IRON
(C) Kirill Gromov CHUNG Software (FFC)
SOME REFLECTIONS ON THE PORT # FD
Yes, a long time since we have not met in the "ON-LINE".
And now my thoughts to the articles of authors on the port #
FD. First, a bit of criticism: you should never "CUSTOMIZED"
COMPUTER Soldering to the program! Simply do the opposite.
Understandably, This does not apply to special programs,
compatibility with the company SPECCY - a sacred thing! But, in
my opinion, someone Honichu easier to change a couple of masks
in the source of his "HONEY COMMANDERA", than a lot of people
climb into their "PROS" and "Scorpio" with a soldering iron,
concerned manic idea to open a RAM disk to 412Kb.
And now actually on the port # FD. Indeed, the problem of
incomplete address is quite sharp. In "Profiles" is a button ON
/ OFF, but what if you want to work in STS, and at the same
time dispose of megabytes of memory? Output is fairly simple,
but has certain nuances of which will be discussed below.
LE1 LI1
ADR1 a 'C_CMR1 (# DFFD)
o
ADR13
LE1
____
IORQ 1
__ O 0
WR
LE1 LA3
ADR1 a 'C_CMR0 (# 7FFD)
o o
ADR15
Here is a fragment of the control circuit configuration port.
LE1 LI1
ADR1 a 'C_CMR1 (# DFFD)
o
ADR13
LI1
'
ADR15
LE1
____
IORQ 1
__ O 0
WR
LE1 LA3
ADR1 a 'C_CMR0 (# 7FFD)
o o
ADR15
Here is the minimum possible scheme is fairly obvious
changes.
This scheme gives the team can safely use OUT
(# FD), A to switch between pages of the port # 7FFD, while not
causing a "trigger" port # DFFD.
Disadvantages:
1. Inquire in the A is # DF, then the result is obvious.
2. Since the port # FD cunning economists also used for
programming music. processor (such as digitizing type BLAVA
128), the result of this manipulation will be sufficient
placheven.
But I personally think that the minimal scheme as a whole
compensates for these shortcomings, at least 128 and STS SHOCK
work well with pressed button ON / OFF.
If the same is fully decode port # DFFD, then the situation
with the number # DF avoid the battery still does not succeed,
but once housing on the board will stand. In this same scheme
is used only one additional element of "I", which can be found
at board.
I think the "Scorpion", the situation is not much harder,
but about This let them have a headache from its creators.
Programmers and hackers, I would have proposed to amend the
existing program of changes to their work on any type of
extended memory, and how to do it in specific programs to
describe and to send any computer publications. I think it
would put an end to the cries of the type "BA-A-A-CK! Bring
your 100-watt soldering iron, I have the" PROS "in the"
conversion "512 kilobytes not plow!"
I wish you success!
CHUNG Software
28.12.1995
