System Booster

home *** CD-ROM | disk | FTP | other *** search

/ System Booster / System Booster.iso / Archives / HardwareProjects / ioexpansion.lha / Docs / Assembly.man < prev next >

Wrap

Text File | 1991-01-28 | 33.7 KB | 747 lines

28 January 1991 ASSEMBLY MANUAL FOR THE AMIGA I/O EXPANSION BOARD ©1990,91 The Puzzle Factory, Inc. INTRODUCTION This project will enable you to inexpensively add two parallel ports and two serial ports to your Amiga 500, 1000 or 2000. Furthermore, you can easily and inexpensively upgrade to four parallel ports and/or four serial ports at any time. The hardware consists of a small printed circuit board with a 40 pin cable and DIP jumper that plugs into the socket occupied by CIA B, and a small pcb that contains the serial interface. CIA B is physically moved onto the I/O Expansion board. DISCLAIMER This is a simple hack, and if you get the bare boards, or a parts kit, you should have no trouble putting it together and having it running on your Amiga in short order. You do not need to understand how this board works to enjoy using it, but it will help if you have to fix it. If you do have problems, or fry your beloved Amiga, it's your problem only. Because the RF shield is modified in order to install this board (on an Amiga 1000), it's your responsibility to comply with FCC regulations concerning RFI. If your neighbors complain of RFI on their TV sets, you must solve the problem. If you have no experience soldering or handling electronic components, don't try this project as your first one! I may be able to help with some problems that you run into. I check BIX regularly, and my email address is jblavin. Alternately you can call my BBS, The Symposium, at (503) 935-7883. While every effort has been made to make these instructions as accurate and complete as possible, neither Jeff Lavin or The Puzzle Factory, Inc. accepts any responsibility arising from any inaccuracies contained herein. ASSEMBLY NOTES We suggest that you print this file so that you can take advantage of the "check" boxes provided at the left to help keep track of your progress. Please read and understand each section before you begin work. You will finish sooner, the board will cost you less, and we'll all be happy. Before you start to assemble this project, make sure you have all the tools necessary to do the job properly. You will need: 1. A small (15-25 watt) soldering pencil, preferably temperature controlled. 2. Good electronic quality 60/40 alloy rosin core solder. A diameter of .031" will work well. 3. Small needle-nose pliers. 4. Small diagonal cutters. 5. Wire strippers. 6. Tools for dealing with the insulation displacement connectors (IDCs). If you do not have access to a press, please use a smooth-jawed vise to press on the IDCs, and work very carefully. Do not use pliers. 7. Integrated circuit pin straightener. You may also need one or more of the following tools in order to mount the connectors for access to the outside world: 1. 1/4" drill and various sized bits. 2. Chassis punch or nibbling tool. 3. Utility knife. Due to the small foil area around some circuit board holes and the small areas between pads, you must use care to prevent solder bridges between adjacent pads. Use only the minimum amount of solder and do not heat components excessively. It is also very important to keep the soldering pencil tip clean and well tinned. The electronic components are intended to be inserted into the side of the printed circuit board that contains white screen printing. When installing electrolytic capacitors, make sure that they are oriented properly. In all cases where polarized capacitors are to be installed, the square pad will mark the positive lead. Take care to orient integrated circuits properly, too. In many cases, installing an IC backwards may irreversibly destroy it, wasting both money and time on a replacement. In all cases where ICs are to be installed, a square pad marks pin 1. We strongly recommend the use of sockets for all integrated circuits used in this project. When installing integrated circuits into their sockets, especially 40 pin ICs, be very careful to see that all the pins actually go into the slots in the socket. ICs come from the manufacturer with the rows of pins slightly bent out to facilitate the use of automatic insertion equipment. Before you can insert the ICs by hand you must bend the rows of pins back to an approximately 90 degree angle. This can best be accomplished by the use of an inexpensive pin straightener. When pressing IDCs onto ribbon cable, make sure that the cable is accurately alligned inside the connector so that there is not excess cable on one side and an unused contact on the other. Also be careful to press the connector on straight. A sufficient angle may cause a contact to make connection to two lines. I/O EXPANSION BOARD ASSEMBLY The following parts will be necessary to complete the I/O Expansion Board. Please see the end of this manual for sources: Part # Description ------ ---------------------------------- [ ] PCB1 I/O Expansion Board printed circuit board [ ] U1 8520 integrated circuit (From Amiga) [ ] U2, U3 R65C22P1 VIA integrated circuit (2 ports each) [ ] U4, U5 R65C52P1 DACIA integrated circuit (2 ports each) [ ] U6 74F139 integrated circuit [ ] U7 74LS90 integrated circuit (Optional for MIDI) [ ] X1 3.6864 Mhz crystal [ ] OSC1 5.0 Mhz TTL clock oscilator (Optional for MIDI) [ ] R1, R2 1K 1/4W 5% resistor [ ] C1, C2 18 pf disc capacitor [ ] C3 22 uf 6.3V decoupling capacitor [ ] C4-C10 .01 uf decoupling capacitor [ ] P1 20x2 pin dual-row socket header, gold [ ] P2, P3 20 pin single-row male connector, gold [ ] P4, P5 10x2 pin dual-row socket header, gold [ ] J1, J2 3 pin single-row male connector, gold [ ] J3 2 pin single-row male connector, gold [ ] S1, S2 Shorting jumpers, gold inlay [ ] SO1-SO5 40 pin DIP socket [ ] SO6 16 pin DIP socket [ ] SO7 14 pin DIP socket (Optional for MIDI) This parts list is for building a 4/4 port board. Depending on which set of parts you order, and whether you are building 2 or 4 ports, you may receive fewer parts than this. Unpack the printed circuit board and carefully inspect it for damage. TPF will not exchange circuit boards that have been partially or fully assembled under any circumstances. Start Assembly [ ] Solder five 40 pin sockets SO1-SO5 at U1-U5. [ ] Solder a 16 pin socket SO6 at U6. [ ] Optionally solder a 14 pin socket SO7 at U7. If you are not planning to use the MIDI capability, this part may be left out. [ ] Solder X1, the 3.6864 Mhz crystal. Be careful that the metal can does not touch the foil pads on the board. [ ] Optionally solder OSC1, the 5.0 Mhz TTL clock oscilator. If you are not planning to use the MIDI capability, this part may be left out. [ ] Important note: If you are planning to use the MIDI capability, you must install a jumper on the back of the PCB connecting together pins 3, 6 and 10 of U7. 30 gauge wire-wrap wire will work well in this application. A trace was inadvertantly left off the PCB and the MIDI clock will not function without this connection. [ ] Solder 1K 1/4W 5% resistor R1 and R2. [ ] Solder .01 mf decoupling capacitors C4-C10. [ ] Solder 18 pf disc capacitors C1-C2. [ ] Solder 22 uf decoupling capacitor C3. The square pad indicates the positive lead. Be especially careful of solder bridges when soldering the following connectors: [ ] Solder P1, the 20x2 pin dual-row socket header. [ ] Solder P2, the 20 pin single-row male connector. [ ] If a 65C22 is to be installed at U3, solder P3 in the same manner as P2. [ ] Solder P4, the 10x2 pin dual-row socket header. [ ] If a 65C52 is to be installed at U5, solder P5 in the same manner as P4. [ ] Solder J1, the 3 pin single-row male connector. [ ] If a 65C52 is to be installed at U5, solder J2 in the same manner as J1. [ ] Solder J3, the 2 pin single-row male connector. [ ] Cut two pieces of wire about 8 inches long. 28-30 gauge stranded wire will work well here. We suggest you use two different colors of wire. [ ] Attach one end of each wire to the two square posts of J3, labled A14 and A15. These may be soldered directly to the posts, or a 2-position socket connector may be used to aid in subsequent disassembly. [ ] Install shorting jumper S1 onto J1 at this time. If OSC1 and U7 are installed, place the jumper over pins 1 and 2. If OSC1 and U7 are not installed, place the jumper over pins 2 and 3. pin 1 2 3 pin 1 2 3 _______ _______ | . . . | | . . . | |_______| |_______| J1 J2 _______________ _______________ | | | | | Top of U4 | | Top of U5 | | | | | | | | | [ ] If a 65C52 is to be installed at U5, install jumper S2 onto J2 in the same manner as S1. [ ] Clean excess flux off the back of the board. Depending on the type of flux used, rubbing alcohol or laundry detergent may do the trick. Both methods are reasonably safe. Use stronger solvents at your own risk. Put the cleaned board somewhere warm, not hot, to dry. [ ] Place the board on a conductive surface. Aluminum foil will work well for this purpose. [ ] Install a 74F139 IC at U6. [ ] Install one R65C52P1 DACIA at U4. [ ] Optionally install the other R65C52P1 DACIA at U5. In order for the software to work properly, if only one 65C52 is used, it must be installed at U4. [ ] Install one R65C22P1 DACIA at U2. [ ] Optionally install the other R65C22P1 DACIA at U3. In order for the software to work properly, if only one 65C22 is used, it must be installed at U2. [ ] Optionally install a 74LS90 at U7. If you are not planning to use the MIDI capability, this part may be left out. [ ] Place the I/O Expansion Board aside for the time being, leaving a conductive material in contact with the back of the board. End Assembly INTERFACE BOARD ASSEMPLY The following parts will be necessary to complete the Interface Board. Please see the end of this manual for sources: Part # Description ------ ---------------------------------- [ ] PCB2 Interface Board printed circuit board [ ] U1, U2 MAX238CNG integrated circuit [ ] R1, R2 1K 1/4W 5% resistor (Optional - see text) [ ] C1, C5 4.7 uf 25V capacitor, charge pump [ ] C2, C6 4.7 uf 25V capacitor, charge pump [ ] C3, C7 10 uf 25V capacitor, charge pump [ ] C4, C8 10 uf 25V capacitor, charge pump [ ] P1 20x2 pin dual-row socket header [ ] P2, P3 25 pin right-angle pcb male sub-D connector [ ] SO1-SO2 24 pin DIP socket on .300" centers Please note that this parts list will build 1 Interface Board, which will provide 2 ports. For 4 serial ports, 2 Interface Boards are required. Unpack the printed circuit board and carefully inspect it for damage. TPF will not exchange circuit boards that have been partially or fully assembled under any circumstances. Start Assembly [ ] Solder two 24 pin sockets SO1 and SO2 at U1-U2. [ ] Optionally solder R1 and R2, 1K 1/4W 5% resistors. These components are used to pull up CTS, and are only necessary if you will be connecting the serial port to a device that does not assert CTS. The 65C52 ICs will not transmit if CTS is not asserted. This is implemented in hardware and must be addressed in hardware. Be very careful of the orientation of the folowing capacitors: [ ] Solder 4.7 uf 25V capacitor C1, C2, C5 and C6. [ ] Solder 10 uf 25V capacitor C3, C4, C7 and C8. Be especially careful of solder bridges when soldering the following connectors: [ ] Solder P1, the 20x2 pin dual-row socket header. [ ] Install P2 and P3, the 25 pin sub-D connector, into the component side of the board. If you want to use female DB-25 connectors for any reason, these must be installed into the back of the board. Attach the connectors to the board using four 4-40 x 5/16" pan head screws and nuts. After tightening the fasteners, solder the connectors to the board. [ ] Clean excess flux off the back of the board. Depending on the type of flux used, rubbing alcohol or laundry detergent may do the trick. Both methods are reasonably safe. Use stronger solvents at your own risk. Put the cleaned board somewhere warm, not hot, to dry. [ ] Place the board on a conductive surface. Aluminum foil will work well for this purpose. [ ] Install one MAX238CNG at U1 and the other at U2. [ ] If an R65C52P1 DACIA is installed at U5, assemble the other Interface Board in the same manner as this one. [ ] Place the Interface Board aside for the time being, leaving a conductive material in contact with the back of the board. End Assembly CABLE ASSEMBLY The following parts will be necessary to complete the Cable Assemblies. Please see the end of this manual for sources: Part # Description ------ ---------------------------------- [ ] N1 20x2 pin dual-row socket connector [ ] N2, N3 10x2 pin dual-row socket connector [ ] CA1 40 pin DIP plug with 9" 28 ga. ribbon cable, rainbow [ ] CA2 20 conductor, 28 ga. ribbon cable, rainbow Please note that this parts list will connect the I/O Expansion Board to 1 Interface Board, which will provide 2 ports. For 4 serial ports, more parts are required. Please read the INSTALLATION section before assembling the cables. Start Assembly [ ] Begin by determining how long a 40 conductor cable you will need to go from P1 on the I/O Expansion Board to the socket occupied by CIA B. We strongly urge you not to make this cable any longer than 8", and the shorter the better. Cut the cable, CA1, to this length. [ ] Note that one end of this cable already has a 40 pin dip plug installed for you. Press the 20x2 pin dual-row socket connector, N1, onto the unterminated end of cable CA1. Set aside. [ ] Determinw how long a 20 conductor cable you will need to go from P4 on the I/O Expansion Board to P1 on Interface Board. This cable may safely be made 2-3' long, but be aware that if the cable passes outside of the computer cabinet, it may cause excessive RFI. Cut a piece of the cable, CA2, to this length. [ ] Press the 10x2 pin dual-row socket connectors, N3 and N4, onto the ends of this cable. Set aside. [ ] If a 65C52 is installed at U5, assemble another cable in the same manner as this one. Set aside. End Assembly SERIAL CABLE ASSEMBLY Though not strictly part of our project, a serial cable will be required for each serial port you plan to use. We recommend that these cables be constructed according to the following directions for general purpose use. You may want to construct cables using 15 pin sub-D connectors for special purposes. The following parts will be necessary to assemble one serial cable. Please see the end of this manual for sources: Designation Description ----------- ---------------------------------- [ ] P1 25 pin male solder-cup sub-D connector [ ] P2 25 pin female solder-cup sub-D connector [ ] CA1 8 conductor shielded cable w/drain Start Assembly [ ] Tin terminals 1-8 and 20 on the 25 pin sub-D connectors. [ ] Strip and tin wire ends of the cable CA1. [ ] Solder the cable to the terminals as follows: Name P1 P2 ==== == == GND 1 1 TXD 2 2 RXD 3 3 RTS 4 4 CTS 5 5 DSR 6 6 GND 7 7 DCD 8 8 DTR 20 20 [ ] Install connector shells, and tighten hardware. End Assembly PARALLEL CABLE ASSEMBLY Though not strictly part of our project, a parallel cable will be required for each parallel port you plan to use. We recommend that these cables be constructed according to the following directions for use with printers, and most parallel devices. You may want to different cables for special purposes. There are four possible units associated with the eightbit.device, as follows: Unit 1: U2, Port A -> P2, pins 1-10 + ground Unit 2: U2, Port B -> P2, pins 11-20 + ground Unit 3: U3, Port A -> P3, pins 1-10 + ground Unit 4: U3, Port B -> P3, pins 11-20 + ground For the purposes of this explanation, we will assume that you will be constructing a cable using port 3. The following parts will be necessary to assemble one parallel cable. Note that the parallel cable, unlike the serial cable, is assembled in two parts: part 1 runs from the I/O Expansion Board to a local connector (possible the computer's rear apron), and part 2 connects the local connector to the printer or other device. Please see the end of this manual for sources: Designation Description ----------- ---------------------------------- [ ] PP1 20x1 pin single-row socket connector [ ] PP2 25 pin female solder-cup sub-D connector [ ] PP3 25 pin male solder-cup sub-D connector [ ] PP4 36 pin female Centronics type connector [ ] CA1 11 conductor ribbon cable [ ] CA2 11 conductor shielded cable w/drain Start Assembly [ ] Tin terminals 1-10 on the 20x1 pin single-row socket connector. [ ] Tin terminals 1-11 and 17 on the 25 pin sub-D connectors. [ ] Tin terminals 1-11 and 16 on the 36 pin female Centronics type connector. [ ] Strip and tin wire ends of both cables, CA1 and CA2. [ ] Solder cable CA1 to connectors P1 and P2, and solder cable CA2 to connectors P3 and P4 as follows: VIA Signal PP1 PP2 PP3 PP4 (These are the above designations, === ====== === === === === not connector designations) CA2 STROBE* 2 1 1 1 D0 DATA0 3 2 2 2 D1 DATA1 4 3 3 3 D2 DATA2 5 4 4 4 D3 DATA3 6 5 5 5 D4 DATA4 7 6 6 6 D5 DATA5 8 7 7 7 D6 DATA6 9 8 8 8 D7 DATA7 10 9 9 9 CA1 ACK* 1 10 10 10 - GROUND PAD 17 17 16 [ ] Install connector shells, and tighten hardware. End Assembly INSTALLATION OF I/O EXPANSION BOARD & INTERFACE BOARD A500 Installation ================= Remove power from the Amiga. Remove the screws securing the cover and remove the cover from the Amiga. Remove the keyboard. On some A500s the keyboard connector is not polarized, so note it's orientation. You don't have to remove the disk drive, but it will help if you unplug it's cables from the motherboard and fold them out of the way. Toward the back of the motherboard are the two CIAs. Gently pry CIA B out of its socket (that's the one closest to the disk drive), and install it on the I/O Expansion Board at U1. Be careful to orient it correctly. After installing the I/O Expansion Board and Serial Interface Board(s) (see "Mechanical Installation"), remove the conductive material from the board and carefully insert the 40 pin DIP jumper on the end of cable, CA1, into the CIA B socket, ensuring that all 40 pins line up correctly. Then connect the 20x2 socket on the other end of the cable onto the header at P1 on the I/O Expansion Board. As long as you are careful and don't use excessive force, you should have no problems with this part of the installation. Now we're going to connect the two wires we attached to J3 earlier. These wires bring A14 and A15 into the address decoder. These signals are not available from the CIA socket, so we must look elsewhere. A good place to pick up these signals is from the ROM. Unfortunately, there are a number of different motherboards made for the A500. The best way to determine where A14 and A15 are located on the ROM is to take an ohmeter and find out which ROM pins are connected to pin 42 (A14) and pin 43 (A15) on the CPU. The corresponding pins on the ROM should be somewhere around pin 36. Some of the A500 schematics are incorrect as to the location of these signals on the ROM, so it's best to check! Solder the wire from the pad marked "A15" on the I/O Expansion Board to A15 on the ROM, and solder the wire from the pad marked "A14" on the I/O Board to A14 on the ROM. This just about completes the electronic installation. (Skip to "Mechanical Installation".) A1000 Installation ================== Remove power from the Amiga. Remove the plastic cover from the Amiga base unit. Admire all the names. Remove the RF shield and set aside. You don't have to remove the disk drive, but it will help if you unplug it's cable from the motherboard and fold it out of the way. Just in back of the internal drive are the two CIAs. Gently pry CIA B out of its socket (that's the one closest to the daughterboard), and install it on the I/O Expansion Board at U1. Be careful to orient it correctly. Remove the conductive material from the board and place it on the left side of the Amiga, near and to the rear of the three custom chips. Carefully insert the 40 pin DIP jumper on the end of cable, CA1, into the CIA B socket, ensuring that all 40 pins line up correctly. Then connect the 20x2 socket on the other end of the cable onto the header at P1 on the I/O Expansion Board. As long as you are careful and don't use excessive force, you should have no problems with this part of the installation. Now we're going to connect the two wires we attached to J3 earlier. These wires bring A14 and A15 into the address decoder. These signals are not available from the CIA socket, so we must look elsewhere. A good place to pick up these signals is from the back of the daughter board. A15 is located at U2L, pin 10, and A14 is located at U2K, pin 13 (see Diagram 3). Solder the wire from the pad marked "A15" on the I/O Expansion Board to U2L, pin 10, and solder the wire from the pad marked "A14" on the I/O Board to U2K, pin 13. This just about completes the electronic installation. (Skip to "Mechanical Installation".) A2000 Installation ================== Note: The following installation was done on a Rev 4.2 motherboard. Other motherboards may be somewhat different. Remove power from the Amiga. Five screws hold the case together, 4 on the sides and 1 at the back. Unscrew them and slide off the top part of the case. Make a sketch indicating the orientation of all cables connecting the drive bay and the motherboard and/or other cards (such as hard drive controller cards), then unplug them. Remove the power supply/drive bay by unscrewing 2 screws in front and 4 in the back. At this point the motherboard should be completely exposed. Underneath where the power supply was, before you removed it, are the two CIAs. Gently pry CIA B (labeled U301) out of its socket, and install it on the I/O Expansion Board at U1. Be careful to orient it correctly. One of the most difficult decisions you will have is where to mount the I/O Board. The location you choose will be affected by how crowded your 2000 is, whether you have a board in the CPU slot, etc., so it's not possible to give definite instructions. Note that this decision will affect how you'll want to assemble the 40-pin DIP jumper, so hold off the construction of this cable until you have resolved the board's final location. One idea is especially attractive: Mount the I/O Board on a bare Zorro card, or maybe even a real Zorro card (a HD controller with unused space reserved for a hard disk would be ideal). This will give it sufficient mechanical sturdiness, and make it extremely easy to obtain A14 and A15 as well as additional power and ground lines. After you have determined where the I/O Board is to be installed, remove the conductive material from the board and install it. Assemble the 40 pin DIP jumper cable, CA1, and carefully insert the DIP plug into the CIA B socket, ensuring that all 40 pins line up correctly. Then connect the 20x2 socket on the other end of the cable onto the header at P1 on the I/O Expansion Board. As long as you are careful and don't use excessive force, you should have no problems with this part of the installation. Now we're going to connect the two wires we attached to J3 earlier. These wires bring A14 and A15 into the address decoder. These signals are not available from the CIA socket, so we must look elsewhere. There are only a few sources of A14 and A15 in the 2000. The unbuffered signals are available at the 68000/68010, the ROM, and Agnus. The use of the unbuffered address lines is not recommended. Instead, grab A14 and A15 from U601 (an 74LS245) or one of the 100-pin "Zorro II" slots, as follows: U601 A14 - pin 12 ---- A15 - pin 11 "Zorro II" slot A14 - pin 41 --------------- A15 - pin 43 This just about completes the electronic installation. Mechanical Installation ======================= Note: As the following section was written primarily for an A1000, only some portions will be applicable to other Amigas. We encourage you to read this section even if you own an A2000. Most of the remainder of the work is of a mechanical nature. At this point you must make some decisions. First of all, decide exactly where and how you want to secure the I/O Expansion Board in place. In my own A1000, I set one end of the board on top of the power harness, and supported the other end with plastic standoffs. Where do you want to mount the connectors for the serial ports? You will find that the four D-subminiature connectors will fit handily over the existing row of connectors on the Amiga's rear apron (see Illustration 1). Each serial interface board connects to the I/O Expansion Board with a 20 pin ribbon cable and header sockets. The first two ports, Port 1 and Port 2, are connected to P4 on the I/O Expansion Board, while Port 3 and Port 4 are connected to P5. What kind of connectors do you want to use for the parallel ports? You could use D-subminiature connectors for the parallel ports if you can find a way to tell them apart from the serial ports. Centronics-type connectors are another option for the parallel ports. After deciding what type of connectors to use, either solder or crimp ribbon cable to them, as appropriate, and install them temporarily. Experiment with different wire routings until you are satisfied with the arrangement. Now attach the other end of the ribbon cable to the I/O Board connectors, making sure to attach grounds to the two ground pads provided near pin 1 of P2 and P3. Whatever connectors you do end up using will have to be installed somewhere. You will need to make cutouts for the connectors, and also cutouts in the RF shield. One option may be to just leave the shield off entirely, but remember that you are responsible for any RFI that results from your modifications. This completes the installation. Debugging ========= Note: The following section was written primarily for an A1000. With the exception of references to Kickstart, most of the remainder will be applicable to other Amigas. Before you start permanently attaching things to your Amiga, you will want to try things out. For simplicity, you may apply power to the I/O Expansion Board without having the Interface Board(s) connected. If you power up, and nothing at all happens, i.e. the screen doesn't change color - the power LED may not come on, etc., turn the power off immediately, as you probably have a short circuit. Visually inspect the board, and if you find nothing wrong, remove all the chips, except for the CIA at U1, and temporarily insert a jumper from U6, pin 1 to U6, pin 7. This will have the effect of making the CIA look electrically to the Amiga as if the I/O Board wasn't there at all. Try powering up again. If you get the Kickstart disk icon this time, you can pretty well suspect a bad IC, or a missing signal (or ground). One other thing you may try at this time is to solder a 10K resistor between the reset pin of any of the chips U2-U5 and +5V. On some Amigas the built-in pull-up resistor may be insufficient. If none of these remedies get you running, it's hardware debugging time, and I wish you luck. If the Amiga does all or any of the following: 1. Refuses to accept the Kickstart disk 2. The disk drive chatters and buzzes 3. Refuses to read the Workbench disk 4. Reads Workbench properly, but access light goes on and off, drive double-steps, etc. it is possible that you may be experiencing some noise problems, depending on when your Amiga was made. The first thing to suspect in this case is the PAL's on the daughterboard. Run additional ground and +5V busses to all 4 PAL's and both tower sockets. If this doesn't do the trick, run an extra ground lead directly to the I/O Expansion Board at the pad marked "-" adjacent to P1, pin 1. A +5 power lead may also be connected to the pad marked "+" adjacent to P1, pin 39, but should not normally be necessary. This should solve the problem. The only other possibility is to try a new 8520 (or 6526, which is considerably cheaper). A bad CIA is possible in this case, because the signals may be too weak to overcome the extra capacitive loading of the cable. If the CIA worked fine before installing it in the I/O Board, but will not work correctly in the board, try swapping it with the other CIA before buying a new one. CLOCK/CALENDAR BOARD ASSEMBLY The following parts will be necessary to complete the Clock/calendar Board. Please see the end of this manual for sources: Part # Description ------ ---------------------------------- [ ] PCB3 Clock/Calendar Board printed circuit board [ ] U1 OKI MSM5832 Real-time Clock/calendar integrated circuit [ ] X1 32.768 Khz clock crystal [ ] C1 4.7 uf 6.3V decoupling capacitor [ ] C2 20 pf disc capacitor [ ] C3 5-35 pf variable capacitor [ ] R1 2.7K 1/4W 5% resistor [ ] R2 100 ohm 1/4W 5% resistor [ ] D1 1N4000 diode [ ] SO1 18 pin DIP socket [ ] P1 20x1 pin single-row socket connector [ ] B1 NiCad or Lithium battery (see text) Please note that parts for the clock are readily available, but not from us, except for the printed circuit board, PCB3. Unpack the printed circuit board and carefully inspect it for damage. TPF will not exchange circuit boards that have been partially or fully assembled under any circumstances. Start Assembly Please refer to the IFF file, "Clock_Diag.iff" while assembling this board for correct parts placement. [ ] Solder R1, the 2.7K 1/4W 5% resistor. [ ] Solder SO1, the 18 pin DIP socket. [ ] Solder C2, the 20 pf disc capacitor. [ ] Solder C3, the 5-35 pf variable capacitor. [ ] Solder C1, the 4.7 uf 6.3V decoupling capacitor. [ ] Solder X1, the 32.768 Khz clock crystal. Be careful not to let the crystal get too hot. [ ] Solder P1, the 20x1 pin single-row socket connector. [ ] Cut two pieces of wire about 8 inches long. 28-30 gauge stranded wire will work well here. We suggest you use red and black wire for +5V and ground, respectively. [ ] Strip approximately 1/4" of insulation from the black wire. Insert the black wire through the pad indicated, from the component side, and solder. Bend the excess over to form a jumper between the indicated pads and solder. B1 may be either a 3 cell NiCad battery, or a 3V lithium battery. The batteries may be fastened to the component side of the Clock Board with tape, glue, double-sided sticky stuff, Velcro, rubber bands, or chewing gum. Even a battery holder! If using a NiCad battery follow these instructions: [ ] Solder R2 and D1. [ ] Connect the negative side of the battery to the pad marked "-". [ ] Connect the positive side of the battery to the pad marked "B+". [ ] Solder the red wire to the pad marked "V+". If using a lithium battery follow these instructions: [ ] Connect the negative side of the battery to the pad marked "-". [ ] Connect the positive side of the battery to the the pad marked "V+". Install a jumper between the pads indicated. Do not install R2, D1, or the red wire. [ ] Install U1 in S1. End Assembly INSTALLATION OF CLOCK/CALENDAR BOARD Remove power from the Amiga. The Clock/Calendar Board is installed by pushing the header socket over the 20 pin single-row header next to one of the 65C22 VIAs, and attaching power and ground. The ground wire should be soldered close to the header using the ground pad provided. The +5V lead may be connected to any convenient source in the Amiga, and is only necessary if using NiCad batteries. Note that the "Time" program as supplied is assembled to use the VIA at U2, and must be reassembled to use the VIA at U3. The 5-35 pf variable capacitor, C3, is used to set the accuracy of the clock. This may generally be done in a trial and error fashion. As this board is so simple, there is generally nothing to debug. If the clock won't run, either the clock chip, or the crystal must be damaged. This completes the installation. Amiga, Kickstart & Workbench are trademarks of Commodore-Amiga, Inc. =eof=