ATARI 65XE - 320KB RAM.

By Administrator at April 19, 2011 01:04
Filed Under: Atari

ATARI 65XE - 320KB RAM.


Toto je len pár riadkov práve na typ ATARI 65XE. Tento typ nevlastním, preto len takto stručná informácia. Nič nie je občas jednoduché a tak prerábka ATARI 65XE  na 320KB RAM je o niečo zložitejšia ako je to u ATARI 800XE.

Info: prerábka je len pre skúsenejších, aby ste si nezničili počítač !



Pretože tu nie sú dve rady pre pamäte je potrebné napájkovať nové RAM 41256 na pôvodné pamäte, pričom sa vyhne pin 15 a tie sa potom navzájom prepoja medzi sebou a potom spolu s MMU. Tak isto obvod GAL CO25953-20 je potrebné umiestniť priamo na základnú dosku, najlepšie sa priamo napájkuje (iba pin 16 +5V a pin 8 - Gnd), ostatné nožičky sa vyhnú nahor a priamo sa potom prepájajú s ostatnými súčiastkami, to isté sa týka aj multiplexoru. Ako sami vidíte, je tam toho "drátovania" podstatne viac - aj práce je viacej, ale ak budete postupovať pekne bod za bodom dielo by sa malo podariť. GAL CO25953-20 je ten horný obvod obložený bužírkou, druhý obvod pod ním je multiplexor (74LS158, alebo 74LS157).



S najväčšou pravdepodobnosťou  je možné nahradiť multiplexor typu LS za obvod 74HC157, alebo 74HC158 - zatiaľ som to netestoval.



Na nasledujúcej stránke je úprava ATARI 65XE, tu je pekne vidieť že tu je len jedna rada pamätí a preto sa musia pripájať  nové pamäte ako druhá vrstva na pôvodné - tzv. "piggy back" riešenie, z nižšie uvedenej  stránky sú prevzaté aj obidva obrázky prerábky ATARI 65XE na 320KB - link (polish):

http://www.arsoft.netstrefa.pl/ares.htm

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Na uvedenom linku nie je priamy popis rozšírenia, sú tam len obrázky a tak teda

pridávam popis priamo od autora - Scotta Petersona:

(Ja už len dodám že obvod 74LS158 môžeme smelo nahradiť obvodom 74LS157, interne v RAM čipoch bude adresovanie iné, ale na funkciu to vplyv mať nebude.)


The 65XE 130XE/320K Upgrade!

by Scott Peterson


I have written the following documentation in such a manner that you can use it to help you keep track of your progress as you assemble this memory enhancement. Simply place a check in the space provided as you proceed. This

will allow you to readily follow your progress, and pick back up where you left off if you should have to stop.

Once you have finished this upgrade you will then have in your possession an Atari 65XE with 320K of total ram. This is broken down into chunks of 64K of standard ram, and 265K of page mapped ram. This upgrade is 100% compatible with the previous 130XE/320K upgrade and therefore will run all programs that the earlier enhancement ran.


Disclaimer:


The Author nor this BBS claim any responsibility for any type of damages incurred by do this modification


The equipment you will need is:


A: A medium sized Phillips head screwdriver.


B: A very small jeweler's screwdriver with flat blade.


C: Soldering wick (recommend Chem-Wik .100 inch size), or vacuum desoldering

pump.

D: Soldering station (like Weller model WTCP), or LOW wattage soldering pencil of the 15-25 watt variety.


E: Small pair of needle-nosed pliers.


F: #30 gauge wire (Jameco #130 BE)


G: Wire stripping tool for #30 gauge wire ("Clip and Strip" Jameco #CAS-130).


H: Heat shrink tubing or black electrical tape (tubing preferred).


I. Small pair of wire snippers.


J: Optional: Small carpet sample or blanket.


The parts you will need are:


A: Z1-------> 74LS158


B: Z2-------> CO25953 (Custom chip by Atari)


C: Z3-Z10---> 256K Ram chips #41256-150 (8 required)


D: R1,R2----> 33 ohm 1/4 watt resistors (2 required)


And here we go.................


1.___Place carpet sample or small blanket on a clean, uncluttered workspace that is well lighted.


2.___Situate all tools and parts on one side of your workspace.


3.___OPTIONAL: Get a fresh cup of coffee!


4.___Place 65XE face down on carpet. Remove all screws holding cabinet together. Turn unit over. Remove top of cabinet and lay it in a safe place.


5.___Gently pull upward with fingertips on mylar extending from keyboard and remove it from its connector. Place this keyboard assembly with the top of the cabinet. Place screws in a small container so they won't be misplaced.


6.___Take needle-nosed pliers and turn all twist tabs on metal shield so it may be easily removed. Remove all screws from outer edges of PC Board and then place screws in your container, and the top and bottom shields along with the bottom of the cabinet should be placed with the rest of the 65xe cabinet.


7.___Place all ICs in front of you and proceed with the following:


a.___Bend up pin number 15 on all 8 of the 41256 rams. Then snip off the thin part of the leg so all you have left of pin 15 is the "stub" or fat portion. Do this on all 8 rams.


b.___Bend up all pins with the exception of 8 and 16 on the 74LS158. Leave the legs on 8 and 16 long, and snip the thin part off all other pins on this chip.


c.___Bend up all pins with the exception of 8 and 16 on the CO25953. Leave the legs on 8 and 16 long, and snip the thin part off all other pins on this chip.


d.___Take both 33 ohm resistors and snip the leads so their is 1/4 of an inch of lead left on either end of each of these resistors.


e.___Place these chips to one side, and position the 65XE motherboard in front of you. Locate IC numbers U9 through U16. You will find them running along the left side of the motherboard. Take a piece of tape or a small black

magic marker and place a small mark next to the IC that is labeled U12. You see the wisdom of doing so later on in this documentation.

8.___Proceed to piggy-back ICs Z3 thru Z10 inclusive on top of ICs U8 thru U15 inclusive. Please take your time and be sure that each chip is facing the same direction as the integrated circuit below it. Do a good job soldering so not only will this upgrade work well but also will be pleasing to the eyes when you show it off to your admiring friends!


9.___Cut 7 small pieces of #30 gauge wire, and use these to connect all 8 of the pin 15s of the piggy-backed rams.


10.___Gently turn the 65Xe motherboard over exposing the underside to your trusty soldering iron. Cut 7 more small pieces of #30 gauge wire and then proceed to jumper all the pin 1s of the rams. Cut another piece of #30 gauge

wire approximately one foot long and solder it to pin one also and then run it through a convenient hole in the motherboard. Turn the motherboard back up with parts side once again smiling up at you.

11.___Grasp the 74LS158 and proceed to piggy-back it on top of an IC on the motherboard labeled U24 which you will find at the front right of your computer. Make sure it is facing the same direction as the chip you are placing it on top of and proceed to solder pin 1 of the 74LS158 to pin one of U24. Next solder pin 16 of the 74LS158 to pin 16 of U24.


12.___Grasp the CO25953 IC and proceed to piggy-back this gem on top of U2. U2 can be found approximately in the dead center of your 65XE motherboard. Again, please make sure both chips are facing the same direction.  Remember, a slow, sure job is often-time the fastest job overall! Proceed the solder pin 1 of the CO25953 to pin 1 of U2. Next, solder pin 16 of CO25953 to pin 16 of U2.


13.___Grasp one of those 33 ohm resistors you have previously trimmed and solder one end to pin 15 of Z3. Z3 you ask? Why that is the chip which has been piggy-backed on top of U12. U12---you know that one! that's the chip

we so wisely marked before we started!

14.___Cut a short piece of wire and attach it to the free end of the resistor you just connected to Z3 pin 15. Run the other end of this wire to the CO25953 pin 10.


15.___Grasp the other 33 ohm resistor and solder it to the 74LS158 pin 4 (this is one of the ones you have previously piggy-backed.) Now take the long piece of wire you had previously connected to all of the pin 1s of the rams

and solder this to the free of your resistor.

16.___Now take the metal bottom and place the motherboard back into this protective housing.


17.___At the front of your computer on the lefthand side you will find R108. Desolder the end of this resistor closest to the front end of the computer. Solder a short wire to the new free end of this resistor, put heat shrink on the connection, and connect the wire to pin 11 of the CO25953.


18.___Our next chore is to locate U6 which can be found near the center of the front end of the motherboard. Please be careful as the traces on this pc board are very delicate and will not be able to tolerate much abuse. Gently

desolder pins 23 and 24 of U6. The best way to do this is take your solder wick, place it against the leg to be desoldered,and heat it until you see the solder beginning to flow into the wick. Turn the motherboard over and make sure all the solder is off of the pin on this side also. Repeat this step with pin 24 also. Then take a small, flat-bladed jeweler's screwdriver and use it to push the pins back and forth a bit. This will free up the pins andallow you to remove them easily and not tear the living daylights out of the board! Turn the motherboard back with the parts side up, and use that same jeweler's screwdriver to pry pins 23 and 24 of U6 out of the board. Leave them extended in horizontal direction, snip the thin part of the leg off, thus leaving the fat parts of these 2 legs for you to connect to later.

19.___Cut a small piece of wire, and strip either end. Connect one side of this wire to the land where pin 23 of U6 used to be. Fasten the other end of this wire to CO25953 pin 1.


20.___Cut a small piece of wire, and strip either end. Connect one side of this wire to the land where pin 24 of U6 used to be. Fasten the other end of this wire to CO25953 pin 2.


21.___OPTIONAL!:Get your second cup of coffee.


22.___Cut a short piece of wire, strip both ends, and connect one side to the 74LS158 pin 1, and the other side to U17 pin 30.


23.___Cut a short piece of wire, strip both ends, and connect one side to the 74LS158 pin 2, and the other side to U23 pin 15.


24.___Cut another short piece of wire, strip both ends, and connect one side of this wire to the 74LS158 pin 3, and the other end goes to U23 pin 16.


25.___Cut another short piece of wire, strip both ends, and connect one side to the 74LS158 pin 15, and the other end to pin 8 of the same chip.(74LS158)


26.___Cut yet another short piece of wire, strip both ends, and connect end of the wire to CO25953 pin 6, and the other end to U6 pin 35.


27.___Cut another short piece of wire, strip both ends once again, and connect one side to CO25953 pin 7, and the other end to pin 8 of the same chip. (CO25953)


28.___Cut another short piece of wire, strip both ends once again, and connect one side to CO25953 pin 9, and the other to U17 pin 26.


29.___Connect one end of this wire to CO25953 pin 12, and the other side to U6 pin 23.


30.___Cut a short piece of wire, strip both ends, and connect one side to CO25953 pin 13, and the other end goes to U6 pin 24.


31.___Cut a short piece of wire, strip both ends, and connect one end to CO25953 pin 14, and the other end goes to the same chip pin 16.(CO25953)


32.___Cut yet another short piece of wire, strip both ends, and connect one end to CO25953 pin 15, and the other end goes to U6 pin 5.


33.___Cut another short piece of wire, connect one end to CO25953 pin 3, and the other end goes to U23 pin 12.


34.___Cut another short piece of wire, strip both ends, connect one end to CO25953 pin 4, and the other end goes to U23 pin 13.


35.___Cut one final piece of wire strip both ends, connect one side to CO25953 pin 5, and the other end goes to U23 pin 14.


36.___Check all your wiring, and rearrange it to be pleasing to the eye as well as functional.


37.___Get your SpartaDos 3.2 that has the RD.COM file on it, say a prayer and load 'er up! If it boots you probably are ok! If not, don't panic, simply go back through section step by step, you will find it is probably some little error or oversight.


38.___While you have your computer open it would be a good idea to solder thejoystick jacks, the monitor, I/O and power supply ports also. It may save you a bit of aggravation later on!


39.___Reassemble your upgraded computer by placing the top metal cover back over the motherboard. Turn all twist tabs and then insert the appropriate screws. Gently plug the keyboard back in, position it in its slots in the

cabinets, and then place the cabinet top on. Turn over and insert all screws. While you have it out, why not use a bit of cleaner on it to make it sharp! If you don't have SpartaDos, then Run, don't walk to your favorite computer store and get it!

For you programming types, here are the control numbers for location 54017 (PORTB).


________________________________________

Bank #     Control #   Hex #

________________________________________
Bank   1 ------>131----->83
Bank   2 ------>135----->87
Bank   3 ------>139----->8B
Bank   4 ------>143----->8F
Bank   5 ------>163----->A3
Bank   6 ------>167----->A7
Bank   7 ------>171----->AB
Bank   8 ------>175----->AF
Bank   9 ------>195----->C3
Bank 10 ------>199----->C7
Bank 11 ------>203----->CB
Bank 12 ------>207----->CF
Bank 13 ------>227----->E3<--|130XE
Bank 14 ------>231----->E7<--|130XE
Bank 15 ------>235----->EB<--|130XE
Bank 16 ------>239----->EF<--|130XE

________________________________________

It is recommended to use SpartaDos 3.2, but you can also use MYDOS 4.1 or higher, and also Topdos 1.5 and higher with the 320k series of upgrades.


Enjoy your 320K 65XE!


Scott Peterson

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A zase toto je na dnešok všetko, majte sa, kto sa do tej úpravy pustí želám pevnú ruku pri pájkovaní a dobrý výsledok na konci práce..

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Volám sa Igor Gramblička, bydlisko: Bratislava, Slovakia. Môj nick: Igi. Blog je o mojich záujmoch - som už na dôchodku, predtým som pracoval ako IT špecialista na počítačové siete a redakčné systémy vo viacerých denníkoch - až som pred rokmi nakoniec zakotvil v jednom denníku kde som to potiahol až do konca mojej profesnej kariéry.