note
the conflict with bus line 70 described in the Motherboard
Assembly section.
C. If your memory does not work at full speed with a 4MHz
Z80A, be sure and set the wait state logic correctly on
the processor board and/or the memory board.
45 North Star HORIZON Computer