CPU - OPTION Selects the CPUcore Clock. Depends on the Busclock.
at 40 MHz:
CPUClock
PLL
R24
R22
R9
R2
R23
R21
R8
R1
80MHz
x2
-
X
-
-
X
-
X
X
100MHz
x2.5
-
X
X
-
X
-
-
X
120MHz
x3
X
-
-
-
-
X
X
X
140MHz
x3.5
X
X
X
-
-
-
-
X
160MHz
x4
X
-
X
-
-
X
-
X
180MHz
x4.5
-
X
X
X
X
-
-
-
200MHz
x5
X
-
X
X
-
X
-
-
220MHz
x5.5
X
-
-
X
-
X
X
-
240MHz
x6
X
X
-
X
-
-
X
-
For max. Busperformance avoid odd Divisors like 2,5:1.
X = Rn in place
- = Rn not soldered in
R2, R9, R22, R24 = 4.7K
R1, R8, R21, R23 = 51 ohm
Feature Option
Selects the CPU-ID, MFM-Floppy, GCR- Floppy, PS/2 Ports and 10BaseT.
Pin 11 = H -> Gestalt ID 515
Pin 11 = L -> Gestalt ID 514
All others are currently unknown.
CPU ID
currently unknown
10BaseT on board Ethernet
The Chip used for 10BaseT is a LXT 905 PC.
MFM Floppycontroller
SMC 37c78