Crazy hands - Cache implementation.

            
                       
                       
                                         
(C) 1999 Max/Compu-Sudio Ltd            
-------------------------------------------------------
 Good afternoon! Today I will tell you about
the coolest modification of the Spectrum in the
not programming and hacking programs for
throughout the existence of our computer
ra.  The previous achievement of such a plan
was the invention of a shadowman on Scorpio.
Now everything non-Scorpio people can do
yourself this device and if available
relevant software
become on par with advanced coders
and hackers.                              
   This device is not new - it’s still old -
good Spectrofon`e 17 famous V.M.G.
offered.  But then this device is not
caused a rush of demand. Now, by
As programs are written “for cache”, there are
the number of this device is becoming more and more
necessary. And even prestigious.This text is already morally outdated, but
given that many still deny
are protected from networks, and therefore from “civilized
bathed information market", and even in the
In addition to everything, a diagram from V.M.G. has glitches
in work, then I considered it necessary to touch upon
this topic in his publication.                
                                         
   To begin with, I will list all the advantages that
which this hardware upgrade abounds in:
                                         
 1) 16K of ultra-fast addressable memory
ROM space;                        
   2)  shadow principle of being in the scheme
computer;                              
 3) all addresses that
which are called by RST commands. You can sa-
I can use it for my own purposes, for example
the same RST 8 or even RST 0;             
 4) the most complete access to
VG93 ports, which opens up amazing
from a programmer's point of view, the possibilities of ra-
bots with disk!  What does freedom cost?
Reading register #1F VG-shki for
quality of operation;            
 5) at address 102 or #66 (whichever
off) possibleplace your handler on-
pressing magic, which will undoubtedly simplify
hacking any program that does not use
for its own purposes and not killing it;      
 6) those who like to write their own new OS and
damn, no one needs Windows now
Gut get the fuck out of the main RAM of the computer
pa to the cash, and the entry points to their Mazda
make shells humanly - through
RST`shki!  As in is-dos, for example, but with
this is to use them all, and not just
set the teeth on edge RST 16;                  
 7) many all sorts of possibilities...
                                         
   Disadvantages of having a cache: some Mazda-
they loved old programs (mostly old ones)
make LPRINT txt, which leads to meditation
tions of the entire system. The way out of this is to do it
Before work, install the Lprint ROM
by reading the firmware from the disk and transferring
throwing it into the cache. At the same time, don’t forget to
close/close cache ;)                     
                                         
   So, here isCORRECTEDcache circuit,
which was kindly provided by Master. After
After reworking the circuit, everything began to work correctly
work and do not strain the computer circuit.    
                                         

























   На схеме есть тумблер, который перево-
дит нажатие magic`а в кешor regular dos
and which is convenient to use in various
life situations. I actually have one
situation - I'm breaking the cache or debugging the pro-
gi that I pick or write.            
                                         
 Now some information about the method
bots with cache and an example of its use. Damn,
everything ingenious is simple:                   
                                         
          D.I.                             
          IN A,(#FB) ;cache is open!      
          CALL nn ;user program 
          IN A,(#7B) ;cache is closed!      
          EI ;well, if it’s needed-
          RET ;but...            
                                         
   That's all! There are no stupid LD Sun, #nnn
and OUT (C),n and other nonsense that
published in DEJA VU 7 and other publications,
who gave examples of “expanding RAM” by
16/32K.  That’s also good, of course, but why?
do something that is difficult to write to
software?  Although this is purely my opinion, not pre-
tending to nothing. But the cache is cool
then! And the most interesting thing is all the possibilities
"in one bottle"!                       
                                         
 Programmer capabilities.  They limit
are calculated only by cache size: 2, 4, 8 or
16 kilobytes are implemented in one page,
or how much?You can check this one more time -
nomu. My most primitive method, which is
This allows you to roughly calculate the amount
kilo in cache or determine its absence
in general.                                  
                                         
       DI ;no interruptions!     
       IN A,(#FB) ;open cache            
       LD HL,#0000                     
       LD DE,#0001                     
       LD Sun,#ЗFFF                     
       LD(HL),L                       
       PUSH HL ;clear cache        
       LDIR                              
       POP HL                           
       LD A,#01 ;control byte any,
       LD (HL),A ;except #F3!          
       SR (HL); is there RAM or not?  
       JR NZ,NO_CACHE; no, it’s a pity...   
 LD BC,#ЗFFF;1bKb page size
       INC HL; from address #0001 we are looking for 
       CPIR ;possible repetitions
       LD HL,EXIT ;exit test      
       PUSH HL; that's short ;)       
       LD A,H ;address where there is a
       LD E,#08 ;falls with control 
       SR E                            
       RET Z ;cache at 2K           
       LD E,#10                        
       SR E                            
       RET Z ;at 4K               
       LD E,#20                        
       SR ERET Z ;at 8K               
       POP HL                           
       LD E,#40 ;no matches, know
EXIT IN A,(#7B) ;cheat cache 16K. Rulez! 
       LD A,E ;test result for 
       EI ;further use-
       RET ;nia.                
NO_CACHE                                 
 LD E,0 ;no cache at all!     
       JR EXIT                         
                                         
   As you can see, there is nothing complicated here
and it cannot be.  The cache memory is organized
on in such a way that you can put any
rush without the risk of “flying away”. And use
the entire address space can be
depends on the amount of cache RAM. Let's assume that
you need to make a disk access, but
Unfortunately for you, there are only 2K cash. There's nothing
what's scary about this! The main thing is that the driver
disk operations were not enormously bloated.
Since DOS ports are available when accessing
to window #3D00-#ЗDFF, then the disk driver
operations can be put there too. Open
cache, ldir`nite your driver to the address #3D00
ver and you can freely use it in
for your purposes. Please note that DOS ports
will only be available if the PC is running
cache anywhere (of course, if you
entered the cache through the window), and to access
ports "ZX" need to be connected to the main
RAM. Don't forget this when writing yoursprograms that are supposed to be partially
or cache it completely!          
                                         
   In the appendix to the magazine there is a program
which will help you decide on the availability
the absence or absence of cache, as well as its
volume.  This is "MAGIC INSTALLER". She, co-
Of course, not ideal, but if you have pre-
additional RAM according to any of the known
memory standards, will allow you to feel
yourself as a cool hacker.                     
                                         
   To install the cache you can use
like Soviet microcircuits RU10 or RU17, and
also with bourgeois analogues. Extremely re-
I recommend the chipHY62256ALP-10 32Kb
volume. This is exactly what I have. But mar-
the marking may be different. The main thing is her
volume!                                   
                                         
 Here, however, the “problem” appears:
and what to do with the remaining 16K, unused
bathrooms in the previous scheme? After all, the hands are so
and are itching to use the extra RAM. Come on-
Let's turn our attention to FIDO and look there
answers to questions that interest us. Word
provided to the first person available
century, whose reasoning, in my opinion, is
deserve everyone's attention. So,      
                                         
(C) 1999 Roman Milukov(2:4616/14.29)    
-------------------------------------------------------
 Hello, All!             
                                         
   Some people have questions about
cache-32K. They say it doesn't work. I'm throwing it
corrected diagram.  If it doesn't work
If it melts, it means there is an installation error.           
                                         
               Port #CFF7.               
                                         
   I don’t know about anyone, but after the appearance
a similar scheme from ARC, I now have to
I will definitely block this port in
on your computer!  And it will be turned on after
Toyanno.                                  
                                         
   And once again: Do not connect to this port
RESET is not the best idea. At the same time, at least
and there is no need to write down
every time you restart the desired value
tion, but other problems appear:      
 1. what to do if something bad
the programmer went to him without permission and
did he write in there what he wanted?         
 2. what to do if there is a failure in the re-
as a result of powerful impulse noise? - and in
RAM was important information!              
                                         
         SASNE = 62256         
         =============         
                                         
    It's very easy to install in the Pentagon
CACHE-RAM on 537RU10. Scheme from VMG published
rejoiced in Spectrofon-17.  And not only
for the Pentagon. But with 2K there is little use for it
PS But 16K is a different matter! There's also a story about
Know how to make 16K - on two 537RU17
- they need to be drunk with a “sandwich” on each other
friend. But it is much more convenient to take one drill
Zhui static RAM chip -
62256 (different companies call them differently)
Well, I haveNMB2256LP).             
                                         
    This is where a “serious” trial appears.
Lema - 62256 has a volume of 32K. Well 16K for-
We act as expected. Where would I use it?
thread remaining 16K? A thought immediately comes to mind
address them with bit 4 #7FFD. But all the su-
existing cache software was written taking into account
that for any value of this bit
we have the same cache! Sometimes it's like this
necessary!  Therefore _you can't_ just 1st
catch your leg on bit 4 #7FFD!             
                                         
 I decided to do this on my computer:  
                                         
(Fig. 1) 





























 The link is given to Pentago-chips
on!  Signals: /DOSEN - 11n. D83 (1n. ROM
27512); ROM - 12n. D62.                  
                                         
    Don't forget on the 26th leg 62256 for-
drive A13 (bus A0-A15) from Z80, to 2nd -
A12, on the 23rd - A11. (On the 22nd there should be
/RD.  And the rest of the legs are connected like
at the ROM.)                                  
                                         
   28th leg - food, if served
it as indicated, then the information is in the stat.RAM
will be saved when the power is turned off
until the battery runs out.  A consumes
static RAM in storage mode VERY
not enough. (This is why 1SSLL2 was used!).
For non-Pentagon there is one subtlety. Here
V.M.G. diagram:                            















 Here the last element LL1 must be replaced
thread for element 1SSЛЛ2 and resistor 1K
(LL2 has an open collector output), and
connect its output to the output of the same name
circuit shown in Fig. 1. Or you can here
apply the LP8 element, as in the Pentagon. a
The 13th and 10th legs of KP11 (Fig. 1) must be
give a signal from the 6th leg of TM2, to the 1st
leg LL2 (Fig. 1) - serve from the 3rd leg
LL1.                                     
                                         
   Instead of series 1533 you can put 555.
You can, of course, put the toggle switch on 1-
1st and 15th legs KP11 and work with your hands,
but it's better to do this:                    
                                         
 bit1 and /bitХ are bits of port #CFF7,
obtained this way:              








 Who has collected GLUK-clocks for finalization?
In this scheme, there is already a decoder. (And pita-
The reference to 62256 can be taken from there.)        
                                         
   Now, if the port is reset, we have
that CACHE 16K (1st page 62256). Nor-
small!  If you set bit 4 on the port
#CFF7, then we have CACHE-32K, where the senior
address - bit 4 #7FFD.                     
                                         
   If you load it into a normal CACHE-16K,
for example, TR-DOS 5.04T (in ROM I have si-
dit TR-DOS 5.12F by REANIMATOR), then install
By updating bits 4 and 1 #CFF7, you can use the program
critical to the TR-DOS version. At the same time,
You will also have a cache - the 0th country will connect
Nice!                                    
                                         
   Bit 0 of port #CFF7, when set,
will deny programs access to this port until
pressing RESET (if necessary).            
                                         
   There is another interesting possibility -
connect legs 2 and 11 of KP11 (Fig. 1) here
this way:                           
   
   
   
   
   
   
   
 Then you can load it into the CACHE- pages
32K, for example, NeOS and its own version of bey-
sika-48, set bit 2 #CFF7 and they
will take the place of BASIC-128 and standard-
go BASIC-48. Recording in them becomes
no it is impossible.                          
                                         
                 -------                 
                                         
Max: there is still no uniform standard for
cache-32K, so everyone more or less fumbles
electronics expert invents his own bicycle
ped.                                     
                                         
                 -------                 
                                         
       Variation on a theme        
      CMOS=clock byGluck.      
                                         
   I had to fill out a diagram according to which I
I made myself a watch. Look - maybe someone will
will come in handy.  Please pay attention to
that this IS NOT another stan-
Darth!  Addressing according to the Gluck standard,
just a little tougher, which, in my opinion,
useful.                                 
                                         
   CMOS clock. I recommend for use.   















Signals from legs 2 and 3 TM8 can be given
to the circuit of additional graphics re-
bench press 512*192 px. Then from that circuit
Only KP11 and IR23 are hidden.               
                                         
   Actually, the connection diagram for the legs is 18,
20, 22 is a little incorrect, but that’s how it is
works. That’s how it was with Gluck, and I did it for myself.
I was so lazy - I was too lazy to do it right.
(True, Gluck's watch is powered ONLY from
batteries 4.5V)                            
                                         
 But for good reason it should be like this:               
                                         
     
     
     
     
     
     
     
                                         
                          All the best.
               Best regards, Roman Milukov.