The Windhover SuperRam 130XE Upgrade By Jay Torres The Windhover Project Copyright(c) 1985, 1986 ALL RIGHTS RESERVED NOTICE:This upgrade is released into the Public Domain for free use of all Atarians. No warranty is given for any damage which results from persons attempting this modification (especially those)who have no experience with hardware. If you are one of those then PLEASE get someone wise to help you. This upgrade may be distributed by any person, BBS, or user group provided credit is given to myself and The Windhover Project. Due to their repeated failures in the past to acknowledge the Windhover Project and myself for the creation of the Windhover 256K SuperRam Upgrade for the Atari 800 and passing it off instead as the Atari800 Plus 256K mod(aka 800/26K Upgrade), this permission is expressly DENIED to David G. Byrd and the South Nevada Atari Computer Club (S.N.A.C.C.) of Nevada. ------------------------------------------------------------------------------------ Due to the architectural design of the new 130XE and the use of the FREDDIE chip (P/N C061991), the XE is very easy to modify as far as memory expansion is concerned. To do this modification, you will need the following parts: 8-41256 Drams(150ns), 1-74LS158 2-to-1 multiplexer,1-33 ohm resistor, and 8-16 pin IC sockets. 1. Open the 130XE casing and remove the mainboard for the internal RFI shielding. 2. Using a desoldering tool and a 10 to 15 watt soldering iron(and braid), remove the 8 64K ram chips from bank #2. Do this carefully so you do not damage the thin traces on the top and bottom of the board. Ram Bank #2 is the right handed bank of ram chips as you look at the board with the RF modulator towards the rear. 3. Solder the 16 pin sockets into the old ram chip locations. Note the notch direction (towards the left edge of the board) if they have them. You will put the 256K chips into them later. 4. Tie together Pin 1 of the ram sockets(from underneath). Use enough wire to leave a 10 to 12 inch leader which you will use later. You can feed this wire thru one of the holes in the board. 5. Carefully desolder pins 15 and 16 of the 6520 chip (P/N C014795) and bend them straight out. 6. Take the 74LS158 multiplexer and bend all but pins 8 and 16 out. 7. Place the 74LS158 chip on top of the 4050 chip located left of center of the board next to the color adjustment potentiometer. Using the soldering iron, connect pins 8 and 16 of the 74LS158 to pins 8 and 16 of the 4050 chip. 8. Using a short piece of insulated wire, connect pin 15 of the 74LS158 chip to pin 8 of the same chip. 9. Using another piece of wire, connect pin 1 of the 74LS158 to pin 30 of the GTIA chip (P/N C014805). 10. Solder another wire from pin 15 of the 6520 to pin 2 of the 74LS158 chip. 11. Solder another wire from pin 16 of the 6520 to pin 3 of the 74LS158 chip. 12. Connect one end of the 33 ohm resistor to pin 4 of the 74LS158 chip. Connect the other end to the wire from pin 1 of the ram sockets you installed earlier. 13. Plug the 256K chips into the sockets. Note the notch direction(towards the left edge of the board). Be careful, they are sensitive to static electricity. A. Place the main board on the table, using a magazine to insulate it. B. Make sure the power switch is OFF. Plug in Power, monitor/TV cables. Turn on Computer. If you get sputtering and then a Blue Screen with "READY" you can go to 'C'. Otherwise, check all of your work, or have someone else do it, then goto A again. C. Turn OFF Power. Install SIO cable and Keyboard(another magazine under). Place DOS disk in Drive 1. Turn ON Power. The disk should boot. You should see "READY". Type DOS, use the dos menu to create and format the ramdisk. You should have 2032 free (128 byte) sectors from the DIR function. Else, check again. 14. Put the main board into the shield, then into the case, then reassemble. Do step 'C' again to test the new ramdisk. D. Find a disk with a large file, such as the MYDOS Doc file. Copy it to the ramdisk. Then copy again(i.e. D8:M1.DOC,D8:M2.DOC). Do several times to fill up ramdisk, then read the last file to make sure the text is still readable. Also, you can find memory test programs that can test all of the bits and bytes. You can use this upgrade with most of the regular DOSes out there. Many commercial programs will at least recognize the 64K XE ram, some will go to 128K, others will use all 256K. This upgrade does not allow ANTIC to follow the banked ram. A switch can be place so that ANTIC following is enabled as needed. For MYDOS:Best to use 4.5.1M. Bank bytes to manually setup ramdisk are:(256K)EF,EB,E7,E3,CF,CB,C7,C3,AF,AB,A7,A3,8F,8B,87,83,0. If wanting to reserve the XE banks for other apps:(192K)CF,CB,C7,C3,AF,AB,A7,A3,8F,8B,87,83,0. end. more instructions and retyped 06Aug2007, RLD