Apple II Misc Hardware Hacking Csa2 FAQs-on-Ground file: F004HDWHACK.TXT The Csa2 (comp.sys.apple2) usenet newsgroup Frequently Asked Questions files are compiled by the Ground Apple II site, 1997, 1998. ftp://ground.isca.uiowa.edu/2/apple2/Faqs http://ground.isca.uiowa.edu/2/apple2/Faqs The Csa2 FAQs may be freely distributed. Note: To correctly view tables and diagrams on a super-res display, use a mono-spaced Font such as CoPilot or PCMononspaced. ____________________________ 001- What's a good hardware project book for the Apple IIe? 002- How can I use a thermistor to read temperature on my A2? 003- Will a prototyping Slot Board fit all Apple II's with Slots? 004- What is the pin-out for the Apple II series Slots? 005- I've been getting Fatal System Error 0911. Is there a fix? 006- Why does my GS Control Panel keep resetting to the defaults? 007- How do I replace my GS "BatRAM" battery? 008- Is there a program to record/restore Control Panel settings? 009- How I can safely clean out dust from my Apple II? 010- How can I safely remove oxidation from IC pins? 011- My System Saver IIgs has gotten very noisy. How can I fix it? 012- What is the mini circuit board near the front of my GS for? 013- How do I add memory to my 1MB Apple IIgs Memory Expansion Card? 014- How can I move my IIgs to a PC tower case? 015- How can I convert a IIgs into a portable IIgs? 016- Where can I get Robot kits to use with my Apple II? From: Paul Guertin 001- Could anyone suggest a good project book for the Apple IIe. I'm interested in using an old box for tracking the temperature in a water bath. Vernier software publishes a book called "How to Build a Better Mousetrap" which contains 14 hardware projects for the Apple II. Project #6 is a temperature probe connected to PDL0. ISBN for the book is 0-918731-16-X. Vernier Software ( http://www.vernier.com ) 2920 S.W. 89th Street Portland, Oregon 97225 USA (503) 297-5317 ---------------------------- From: Sheldon Simms A good book is _Inside The Apple IIe_ by Gary B. Little. It isn't a project book, but it does have a good chapter on using the Game I/O connector for "electronics experiments." ____________________________ From: Cyrus Roton 002- How can I use a thermistor (a resistor which has a variable resistance related to ambient temperature) to read temperature on my Apple II? You can connect a thermistor to a paddle input and supply a voltage to the other end. Current flows through the thermistor to charge a .022 mfd capacitor inside the apple2. When the paddle is read, the apple2 discharges the capacitor and resets a timmer. Then the cap is allowed to charge. When the charge reaches the trigger level (3.2 volts) the timmer is stopped and the count is read out. The lower the value of the thermistor, the faster the charge and the lower the count. Also, the higher the voltage, the faster the charge. A resistance of about 120K with a 5 Volt supply will give a count of about 250. You can add an external capacitor across the paddle input (to ground) to increase the charging time (if needed) The formula is (charge) = (input volts) * (1 - exp(-t/RC)) So, you can use a supply voltage and external capitor as required to fit the resistance value of the thermister (or other resistive component). Probably, the best way to find the correct values woud be to try a variety of values and plot the "count" as a function of the variable resistance. Then compare the plot against the resistance curves for the thermistor (probably not linear), and work out some conversion formula to use in your program to correlate "count" to temperature. ____________________________ From: David Empson 003- Can I use the same prototyping Slot Board for all of the different Apple II's with Slots? Prototyping boards certainly would be the same for the II, II+, IIe, and IIgs. The slots on all slotted Apple IIs are physically identical There are minor differences between the slot signals on the various machines and on some slots in the same machine, mostly affecting rarely used special pins. (See Question 004 for more details on signal differences.) ---------------------------- 004- What is the pin-out for the Apple II series Slots; and, what differences are there in Slot signals from machine to machine? Here is a quick summary of the Apple II series Slot signals: Pin 1: I/O Select ($Cn00-$CnFF, where n is the slot number). Pins 2-17: Address bus A0-A15. Pin 18: Read/Write. Pin 19: unused on the II and II+. On the IIe and IIgs, this has composite horizontal and vertical sync on slot 7, and is unused on other slots, except for slot 1 on the IIe only, which has a diagnostic function to disable the oscillator on the motherboard. Pin 20: I/O Strobe ($C800-$CFFF). Pin 21: this is the RDY input to the micro on all machines, but it behaves a little differently in the IIgs, or in a machine with a 65802 installed. Pin 22: this is the DMA pin on all machines. Again, there are special issues for doing DMA on the IIgs which can cause compatibility problems. Pin 23: this is used for the interrupt daisy chain (out) on all Slots except 7. In the IIe only, this pin can be connected to the GR signal (graphics mode enabled) via a motherboard modificatoin. Pin 24: DMA daisy chain out. Pin 25: +5V. Pin 26: Ground. Pin 27: DMA daisy chain in. Pin 28: Interrupt daisy chain in. Pin 29: Non Maskable Interrupt. Pin 30: Interrupt Request. Pin 31: Reset. Pin 32: this is the INHIBIT pin on all machines. This behaves differently on all three machines: the II and II+ only allow the $D000-$FFFF ROM area to be inhibited. The IIe allows RAM to be inhibited as well, but has strange interaction with main and auxiliary memory. The IIgs only allows this signal to be used if the machine is running in slow mode. Pin 33: -12V. Pin 34: -5V. Pin 35: unused on the II and II+. On the IIe and IIgs, this is the colour reference signal on slot 7 only. It is unused for other slots in the IIe, except for slot 1 where it provides a poorly documented facility to disable the keyboard address decoding. On the original IIgs, slot 3 provides the M2B0 signal (Mega II Bank 0) via this pin and it is unused on other slots. The ROM 3 provides M2B0 for slots 1 to 6. Pin 36: 7 MHz system clock. Pin 37: Q3 - Asymmetrical 2 MHz clock. Pin 38: Phase 1 clock (1.023 MHz). Pin 39: something called "USER 1" on the II and II+, which can be used to disable all I/O decoding if a modification is made on the motherboard. On the IIe, this pin provides the SYNC signal from the micro, which indicates an opcode fetch. On the IIgs, this pin provides the M2SEL signal, which indicates that a valid slow memory access is in progress. This pin must be used by IIgs cards that decode the address without use of the IOSEL, IOSTRB or DEVSEL pins. Pin 40: Phase 0 clock (1.023 MHz). Pin 41: Device Select ($C0n0-$C0nF, where n is the slot number plus 8). Pins 42-49: Data bus D7-D0. Pin 50: +12V. ____________________________ from Rubywand 005- I've been getting Fatal System Error 0911 and when I do the internal diagnostic it gives a system bad : 09010001. Is there a fix? Fatal System Error 0911 and Self-Diagnostic Test 09010001 mean the same thing: You are, very likely, experiencing an ADB Controller malfunction. A guess would be that you are running a ROM-01 GS, probably a ROM-00 machine which has the ROM-01 upgrade. If this is the first time you've noticed the '0911 problem, it is likely that this is the first summer you've owned and used this particular machine. Many early GS's come with an ADB Controller IC which malfunctions over a narrow range of relatively low temperatures. Rooms are normally cooler during summer; so, this is when the error pops up most frequently. Some users first notice a plague of '0911 crashes after adding a System Saver-GS (which increases cooling). '0911 bombs can occur 'any time' but they usually happen at startup and when doing OpenApple-CTRL-ESC accesses to the Desk Accessories (CDA's, Control Panel, ...) menu. As the machine warms up, '0911 crashes tend to become less likely. The bad news is that there is no 100% fix except to replace the ADB Controller IC-- hard to do since it is soldered to the motherboard and, in any case, known-good replacements are difficult to find. The good news is that a very nearly complete cure is not all that much trouble. Since the problem is coolness, the cure is to tape a small 12V bulb (e.g. a 20-30 ma. panel light bulb) to the top of the ADB Controller IC (a square IC near the right front of the motherboard). Use duct tape and try to enclose the bulb and IC in a kind of mini-oven. Run the leads from the bulb to the +12V Fan power pins near the back left area of the motherboard. The idea is to quickly warm up the IC. I used a scheme like this on our early GS and 0911 bombs dropped from 4-5 per day to 2-3 per week. If you can safely power the bulb via an external power module (e.g. a calculator or radio 'AC adapter') so that the bulb can be ON at least a few minutes before powering up the computer, 0911 bombs might disappear entirely. ---------------------------- 006- My GS control panel keeps resetting to the defaults and forgetting the date between power-ups. What's wrong? Most likely, your battery-- also called the "BatRAM battery" needs to be replaced. When the GS is OFF, the battery supplies power to the clock and its attached 256-byte RAM. This small RAM is where Control Panel settings are 'remembered'. If, upon power-up, the GS believes the Control Panel settings have been messed up due to a low battery, it will reset the settings to their default (check-marked) positions. ---------------------------- 007- How do I replace my GS "BatRAM battery"? The standard GS battery is a 3.6V Lithium type rated at 1.2AH. To get to it, you must pop out the Power Supply. If you have a ROM 03 GS, you can slip out the old battery and slip in 'one like it'. On the ROM 01 GS, you will need a Lithium battery with leads you can connect to cut-off leads from the old battery-- about 3/4" each-- remaining on the motherboard. Be sure to mark the "+" lead on the motherboard with white-out. Night Owl Productions used to sell a convenient "Slide-On" Lithium battery made by Tadiran. It came with springy ends that would slip over the cut-off leads from the original GS battery. Radio Shack sells a few models of 3.6V Tadiran Lithium batteries. Mostly, these have smooth ends and are intended to fit into a holder-- for example, one model is "AA" size. Connecting an insulated size AA holder and using a size AA 3.6V battery is one way to handle BatRAM replacement now while making future replacements easier. Another Radio Shack 3.6V Tadiran Lithium battery comes as a small rectangular insulated pack with red and black wires going to a plug. From the catalog illustration, it appears that the plug could be fitted onto the cut-off leads if these were long enough to be shaped to match the plug's connectors. (If you decide to have long cut-off leads, it's a good idea to slip heat-shrinkable tubing over the leads to insulate them for most of their length.) If you like, you can always solder, crimp, etc. insulated leads going to some plug or socket which matches the connector of a particular battery you'd like to use. For connecting bare leads, someone on csa2 suggested using the springy connectors from a Radio Shack electronics experimenter kit to connect a new battery's leads. Another way is to use "wire nuts". Should you do any soldering to the cut-off leads, try to avoid long heat exposure-- you do not want to melt the connection at the motherboard. Make sure that the new battery's "+" lead connects to the "+" lead on the motherboard. Since, possibly, you will be joining bare leads to bare leads, you could end up with more bare wire than you are comfortable with. Check that the bare leads do not touch anything they should not. Bend the leads as required and position the new battery so that nothing will bump into the Power Supply when it is replaced. The usual recommendation for this kind of work is that the computer be OFF. This reduces the risk of damage should a bit of solder, a wire, etc. fall onto the motherboard. GS users are sometimes shocked to discover that a replacement battery may cost $8 to $13. This has led to suggestions that 2-3 standard 1.5V cells in a holder be used. While any number of lower-cost replacement setups can work, this is pretty close to a classic 'you get what you pay for' situation. Regular 1.5V cell combos reportedly crater in about a year. A 3.6V 1.2AH Lithium battery is routinely good for at least 5 years. Our old Nite Owl battery is going on year 7 or 8. That's a lot of years without having to worry about burst and leaking cells or needing to pull the Power Supply and mess with swapping-in replacement cells. ---------------------------- 008- Is there a program to record my Control Panel, etc. settings and restore them after the GS BatRAM battery is replaced? Reference: FAQs Resource file R007BATRAMM.SHK Yes. A number of users have created programs to Save and Restore BatRAM values. The one included as a FAQs Resources file is named "BATRAMMER". It is in file R007BATRAMM.SHK. Use ShrinkIt or GS-ShrinkIt to unpack the file. ____________________________ From: Adalbert Goertz 009- How can safely clean out dust from my Apple II's motherboard, case, and expansion cards? I use a Dustbuster. Block one exit vent and aim the other vent as a blower into the computer. That Dustbuster has strong lungs! ____________________________ From: George Rentovich 010- I'm afraid that oxidation on pins may be causing bad contacts and memory problems. How can I remove the oxidation without resorting to sand paper? Tarn-X works great for removing oxididation from chip pins without a lot of work or risk in harming the chips. Soak the chips in a shot glass until all black oxidation is gone; then, remove the chips and put them in another shot glass with alcohol to rinse. I use a third shot glass with alchol again to be sure and, then, take out the chips and let dry. ____________________________ From: Scott G 011- My System Saver IIGS has gotten really noisy. How can I fix it? It may be that the fan inside the unit is showing wear. The good news is that replacing the fan is an easy and rewarding task. I knew my fan was starting to die when it sounded like it was wheezing during spin-up. The fan, a Sprite model SU2C7, uses sleave bearings, whose lifespan is determined by the lubricating oil supply in the bearings. When enough of the oil evaporates, metal will grind against metal resulting in heat and resistance that cause the fan to quickly lock-up. Better quality fans use ball-bearings, but Kensington apparently used the cheapest component available. Even among the models with sleave bearings, the SU2C7 is the least capable. It can only move 15 cubic feet of air a minute (half what a typical PC fan moves) and has a 55,000 hour rating. In looking for a replacement for my dying fan, I chose to use a better model. The Sprite model SU2B1 has the same dimensions as the SU2C7 used in the System Saver and is readily available from Digi-Key corporation. It uses ball bearings for long life (the fan is rated for 73,000 hours) and can move 28 cubic feet of air a minute. The higher quality is readily apparent: the replacement is currently noticeably quieter than the original even though it is moving more air per minute. To replace the System Saver fan, first make sure the System Saver AC power cord is unplugged. Next, you will need to open the case. Opening the System Saver case involves removing eight screws. You can remove the foam weatherstriping along the periphery of the case to expose the screws OR you can poke through/around the foam at each screw hole. The screw access holes are arranged as shown in the following diagram (bottom view of the System Saver): FRONT ______________________________________________________________ | ________________________________________________________ | | | | | | | * | | | | _____________ | | | *| | | Screw holes revealed ------>|* | | | | | after removing foam | | | | | Fan | | | | | | | | | | | | | | | | | |_____________| | | | *| |* | | | | | | | | | | | | | | | | | | | | | | *| |* | | | | | | | * | | | |________________________________________________________| | |______________________________________________________________| BACK Once inside, the fan can be removed by unplugging the power cord that connects it to the circuit board. A grounding wire that is attached by a screw must also be removed. The fan itself is held to the case by two screws. Once you remove the SU2C7, you can replace it with the SU2B1. Now mount everything back together again with the screws. Apply new foam weatherstripping if necessary. The refurbished System Saver is now better than a factory new model! Notice the difference in sound: a quiet hum rather than a load rumble. If you have a lot of cards, you will notice that the inside of the IIGS is a lot cooler too. An upgraded System Saver is a great way to counteract accelerator instability caused by heat. Sources and parts needed: 1) Part: Sprite model SU2B1 (Digi-Key Part No. CR103-ND) Source: Digi-Key Corp. (1-800-344-4536/www.digikey.com) 2) Part: Foam weatherstripping tape (3/8th inch width, 3/16th inch thick) Source: Home Depot (or a comparable hardware store) ____________________________ From: Rubywand 012- My ROM-01 GS has an odd postage stamp size circuit board tacked onto the motherboard near the front edge. What is the board for? The circuit on the mini-board is a low-gain 1-transistor amplifier which seems intended mainly as a buffer/voltage-level shifter between the 'old Apple' sound output of the Mega Chip and Op Amps which drive the Speaker and Sound jack. On the underside of the motherboard, beneath the boardlette, a surface-mounted resistor (SR1) has been scratched out. Leads from the mini-board run to SR1's connection points as well as Ground and a +12V supply point near Op Amp UM12. The circuit does not appear in the GS 'Hardware Reference ROM-01 schematics; but, it is shown in ROM-03 schematics. Some ROM-01 GS's do not have the mini board; so, it seems likely that the circuit was included on-motherboard in later ROM-01's and all ROM-03's. By the way, the circuit was certainly installed at the time of manufacture and was not part of the standard ROM-00 to ROM-01 upgrade. ---------------------------- 013- I have 256kB on my 1MB Apple IIgs Memory Expansion Card. How do I add more memory? The standard Apple IIgs 1MB Memory Expansion card can be usefully configured for 256kB, 512kB, and 1MB. For 256kB, the top left 8 sockets (i.e. the left half of the top row) should be filled. No jumpers should be placed on the pins near the lower right end of the board. XXXXXXXX-------- ---------------- O O (no Jumpers) 0 0 For 512kB, the entire top row of sockets should be filled. The bottom pair of pins should be jumpered. XXXXXXXXXXXXXXXX ---------------- O O 0-0 Jumper bottom pair For 1MB, all sockets should be filled. The top and bottom pairs of pins should be jumpered. XXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXX O-O Jumper top and bottom pairs O-O To get the full IIgs mem card upgrade to 1MB you can order a set of 24 41256 mem IC's from Alltech (760-724-2404) for $24.00. ____________________________ From: SuperTimer 014- I've heard that some have moved their IIgs's to PC tower cases. Is this hard to do? It is not hard to do at all... I mounted the motherboard with the expansion cards going horizontal in relation to the ground (you need to drill some extra holes in the tower case because the GS has different mounting holes than the PC). The cards are light enough that they stay put this way. The only time this could be a problem is with unusually heavy cards, like the Focus or MicroDrive units... The cards don't line up with the openings on the case, but that's not a problem because Apple cards, unlike PC cards, have ribbon cable extended DB connectors that can be mounted on the openings at the back of the case... For the power supply, I rewired a PC power supply to feed the GS. The voltages are the same, so simply match +5V with +5V, +12V with +12V, -5V with -5V, -12V with -12V, and the grounds and your GS will be ready to run! The PC power supply (250 watts) and fans have a benefit...my GS is more stable now than it was in its native case. I recommend this upgrade for those who feel up to it. Use a full tower case for the best results and most room to work with. ---------------------------- 015- I recently picked up a spare GS from a flea market and would like to convert it into a portable. Has anyone done this? Yes. Tony Diaz has an article describing a couple conversions on his web site at http://www.apple2.org/AppleIIgsPortables.html . ____________________________ From: Erick Wagner 016- Where can I get Robot kits to use with my Apple II? If you have a an RS-232 interface (2400 or 9600bps) you might consider a kit from Lynxmotion ( http://www.lynxmotion.com ). They sell various robot and robotic arm kits that utilize hobby R/C servo motors. Scott Edwards Electronics and several other companies sell devices that allow you to control up to 8 servos per board. You'll have to write all of the software yourself (sending commands to identify a servo and a position value)