Constructor - implementation of PSEUDO-ROM.

 2. PSEUDO-ROM.
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   The meaning of the modification is to sub-
new version instead of ROM with software-accessible
of RAM chips - from one 537 RU10 to
two 537 RU17. In addition, finalization of pos-
allows you to programmatically enable and
turning off TURBO mode.

   The Pentagon owners were lucky again -
in these computers the modification is carried out
with just a few wires and
installation of the 537 RU10 microcircuit instead of 573 RF2
(which is not installed by many anyway).

   Initially, the modification was intended
designed for comfortable hacking and debugging
programs and aroused interest among limited
th circle of users. However, the idea used
used in COBRA-soft programs, can
revive interest in improvement among all
SPECCY holders. The idea is to
placing the COVOX player in a pseudo-ROM.
At the same time, in TURBO mode, the playback speed
guidance is approaching 30 K/s, which ensures
improves the sound quality of digitized music
languages comparable to AMIGA.

   If you are not a big computer fan,
music, then you can indicate other applications
revision considerations: significant (up to 2 times)
acceleration of subroutines, including graphics
physical; hacking games with return to the original
new program to the location of the hack; used
systemCP/M; creating and debugging your own
versions of SOS, DOS and driver
tera; correction of the "magic" procedure;  direct
appeal to 1818 VG93, program initiation
lization of turbo mode, etc.

   If you do not have the Pentagon, then first
it is possible to make modifications to "ZX-COVOX", and
then add the attached diagram to it,
using an unused element TM2.


   The scheme has continuous numbering of elements
com with the ZX-COVOX circuit.

   Signals from the Z80 processor are indicated
in the usual way. If you don't have a routine
"TURBO", then the diode does not need to be installed;
if you don't need the COVOX scheme, then sig-
cash on the 11th pin of D2.2 can be generated
on the 2 remaining unused elements
ments LL1 (-IORQ + -RD + A2).  Signal
BLOCK_ROM is used to block the OS
new computer ROM - it connects to
output 20 or 22 ROM (if they are not
we are on the ground, then the old signal and
BLOCK_ROM should be passed through the
ment LL1).

 What to do in the Pentagon.

   Put 537 RU10 instead of 573 RF2.  For-
connect the -WR signal to the 21st pin of 537 RU10
processor instead of +5V.  Start a signal from
8th pin D67 to turn on the mode
"TURBO" (if available). Start with the process
litter signals -IORQ and -NMI respectively
to pins 2 D65 and 10 D67 instead of the existing ones
signals. Enable modification by earth feed
whether" by 1D65.

   Microcircuit 537 RU17 is different from 537
RU10 only by the number of addresses.  Installed
you can plug it into connector 573 RF2, and to your
Connect signals to the bore terminals with wires.
When installing two RU17 (16 K) on their 22nd
pins -MREQ signal should be supplied
res free elements LL1 respectively
together with A13 and -A13.

 PROGRAMMING. RAM substitution 537
RU10 into the ROM address space occurs
dits when executing a read command from the port
that with address 251 (#FB) or (when enabled)
switch position) when pressed
"magic" buttons. In the second case, simultaneously
There is a transition to address 102
(#66). To return the ROM in any case
you need to execute the read command from
port 123 (#7B). Because volume 537 RU10 sos-
is only 2 K, then its contents are repeated
is repeated 8 times in a row in the first 16 K ad-
forest space. When performing co-
mand from pseudo-ROM is automatically initialized
The "TURBO" mode is activated (if it exists), which
can be used for software installation
new turbo mode.

   The IN A,(251) command is programmed into the "BASIC" ROM
48K" in command processing routines
LLIST, LPRINT and COPY. Entry point addresses
you can calculate it yourself.  Larger
of interest is the entry point with the address
som 102 (#66). From this address you can
insert your own processing programnon-maskable interrupt for hacking and
adjustments to any programs.

   If a program located in
pseudo-ROM, contains a jump to the address
15616, etc., then the control is initialized
floppy drive along with all 1818 ports
VG93. This can be used to write-
Developing your own procedures for working with the disk.
   When fetching commands from pseudo-ROM, no
conflicts between the processor and the video controller.
Therefore, all commands placed there in re-
TURBO mode are performed exactly 2 times faster
tray. This allows you to significantly speed up
execution of programs by placing the most
slower routines in pseudo-ROM.

   To save information in 537 RU 10
after turning off the power, you can do
modification similar to AON's.

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