drop of solder - Ode to watch.

AY-Track: MISSION: IMPOSSIBLE (DJ DADO mix)
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(C) Mr. Gluck
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           Ode to the clock

           .........



            The scheme is applied.



                     :-L does not bother me, I smoke ...



   Many years passed and, in my opinion, it's time
about something to tell.


                  Hours.



   Came up with one person (not me)
thought to connect the clock. Since she died, and (thought), 
but I support it. The same man, and presented itself to me for 
experiments m / s 512vi1, providing literature and disappeared,

Here I sat down for a description and I was horrified.
Damn! But a clever thing!

   At first I wanted her to connect as ay,
welfare system is similar to - address register
and data register. Here, I grasped a
bummer - not in a book does not say that
the second mode of access (and there are also
first, but Sinclair realize it would be difficult), after the 
address impossible to disconnect the line CE, or it forget how 
sensitive you want, and will to work with register 0 (seconds), 
and when you try to work with the selected register will 
receive a register of seconds. 

   The second mold grasped me in the operation, when the scheme 
was launched and debugged, stitched ROM, written boot, 
installed a resident in the iS-DOS. According to the obscure 
yet because sometimes (I have a 3-fold) emitted diode, which 
blocks the battery from discharge to five company boards. In 
this case (again, me) all the batteries go into nirvana, and at 
best, merely bent (At worst - one drained), death and 
destruction there. 



   Once again I was down on the batteries, I decided not to 
test fate again, and remove power from the card company, 
feeding clock always on batteries - taking into account little 
current - they should be enough for a couple of years ...


   To date, there are those watch
in a single copy of software and virtually none. BUT! There is 
a ROM, where they regularly ticking, and in my opinion, so far 
(mind you, so far) this is enough.


   Alteration of many programs (mostly
System) prevents ... nothing stops, just do it to no one.

   Not necessarily hang on chsy im2, because
Now precision does not depend on the frequency
Call the program - the ROM at all hours
decoupled with preemption - as can be seen running in no way 
inferior. 

   Now for the iS-DOS. In my opinion, cause
hours each interrupt is not necessary. The information is 
updated once a second, and therefore the latest version of 
Resident reprints time only when replaced by a second and only 
once - it looks it's just as well, but it kills (yes, even here

Kill!) once n hares:

   1) unloaded interrupt that inhibitory iS-DOS'a important;

   2) the probability sglyukivaniya cls'a decreases by 50 times.

   Let me explain: when cleaning the screen ldir'om if it comes 
at the time of transfer interrupt bytes of hours, then the 
entire screen will be filled by one number - it looks 
disgusting. After rework driver effect is practically not 
observed (and the old woman is razdolbuha). 

   Access to the hours performed by setting the 7-th bit port # 
FFFC, otherwise in port space company hours

no.

   After installing the bits in the aforesaid
A possible access to ports Products: -
- # EFF7 - data register, # DFF7 - Register
address.

   In the address register stores the address neobhodimoh cell 
in the data register is written data to be written into the 
installed cell m / s, as well as the data is read from

selected cell.

   It should be remembered that, after dumping the 7 th
Bit # FFFC m / s will forget what you register
established, so work with the clock recommend to conduct the 
below algorithm. 

Example 1, it is the latter.


; Entry in the register
; H-register number, L - number of write


        LD BC, # FFFC

        LD A, # 80

        OUT (C), A
; Enable access to the m / s and set the reg-algebra

        LD BC, # DFF7

        OUT (C), H; establish cell.

        LD B, # EF

        OUT (C), L; puts a value in a cell.

And all turn off

        XOR A

        LD BC, # FFFC

        OUT (C), A

        RET



   Now that it represents
m / sec. For the programmer is in the Device has 64
memory cells, some of which are occupied by official registers.

Address
# 00 - seconds
# 01 - second clock
# 02 - minutes
# 03 - minute alarm
# 04 - Hours
# 05 - Alarm Clock
# 06 - the day of the week
# 07 - the number of
# 08 - month
# 09 - the last two digits of the year
# 0A - business case
# 0B - the same
# 0C - the same
# 0D - the same

# 0E here until the end (# 3F) - RAM users
    converter.
...
# 3F



   RAM user I partially used:

 # 0E - startup mode boot'ov (48/128/vsya
memory);
 # 0F - now do not use (in earlier versions was the attribute 
hours);  # 10 - the number of drive;

 # 11 - B # AA - control the availability of m / s
the necessity of withdrawing hours. Button 2 "
Gluck inverts the byte;
 # 12 - the flag of "user message", if = "G", then
instead of the standard "MR GLUK RESET SERVICE
V5.1 "is displayed messaga of hours.

   It starts at address # 13 and ends at byte # ff, length does 
not exceed 30 bytes, control codes are not allowed (to be taken 
from pzu'shnogo character generator and withdrawn). 


   Now the details. Strictly speaking, an example
A few are not accurate. They can only be used for byte # 0A-# 
3F, and for business process byte clock access to m / s 
neskolno different. 

   The fact that the read / write
may come at the time of updating the information in hours, and 
it happens every second, which is fraught with sideways. 

   To circumvent this situation, there is a special bit in one 
of the official registers, which anticipates the update 
process. If bit = app, then some time (Normalized, but I 
forgot) m / s is guaranteed to not be updated. From practice it 
turned out that this time is sufficient for read / write any of 
the cell. 

   In Gluck, if the update occurs in
hours, the cycle is skipped, this is not noticeable visually 
(clock output more than 1 times per second, although in the 
iS-DOS'e done with that). 


   So after all of the above, it became
it is clear that after picking up the scheme just
in Gluck's clock does not go. What you need to ensure that they 
have gone: 

* Recorded in the # 11 B # AA, in the # 0A-% 00100000,
in # 0B -% 00000010, registers for hours, minutes
and second - time, date, too, is desirable.
M / she considers how many days per month, leap years also 
taken into account, you can automatically on certain days to do 
so, What happens with the translation of summer time

in winter, but I have not used (only
translation is not done, the rest is all by itself.
Also, alarm clock, I have not tried it - I know that
it includes a 5-m bit # 0B, and he did not use). If, however, 
have a desire to use it, on the day of the week and a symbol 
watch, if the alarm included - and suddenly someone you want? - 
So I did.


According to the scheme.



   DD1 - 555LE1, DD2 - 555LL1 as
DD3 555TM8 better use, but you can
TM2, however, TM8 has 4 bits, and TM2 - only two. If you are 
interested in further development of megascreen port, then put 
TM8. 

   Glitch locks RAM over 128 1 st bit
# FFFC, ROM-disc activates the 6 th bit, the 0th bit includes 
additional graphics mode, the fifth bit connects the ROM 
tyrdosa and gives the opportunity to work with registers

SH-shki directly.

   After assembling the circuit there unpleasant
phenomenon - # fffc an even address, and
avoid dryganiya border should put a lock sampling port for 
sample # fe # fffc - all the stones to throw at Pugi because 
such an idiotic address port expansion graphic thought not I, 
but he and I just continued to bits, so as not to enclose the 
new ports. 

   Accuracy can be adjusted for
do this instead of one of the capacitors
put podstroechnik.

   About the ROM-DISCa. Real circuit so I did not. But! All you 
need is in Gluck. Accessed on the following:


* Set the second bit # fffc, which disables the default ROM and 
connects the p-drive, checked byte at 0 if it is not equal to # 
ff (not inserted m / s) and not equal to # f3 (no p-drive, 
standard ROM), then the RST is 0 for a living system;

ie you can use the interface of Gluck (as intended). Thus, 
r-drive has size of 64 kb, which is small, but inexpensive.


   Very promising m / s 27010 (128 kb)
that allows you to have and the p-drive and the main
ROM in a single package, and do not need a circuit switching. 
By harnessing free bit port size P-ROM can be increased to the 
extent necessary. 


   Now all I do is think godforsaken thing.


   By the way, for switching windows p-disk
need a fifth bit # fffc - commutes p A15-ROM, A14 is controlled 
through the port # 7ffd, a bit basic128.

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