TURBO PROCESSOR Z80
ON Pentagon-128 UP TO 7MHz.
(C) V.M.G.
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Without a significant increase in performance
the performance of the ZX-Spectrum computer is practically
it is impossible to solve the two most important problems
dacha: fundamental improvements in graphics and
high-quality music synthesis. At the same time
My experience shows thatL U B O Yprocess
SOR Z80 can work at twice the speed
frequency - 7 MHz, while performing at
all operations are twice as fast, not related -
problems with the operation of RAM. During read operations/
The processor has to write several RAM entries
slow down, giving time to the regeneration cycle
irrationality of the television image. However
and in case of unfavorable sequence
CPU operations performance
usually not lower than 155% of normal
3.5 MHz mode.
Сигнал RAMRQ берётся в Pentagon`е с 12-
ой ноги DDS, инверсный 7MHz - с 9-ой ноги
DD2, 3.5MHz с 8-DD1, а HLD с 28 вывода
1818 ВГ93. Сигнал _WAIT_ и CLK подаются
соответственно на 24-й и 6-й выводы
процессора Z80 вместо старых сигналов.
Для тех, кто предпочитает делать дора-
ботку навесным монтажом,let us point out that D1.3
acts as an inverter and can be
replaced by any free element LN1 from
available on the board, and D1.4 is replaced by
series connected free
elements LL1 and LN1. Now for finalization
only two additional micros are required
circuits that can be soldered onto existing
(D2, for example, on DD15). Another option is
use two free elements LE1 from
modification of RAM to 512K, if any -
Xia ;-)
OPERATING PRINCIPLE AND ADJUSTMENT.
In the "disabled" state on the 9th pin
TM2 is maintained at a high level and multi-
tiplexor KP11 switches to inputs CLK and
_WAIT_ processor respectively 3.5 MHz and
"1". When the switch is closed, then
The 12th pin of TM2 appears low
line, which is transmitted to output 9 TM2 in
moment of coincidence of phases of signals 7 MHz and 3.5
MHz. At this moment the switch occurs
KP11, and now the processor is supplied
respectively 7 MHz and standby signal.
The wait signal is activated at the moment
request by the processor for permission to access
connection to RAM (in this case RAMRQ goes to "1")
and continues until the hardware removes the
dew plus another half beat. Hardware removal
RAM access requestproduce micro-
computer circuits at the moment of switching ad-
resin multiplexers on the Z80.
When you turn on the disk drive motor, the turbocharger
press is blocked by the HLD signal, otherwise it is possible
failures during reading are possible (although not obligatory)
research and recording of the disc. Magazine "Radio Amateur"
#9 from 1994 assures that for some
VG93 copies do not lock turbo mode
needed. Then connect ground instead of HLD.
Make sure your processor is running
without failures at 7 MHz (for example, in
someone else's computer). Many processors have
At this frequency the amplitude is greatly reduced
output signals, and this may be the reason
no failures. In this case, it is recommended
"support" the buses for power supply through a resistor
ry or increase the voltage on the processor.
In the latter option, so as not to overheat
remaining elements, apply voltage with
source (up to 5.6V) directly to
processor, and power the rest of the board with
it through a powerful diode, on which
there will be a voltage drop to the required
possible for the operation of other level microcircuits
at 4.9 ... 5.1V.
If your computer crashes while you are
switching the OFF/ON toggle switch, then on the 11th pin
water TM2 modifications give a signal withexit
free element LL1 on the computer board
ra (DDS2.2 or DDb5.3), and to the inputs of this
element signals 3.5 MHz and C40 from output 6
DD15 chips.
You can slightly reduce the waiting time
on the processor, if on the 3rd leg D2.1
improvements to supply 14 MHz with 4 legs DD1
computer, but not on all computers this
it turns out. You can also try running
run the computer at a frequency of 14 MHz, applying
5 leg D3 refinement of signal C31; in case
positive result of such an experiment
please tell the cop about this car
ru ;-)))
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