AY-Track: "LAMERZ MUST DIE!"
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(C) Prusak
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Emulator ROMs
Computer "ZX-Spectrum".
Version 1.0.
This development is intended for debugging and testing of
embedded software computer software. This scheme replaces the
ROM on the computer RAM size of 64 KB. I computer owner Profi,
so all signals are indicated on the basis of his scheme.
Therefore bring transcripts of some names, ie
since the schemes of different car models, they may differ.
TRDOS - one of the two signals switch
Pages ROM. When it is active,
connects that half of the ROM, in which
Torah contains the TR-DOS and start
Boc menu Profi.
ROMCS - is active when you contact the following addresses:
# 0000 - # 3FFF, if the ROM does not advance of the
intended kirovano.
ROM14 - the second signal switching pages
Rom. Comes with a port # 7FFD.
The emulator software controlled by the port # F7. Conflicts
with other devices not created because the address decoding
over all 8 bits. The layout of bits is as follows:
0 - connects the RAM instead of ROM. Record in
RAM is only possible when it plugged
Research Institute.
1 - write lock in memory. Useful for
full emulation of ROM.
2 - blocking relief ustroystva.Esli this
bit is cleared, then press the reset button
will connect back to ROM. Under the condition
tanovlennom bit of relief could not be
affect the status of the device. Exit
from this state is only possible by
software reset this bit, or
way off. Also introduced
for a complete emulation of ROM.
3 - Setting this bit to 1 will be connected
chat the page RAM or ROM, in which
contained TR-DOS, and there is something else in
Depending on your machine. You
Bor specifically TR-DOS or additional
Noah page 4 is a bit far
is the # 7FFD. Introduced to facilitate sufficient
parameters to the page TR-DOS, as well as to ensure
baking access to additional countries
boundary in machines, in which it is not (Pro
fi, GRM, radon, etc.).
This device is intended for the use of ROM 27512.
Unfortunately, for many reasons I can not realize your device
with ProfPZU on Scorpio. Naturally, the very ProfPZU to work
with him to be, but Here the replacement of all the pages can
be done. Therefore, in the 4 page of RAM to work need to
download older versions of Shadow monitor, work with
conventional ROM. Second similar case is the interface
"ZX-LPRINT". If his program is located in the separate ROM and
not in the fourth page 27512, this ROM is also not emulated
be. When you install the emulator, ROMs, located in the
computer, you must rearrange his platu.Shema designed to
connect to the system bus. No additional signals are required.
At the moment, the emulator built and running, so the scheme
should not contain errors. Prototype showed brilliant
results. Now you can do with
its ROM anything. For example, you can completely change the
NMI handling routine in TR-DOS - this hitherto worthless button
can be a truly magical!
Prototype testing showed
only a nuance that relates the work
TR-DOS in memory. During initialization, TR-DOS ROM connects to
the place. This phenomenon - a consequence of the routines with
addresses of 15672, which aims to check if the Interface-1. To
do this, it clears port # F7, hoping to get an answer
from the interface. Below is her full
Text:
15672 XOR A; zero the port # F7
OUT (247), A
IN A, (247); consider his condition
CP 30; interface-1 is responsible?
JR Z, 15,684, and if so, create it
; System variables
CP 1931
RET NZ; if not, return
15684 RST 8; creating system variables
; Variables interface-1
DEFB # 31
LD A, 1, is written by the command SAVE
; Vat 1 copy
LD (23791), A
RET; Returns
To ensure the work of TR-DOS memory
emulator must correct this routine zanesya two zeros at the
addresses 15673 and 15674. After that, the port # F7 stops
null.
FD
; (If you have not read, then
; SORRY).
