On-Line #20 21 января 1996

Железо     Доработки

Iron - Port # FD.

                 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