Difference between revisions of "Dragon 32 - CPU and PSU Modifcations and Compatibility"
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'''CPU TYPES''' | '''CPU TYPES''' | ||
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16x16 | 16x16 | ||
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OKI | OKI | ||
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PIGGY BACK | PIGGY BACK | ||
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SIEMENS | SIEMENS | ||
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'''PSU TYPES''' | '''PSU TYPES''' | ||
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MK1 - 1286 Modulator | MK1 - 1286 Modulator | ||
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MK2 - 1233 Modulator | MK2 - 1233 Modulator | ||
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MK3 - 1287 Modulator | MK3 - 1287 Modulator | ||
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'''PSU COMPATABILITY''' | '''PSU COMPATABILITY''' | ||
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MK1 PSUs now no longer manufactured. | MK1 PSUs now no longer manufactured. | ||
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MK2 PSUs are obsolete and when encountered should always be replaced with MK3 boards. | MK2 PSUs are obsolete and when encountered should always be replaced with MK3 boards. | ||
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MK3 PSUs now used for all CPUs. | MK3 PSUs now used for all CPUs. | ||
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'''NOTE:''' | '''NOTE:''' |
Revision as of 23:14, 18 March 2009
Since the introduction of the Dragon 32 there have been several versions produced of both the Central Processing Unit (CPU_ and the Power Supply Unit (PSU).
Now all versions of the CPU will work with the MK3 PSU; this service sheet identifies which modifications are necessary to implement this.
CPU TYPES
16x16
OKI
PIGGY BACK
SIEMENS
PSU TYPES
MK1 - 1286 Modulator
MK2 - 1233 Modulator
MK3 - 1287 Modulator
PSU COMPATABILITY
MK1 PSUs now no longer manufactured.
MK2 PSUs are obsolete and when encountered should always be replaced with MK3 boards.
MK3 PSUs now used for all CPUs.
NOTE:
For PAL B computers use a normal 16x16 CPU with a MK3 PSU, the PSU only needs the sound altered from PAL A reception. This is done when PSU is checked and setup at PSU work station.
Contents
MK3 PSU with 16x16 CPU
With the 16x16 CPU all mods (except possible add on capacitor to position C58) are completed at time of manufacture. Mods as listed below:-
CPU:
15K resistor (Brown, Green and Orange) to plate through hole which leads to IC12 PIN 10 (Sony Mod.) or for neatness resistor mat be fitted from C28 negative side to solder plate on IC12 Pin 10 line. 6.8K resistor (Blue, Grey and Red) from solder pad near C6 to bottom of R6. If background lines are prominent, fit 220N capacitor in C58 position (Not done at time of manufacture). 220R resistor short circuited across R9 (R9 being 270R). Alternatively replace R9 with 120R.
PSU:
Remove existing 1.2K resistor in position R1 and replace with 330R resistor. Remove existing 120K resistor in position R6 and replace with 22K resistor. Retune modulator sound core.
MK3 PSU and OKI CPU
CPU:
15K resistor (Brown, Green and Orange) from Pin 4 IC10 to Pin 10 IC12 (Sony Mod.) 220N capacitor in position C21. Cut resistor R6 and solder single cone wire to cut end, then solder other end of wire to pin 14 IC11. 150 OHM resistor (Brownm Green and Brown) short circuited over R9. Drill back of board to open circuit track.
PSU:
Remove existing 1.2K resistor in position R1 and replace with 330R resistor. Remove existing 120K resistor in position R6 and replace with 22K resistor. Retune modulator sound core.
MK3 PSU and PIGGY BACK CPU
CPU:
15K resistor (Brown, Green and Orange) from Pin 4 IC10 to Pin 10 IC12 (Sony Mod.) 220N capacitor in position C3 Cut resistor R6 and solder single cone wire to cut end, then solder other end of wire to pin 14 IC11. 150 OHM resistor (Brownm Green and Brown) short circuited over R9. Drill back of board to open circuit track.
PSU:
Remove existing 1.2K resistor in position R1 and replace with 330R resistor. Remove existing 120K resistor in position R6 and replace with 22K resistor. Retune modulator sound core.
MK3 PSU and SIEMENS CPU
CPU:
15K resistor (Brown, Green and Orange) from Pin 4 IC10 to IC12 PIN 10 (Sony Mod.) or for neatness resistor may be fitted from C28 negative side to solder plate on IC12 Pin 10 line. 220 OHM resistor short circuited over R9. 6.8K resistor (Blue, Grey and Red) from bottom of R6 to solder plate near positive side of C28. This resistor needs to be sleeved.
PSU:
Remove existing 1.2K or 68R resistor in position R1 and replace with 330R resistor. Remove existing 120K resistor in position R6 and replace with 22K resistor. Retune modulator sound core.