Autor Thema: Techtalk über die TAB 16MB Speichererweiterung von Newell Industries  (Gelesen 2327 mal)

0 Mitglieder und 1 Gast betrachten dieses Thema.

Offline Arthur

  • Benutzer
  • Beiträge: 9.911
  • Mein Atari erinnert mich an die gute alte Zeit..
Ich habe keine Ahnung ob schon jemand diese Board nachgebaut und zum laufen bekommen hat. Diesw Skizze hatte ich auch schon mal im Mega-hz-Thread eingeworfen. Nun habe ich dies Skizze leicht um ein paar Symbole erweitert da ich die Schaltung dann leichter lesen kann.

Der MC68000 der in den ST/STE's steckt hat einen 24Bit Adressbus und kann damit normalerweise 16MByte Adressieren. Durch die MMU werden aber effektiv wohl nur 22 Leitungen zur Adressierung zu Verfügung gestellt und deshalb gehen also nur 4MByte in den kleinen 68K-Atari's.

Ziel einer solchen Schaltung ist also:

1. Die fehlenden 2 Adressleitungen zu erzeugen da mit jedem weiteren Bit sich der zu verwaltende Speicher verdoppelt werden kann. Also unmodifiziert 4MByte mit 22 Leitungen mit 23 dann 8MByte und mit 24Bit dann 16MByte. Es gibt natürlich Bereiche die in dem Adressbereich vom OS schon verwendet werden aber (13-14)MB sind durchaus machbar im ST.

2. Dafür zu sorgen das keine Adressfehler erzeugt werden.


« Letzte Änderung: Fr 22.04.2011, 10:58:26 von Arthur »

Offline Arthur

  • Benutzer
  • Beiträge: 9.911
  • Mein Atari erinnert mich an die gute alte Zeit..
Hier auch noch die zugehörige Readme-Datei (ca. um 1/3 gekürzt):

Inspect the TAB upgrade board for any physical signs of damage or any bad solder joints. This is just a precautionary measure. The boards are inspected before packaging, but damage may occur afterwards.These instructions assume that you are familiar with the computer and its components and have the computer already disassembled.

Installation Instructions
1.  Locate the GLUE chip (CO25915) and cut the traces going to pins 4,5,6,7,8. There may be only one trace going to each pin or there may be 2, depending on the motherboard that you have. These are the A16-A20 address lines respectively. Each one only goes from the 68000 CPU to the GLUE and MMU (CO25912). On some motherboards, the lines come from the CPU to the MMU and then on to the GLUE. In this case there should be only 1 trace to each of the 5 pins on the GLUE chip. On other motherboards, the lines come from the CPU to the GLUE and then on to the MMU. In this case there will be 2 traces to each of these pins (probably 1 on top and 1 on bottom) and both must be cut. In essence, the pins 4-8 at the GLUE need to be taken out of the circuit. Isolated and open. Nothing connected to them. Refer to drawings in back.

2.  If you had to cut more than 5 traces, then you must jumper the A16-A20 address lines to the MMU from the CPU. A16-A20 are pins 44-48 on the CPU respectively and go to pins 11-15 on the MMU respectively. Do this on the bottom side of the motherboard. Use 26-30 guage tinned wire. If you only had to cut 5 traces, then no jumpers are required. Refer to drawings in back for a visual aid.

3.  If available, use an ohm meter to check the continuity between the CPU and MMU, and check that there is no continuity to the pins of the GLUE.

4.  Locate a suitable place to position the TAB board and fan the first 7 wires to reach pins 44-53 of the CPU. Fan the next 3 wires (8-10) to reach the last TOS rom in your system. Fan the last 6 wires (11-16) to reach the GLUE.NOTE: Cut all wires as short as possible to reach their termination point, within reason. No banjo strings please.

5.  Connect wire 1 (the red one) to the capacitor going to pin 1 (+5v) of GLUE.

6.  Connect wires 2-7 to CPU pins 44-48, and 52 respectively.
7.  Connect wires 11-15 to GLUE pins 4-8 respectively.
8.  Connect wire 16 to the other side of the capacitor where you connected wire 1.
9.  It's a good idea to test the computer at this point. Place the motherboard where you would normally place your computer. Make sure it is on a non conductive surface. Connect monitor, power supply, keyboard, and optionally your disk drive and turn the power on. The computer should boot as it would before anything else was done, unless you don't hook up the disk drive, then it will take a little longer and go to the desktop without any icons. If all is well, proceed to next step.


10. Remove the 6 TOS roms chips, and note where they were installed for later reference. If you have the 2 chip rom set, simply remove the old roms and plug the new roms into the sockets, and skip instructions 11-15.

11. On the 128K x 8 bit roms (2.06) strap and solder pins 1,32,31, and 30 together. Bend out pins 2 and 3 to about a 45 degree angle.

12. Install the EO rom in the socket where you removed chip CO26165 (TOS 1.0).

13. Install the EE rom in the socket where you removed chip CO26162 (TOS 1.0).NOTE: Make sure that the exposed 5 pins (1,2,3,31,32) do not short out to anything.

14. Connect wire 8 to pin 3 of both new roms.

15. Connect wire 9 to pin 2 of both new roms.NOTE: Wire 10 does not get connected. It is a spare.

16. Test computer as in step 9. On power up, the Atari logo should appear and after an added delay (for a hard disk to come up to speed) it should start a memory test. Press escape key to bypass the memory test.

17. If all is well, reassemble computer, or proceed to dual TOS optional instructions.Dual TOS Instructions (Optional)If for one reason or another you want to be able to switch between the new TOS and the old TOS the following is required. Do the normal installation FIRST. Then follow the following instructions.

NOTE: If your rom chips are under the power supply, you will have to find some way to raise the power supply about 1/2 inch, or you will have to remove the sockets the dual roms go into and solder the original roms to the motherboard. If you raise the power supply, the case will have to be cut for the plug and power switch. Also the top cover may not fit good and the extra heat closer to the plastic could cause the plastic to melt. You will also probably need to modify your top shield. In other systems check the clearances BEFORE you proceed with these instructions.

A. 6 chip set instructions

1.  Remove the new roms from the sockets (do not disconnect wires) and install your old roms back in the sockets, but bending pin 20 of both old roms out.

2.  Piggyback the new roms on top of the old roms with the exception of pins 3 and 22. These pins should line up with pins 1 and 20 of the old roms respectively. It may be easier to piggyback the roms out of the sockets.NOTE: Pins 20 of the old roms and pins 22 of the new roms are the active low chip select pins and if not in use must be pulled high.

3.  Strap the old roms pins 20 together and connect to +5V through a 10K ohm resistor.

4.  Strap the new roms pins 22 together and connect to +5V through a 10K ohm resistor.

5.  Wire the center post of a SPDT toggle switch to pin 20 of one of the old rom sockets.

6.  Wire one side of the switch to one of the pins 20 of the old roms.

7.  Wire the other side of the switch to one of the pins 22 of the new roms.

8.  Test computer as before. Flip the switch to change the TOS. DO NOT flip switch with POWER ON. If you do, the system WILL crash.

9.  Reassemble computer, and mount toggle switch in an out of the way location to avoid accidental switching, but keep it as close to the roms as possible.

B. 2 chip set instructions

1.  Remove the new roms from the sockets and install your old roms back in the sockets, but bending pin 22 of both old roms out.

2.  Piggyback the new roms on top of the old roms with the exception of pin 22. It may be easier to piggyback the roms out of the sockets.

NOTE: Pin 22 of the roms are the active low chip select pins and if not in use must be pulled high.

3.  Strap the old roms pins 22 together and connect to +5V through a 10K ohm resistor.

4.  Strap the new roms pins 22 together and connect to +5V through a 10K ohm resistor.

5.  Wire the center post of a SPDT toggle switch to pin 22 of one of the old rom sockets.

6.  Wire one side of the switch to one of the pins 22 of the old roms.

7.  Wire the other side of the switch to one of the pins 22 of the new roms.

8.  Test computer as before. Flip the switch to change the TOS. DO NOT flip switch with POWER ON. If you do, the system WILL crash.

9.  Reassemble computer, and mount toggle switch in an out of the way location to avoid accidental switching, but keep it as close to the roms as possible.

Problems

A. If your system doesn't work after you have installed the new roms, check the following.

1.  Make sure the roms are plugged into the proper sockets. From pin 19 of the GLUE, you should have continuity to both roms pin 22. If not, you are in the wrong rom socket banks.

2.  Also check that rom pin 24 of the EO rom has continuity to GLUE pin 46. The EE rom pin 24 should have continuity to GLUE pin 47. If either of these is wrong, you are in the wrong socket.

3.  The red wire from our board is wire #1, and count sequentially to 16 at the other side of the ribbon cable. Don't confuse wire number with the pin number on the plug. They DON'T match up. Wire 1 actually goes to pin 16, wire 2 goes to pin 1, etc. We ALWAYS refer to WIRE NUMBER.

4.  Double check to make sure all wires are going to proper place and without shorts.

5.  Did you test the computer at the suggested intervals. If not, back up and try to isolate the problem.

B. If you use the dual rom option and you are using a TV, and you experience RF interference, using a shielded cable to the switch will help. Ground the shield close to the connections to the roms. DO NOT connect shield to switch.It's more likely to be an incorrect installation than a bad board. There just isn't much on our board to fail. We use FAST TTL logic when normal LS would work. The circuit is proven and rock solid. Check your installation again. We will repair or replace any defective board returned to us within 1 year of purchase.Refer to following drawings at back during installation.

TOS 2.06 FEATURES

  This list of features has been compiled by us, and is intended as a guideline for using the new TOS. It IS NOT a complete description of the DESKTOP, or the TOS 2.06 operating system. It will mention some of the differences between TOS 1.0 & 2.06.

BOOT UP

On boot up, you will notice there is a delay. This is designed to give a hard disk a chance to come up to speed. So you can hook your hard disk & computer to the SAME power switch and turn them on at the same time now.

If you don't touch the keyboard on power up, the new TOS will perform a RAM & ROM test of the system. The time required for this depends on the amount of memory you have. To BYPASS this, simply hit your Esc key anytime after powerup.
« Letzte Änderung: Fr 22.04.2011, 10:59:28 von Arthur »

Offline Arthur

  • Benutzer
  • Beiträge: 9.911
  • Mein Atari erinnert mich an die gute alte Zeit..
Ich finde nicht das dies ein Anfängerprojekt ist >:D...selbst mit einer fertig bestückten Platine gibt es noch einige wenn und aber... Schwer zu verdauen ist auch das hier einige Leitungen auf dem Mainboard durchtrennt werden müssen damit die Schaltung funktionieren kann....

Hier die finale Frage...wenn ihr die Schaltung und die Einbauanleitung berücksichtigt...ist das nur ein Hirngespinnst oder klappt das wirklich?

Offline tuxie

  • Benutzer
  • Beiträge: 6.786
  • Falcon! Milan! Schuetzt die Raubvoegel!
Hi,

ich habs schon nachgebaut! Funktioniert nicht! Es gibt dafür mehrere Gründe!

1. Timing zwischen der erzeugten und der normalen Adressleitungen stimmen nicht überein.! Könnte man eventuell noch hinbekommen.!
2. Alle Adresszellen die über diese Adressleitung angesprochen werden, werden nicht Refreshed.  Das Problem ist aber auch nicht so einfach Realisierbar.

Die Ramleitung zwischen GLUE und MMU muß aufgetrennt werden und der MMU mitgeteilt werden das es sich um Nutzbaren Speicher handelt! Dies kann man über eine einfache Logische Schaltung machen. Ich habs mit einem GAL abgebildet. Habe da auch mehrere Geschwindigkeiten getestet 7ns, 10ns, 15ns.


Tschau Ingo

Offline Arthur

  • Benutzer
  • Beiträge: 9.911
  • Mein Atari erinnert mich an die gute alte Zeit..
Dann kann man sich die Mühe wohl sparen und eher in eine Magnum ST investieren. Hat denn mal jemand ausgerechnet was für eine Verzögerung die Spule L1 mit 4,7uh bewirkt?