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© 1997-2006
Gareth Knight
All Rights reserved



Hardware FAQ

This FAQ is based on information gathered from the relevent comp.sys.amiga.* and demon.tech.amiga newsgroups, FTP and WWW sites and my own personal experience. Others are reworks of questions that have come up ICPUG SE meetings and while I've been giving technical support. Some questions have links mainly to files on the Aminet or pages on other sites. In the cases of Aminet links, most files will be in the hard/hack directory. The questions have be sorted under headings for easier access:

If you have any information to add or correct please e-mail it to me webmaster@basil.u-net.com

Big-Box Amigas

Q. How do I add a second internal floppy drive to my A2000?

A. You will need to physically mount the drive in its bay. Then connect the Power and Data cables. Then you must then close J301.

Q. Can the A4000[T] support 8 Meg of CHIP RAM?

A. There is a jumper (J213) on the mother board which sets the SIMM type for CHIP RAM. This can be set to 8 Meg, but the Alice, and the rest of the AGA chip set, does not yet support 8 Meg of CHIP RAM.

Q. Are the Zorro II/III slots parallel? How are they powered up?

A. The slots are powered up in series from the one closest to the power supply (leftmost in the A2000 an lowermost? in the A3000/A4000). For this reason it is important to add FAST RAM into the first slot so that it is available when other cards (especially hard disk controllers) are recognised. If FAST RAM is found then such cards' drivers will be loaded into FAST RAM, giving a considerable speed increase.

Q. I get no mouse movements on my A1500 (A2000). I've tried a different mouse, but the problem remains. All other IO devices work, so the CIAs are not faulty. How can I fix this?

A. Based on information from Trouble.txt on the Aminet, you should check the 74LS175 (U202). Sometimes the mouse port can come loose from the board. If this is the case, replace the port, by soldering another onto the board.

Q. What is the Amber Chip for?

A. Amber is the custom de-interlacer chip found in the A3000. It is also found on the 2320 Flicker Fixer for the A2000. This card uses the video slot.

Q. What is the 26 way internal connector, behind the serial port in the A2000 for?

A. It's an internal serial port for use with certain internal MIDI interfaces. It has no real use as if you connect a PC style serial port header, the port will still be addressed as serial.device, unit 0

Q. How do I add a second internal floppy to an A3000[T]/A4000?

A. You will need to use a three way cable, which as a twist in it for one connector. Plug this connector with a cable twist into DF0: (so that it remains DS0) and plug one of the other connectors into DF1: (DS1). The third connector should go on the mother board. Then you will have to set the following jumpers on the mother board:

A3000[T]  DF1:          J351 must be shorted between pins 1-2.

A4000     DF1: 880K     J351 must be closed

          DF1: 1.76M    J351 must be open

          (No internal floppy) J351 must be open
Q. How can I use an A3640 (040) processor board in an A3000?

A. The board is a direct replacement for the A3630 processor board. For more information see the guide to using the A3640 in an A3000.

Q. I have an internal SCSI CDROM drive working, except for audio out, in my A2000. I've got the same drive in an A4000, which has an audio input on its motherboard. Is there an audio input on the A2000's motherboard? If not how can I use the CDROM drive's audio output?

A. There is no audio input on the A2000's motherboard. You could possibly solder the wires from the CDROM to the PHONO sockets. You might need a resistor in between (possibly variable?). Apparently there is such an input on the A2000 mother board, somewhere on the internal serial connector, CN304.

Q. How can I upgrade the two 8 Bit ISA slots in my A2000 to 16 Bit?

A. You just need to add the missing connectors (16 Bit extensions) to the mother board.

Q. How can I add an external floppy drive to my A4000T?

A. As this Amiga has no external floppy drive port, it is officially impossible to add an external drive. There is however a modification that can be made to the floppy controller module to give an DB23 external floppy drive port.

Beige Wedge Amigas

Q. How do I upgrade my A500 to 1 Meg CHIP RAM and and the Super Denise?

A. The method required depends on the mother board revision. Full instructions on these two modifications and others are available as Trouble.txt On the Aminet. The 1 Meg CHIP Agnus (8372A) must be in place, but not necessarily in 1 Meg mode for you to be able to use the Super Denise (8373).

Q. Can I use an A500 power supply with my A1200?

A. Yes. The connectors and voltages match perfectly. The higher watt rating should help to solve some power problems and will not do any damage to you A1200. Make sure you use the heavier type (about the weight of a brick), however as the lighter (the weight of a tin can) will not make much difference for solving power supply problems.

Q. How can I disable the RAM on my A501?

A. The EXRAM line will need to be cut. A switch can then be connected to toggle RAM on/off by reconnecting this line. You'll be able to find the necessary pinout information in your A500 manual.

Q. I have a ESCOM AT A1200. Some disk-only games and demos refuse to work, but work perfectly on other, older A1200s. What's going on?

A. The new A1200s had a HD floppy drive set by jumpers as a DD drive. This has caused problems with custom disk loading routines. There is a hardware fix available called A1200FDfix.lha on the Aminet.

Q. What causes the conflicts between PCMCIA cards and A1200 RAM boards?

A. The 68ec020 used in the A1200 can only address 8 Megs of FAST RAM. The PCMCIA slot uses 4 Megs of this address range whether you're using a PCMCIA RAM card or not. This means that only 4 Megs of addressing space is available for a trapdoor RAM boards. Newer accelerators will solve this problem as 68030 has its own larger address range. Some older accelerators use 4 Meg of the 68ec020's addressing range so the same problems will occur.

Q. I want to use an external keyboard with my Amiga. How can I make a suitable adaptor?

A. The following shows the pin outs for all the Amiga's external keyboards:

Pin   A1000   A2/3000   CD32   A4000

 1    +5V     KCLK      DATA   I/O

 2    CLOCK   KDAT      TxD    n/c

 3    DATA    NC        GND    Ground

 4    GND     GND       +5V    +5VDC (100mA)

 5            +5V       CLOCK  Clock

 6                      RxD    n/c

A1000 is RJ12 jack.

A2000/3000 is a 5-pin DIN female.

CD32 is a 6-pin miniDIN female.

A4000 is a 6-pin miniDIN female.
You will have to match up the signals above with the connector on your Amiga's mother board. If you're adding an A2000 keyboard to an A500 (the keyboard interfaces are almost identical) you will need to add a transistor at 2N3904 if you want CTRL+Amiga+Amiga resets to work. Please note that external keyboards don't have LEDs for Power and Disk activity.

PC AT keyboard adaptors are available for the A1200. This is probably the best option. For more information see the hard/hack directory on the Aminet:

Q. How can I upgrade my REV 3, 5, 6a, 7 A500 to OS 2.x +?

A. The installation of the new ROM depends on the mother board revision. For the REV 6a and 7 (A500+) boards the ROM
can just be placed directly into the socket, located to the left of the 68000 CPU. The REV 7 (A500+) has a 42 Pin socket and the ROM has 40 so check that the ROM isn't placed in the top two points, as per the diagram:


  -|     |-<------Don't put any of the ROM's pins in hese two holes. 

1 -+--_--+- 40

2 -|     |- 39

  -| ROM |-

However, if you have a REV 3 or 5 pins 1 and 31 must be connected. For more details see here

Q. What are the Pin outs for the A500/A1200 PSU?

A. Looking into the plug

 __  __

|3 \/4 |  Pin 1 +5v 4.5A          Pin 4 Signal ground

|  5   |  Pin 2 shield ground     Pin 5 -12v .1A

|2___1_|  Pin 3 12v 1A

Q. What are the pinouts for the A1200's LED connector?
From left to right,

Pin 1   (Black Wire !)   Supply to Power LED

Pin 2   (Red Wire)   Supply to Floppy LED

Pin 3   (Orange Wire)   Supply to HD LED

Pin 4   Not used

Pin 5   (Green Wire !)   0v common for the LED
If you are going to connect these wires to a tower case's LEDs you will need to connect a resistor (possibly 330 Ohms) in series with each of the supply wires to stop the leds blowing.

Q. What are the pinouts for the A1200 mouse port (daughter board)?




                                1  2  3  4  5

             . . 5              .  .  .  .  .  

         9   . . 4               .  .  .  .

         8   . . 3               6  7  8  9

         7   . . 2

         6   . . 1

These match up pin for pin.

CDTV and CD32

Q. I have an A570 CDROM drive...

A. See the A570 FAQ for all questions related to this CDROM drive.

Q. What are the pin outs for the CD32 power port?

                                         View straight on. 4 pin din.

             _ _

 1 +5V     .' V `.

 2 +12V    |1   2|

 3 Ground  `.3 4.'

 4 Unknown  `---' Shield

 Put a ground jumper from pin 3 to the shield.
Q. What are the pin outs for the CD32 AUX port? How can this be used as a serial port? What problems are there when using this as a serial port?
View straight on. 6 pin mini-din.

    Female type. Combined kboard/serial.


 1  I / O  Keyboard data          _ _

 2  I / O Serial transmit/TXD   .' V `.

 3  Ground                     / 6   5 \

 4  +5V DC                    |4   O  3 |

 5 (I)/ O  Keyboard clock     `-. 2 1 .-'

 6  I   Serial receive/RXD      `-----' Shield

To use this port as a serial port, see CD32_Amiga11.lha and CD32Link.lha
  • There are no RTS/CTS pins for high speed modems.
  • The serial pins are at 0/5V, if the computer you're connecting it to has a different voltage (eg. the Amiga serial port's pins are at +/-12V) then you need a level converter between the two.
  • The serial pins may not be properly buffered to use safely with some external devices. You could damage your CD32 if you try to hook them up without an external buffer. A diagram of a buffer is given in the posting mentioned above.
Q. How do I stop my CDTV/CD32 resetting when I take the CD-ROM out?

A. If you boot from CD-ROM, the CD32 resets when the lid is opened. You can either run a program such as NoReset that disables this or boot from another device, such as RAD, floppy, or hard drive.

Q. How can I use non-autobooting CDROMs, such as Aminet 4, with my CD32 linked to my Amiga?

A. You can boot from a CDROM which disables the RESET function, using NoReset. Due to a (yet another) strange oddity in the Commodore 3.1 CDFileSystem, you can only use CD-ROMs with a lower or equal ISO revision than the disc you booted from (this is irrelevant to SX-1 users, for they are likely to boot from hard drive or floppy). The Aminet 4 CD and the GoldFish CD-ROM set by Fred Fish are two examples of discs that use a higher revision than the Weird Science Network CD. This means that you can't access the discs properly or at all.

Alternatively, you can set up a RAD disk, which will survive reset and boot from that. Instructions for doing this are found on the Aminet as Aminet4_CD32.txt.

Q. How can I upgrade my CDTV?

A. Expansion devices have always been limited. However most upgrades for the A500, which sit in the 68000 socket can simply plugged in. Also a 2 Meg Agnus daughter board can be added to give an extra Meg of CHIP RAM. For more information, including how to upgrade to OS 2.x see the CDTV Technical Page.

Zorro Cards and other interfaces

Q. Which IO card is better, the GVP IO Extender or the BSC Multiface III?

A. There have been several reviews and comparisons in recent Amiga magazines. The IO Extender has better (faster) Serial ports, but the MultiFace III has a far better Parallel port (Scanner and network support) and adequate Serial ports. The best thing to do is to check the comp.sys.amiga.reviews archive for the reviews of the MultiFace III and IO Extender.

Q. I have an A2000 with a GVP SCSI Series II hard card with 8 Megs of RAM on board. If I add a Picasso II, will there be any problems?

A. Yes. The Picasso II has 2 Megs of its own RAM which it maps into the Zorro II address range. This RAM will cause an addressing conflict with the 8 Megs you already have. The solution is to drop the 8 Megs down to 6, by changing the jumper settings (if this amount is possible) and the Amiga's AutoConfig will sort out the rest of the Zorro II addressing.

Q. What are the pin outs for the 10 way second serial connector on the GVP IO Extender?

A. This is the pin out for the 10 way header on the board.

           ­­­­ ­­­­ 

   CN4 :  |5 4 3 2 1| 

          |- 9 8 7 6|  if you use a ribbon cable, it will be correct almost

           ¯¯¯¯¯¯¯¯¯   automatically.

 1 = DCD    6 = DSR

 2 = RxD    7 = RTS

 3 = TxD    8 = CTS

 4 = DTR    9 = RI

 5 = GND
Q. What are the DIP switch / Jumper settings for the A590?

A. See http://www.nationalamiga.com/t-A590.html.

Q. I have experienced strange problems when using a MultiFace III IO card and a FastLane Z3 SCSI card. My Amiga 4000 doesn't boot, however when either of these cards is removed the system works perfectly. How can I fix this so that both cards can be used simultaneously?

A. When using the MultiFace III and the FastLane in the A4000, the FastLane should be in a lower slot (closer to the motherboard) than the MFC III. If the Multiface is lower than the FastLane, using the software PIT0: device will cause the system to lock up.


Q. Why were the original Amigas so slow?
A. One reason is that the 7.14 MHz clock speed is timed to the PAL/NTSC video rates. This was done to give the Amiga such good video capabilities. In the early days, people used to add 16 MHz 68000 processors for extra speed. They weren't much faster because everything in the Amiga was locked to 7.14 MHz (1/4 of the PAL rate). Even in newer Amigas the custom/IO chips still run at this speed.

Q. I have an A500 with a 030 25 MHz accelerator with no 32 Bit RAM. I find this very slow, compared to 25 MHz A3000s If I upgrade to an A1200, should I buy a 68060 50 MHz accelerator?

A. You must remember that accelerators need 32 Bit RAM for a full speed increase. The A500 is still a 16 Bit machine, so any operations external to the accelerator will be slow. For this reason it is important to reduce such external operations by fitting RAM to an accelerator and if possible SCSI hard drives as well. The A3000 has 32 Bit architecture, RAM and the Zorro III bus. This is why it is so much faster. For example a test render with Cinema 4D on a A500+ with 4 Megs of FAST RAM took 12 minutes. The same render on the same machine with a 40 MHz 030 took 8 minutes. However the same render on an A2000 with an 40 MHz 040 and 8 Megs of 32 Bit FAST RAM took less than 30 seconds. The final two tests show the speed differences between two processors with the same clock speed.

An accelerated A500 without 32 Bit RAM runs ~1.7 times faster than a stock A500. A stock A1200 is supposed to be 4 times faster than a stock A500, even though the it only has twice the clock speed. The extra speed comes from the 32 Bit CHIP RAM and architecture. So an 030 or 040 might be a better solution, giving much better performance than your current system, at a lower price than the 060.

Q. What's the difference btween the 68ec030 and the 68030?
A. The ec version is supposed to have a smaller memory addressing range and can't be clocked as fast as a full 68030 can be. The ec version also lacks a MMU. This means that virtual memory, kickstart remapping, enforcer style debugging tools and UNIX systems (such as Linux and NetBSD) can't be used.


Q. What is the "Expansion" drawer used for?
A. Some Zorro II/III cards without ROMs have drivers in the "Expansion" drawer, such as the Multiface III and IO Extender. Under OS 1.2, non-autobooting hard disks had drivers here as well. With 1.3 and auto-boot support, these were dropped. Otherwise it is rarely used.

Q. In the L: directory on my hard drive, there is a file called 'FastFileSystem'. I can't find it on any of my Workbench disks. Where has it come from?
A. This was part of OS 1.3. Now it is stored in ROM, so can be deleted. It was most likely left over from upgrading or added by some installation software.

Q. I'm left handed and therefore find difficulty using mice. Apart from software based hacks, how can I modify my Amiga mouse to swap its buttons round?
A. You can swap the mouse button wire over, so that the button pressed with your index finger will have left function. According to the A500 User Manual, it's the wires from pins 5 and 6 which carry the buttons' signals and therefore need to be swapped round.

Q. What do the various boot up colour screens mean? What do the keyboard blinks actually mean? What diagnostics does the Amiga run through at boot up time?

A.The failure colors are:

 YELLOW  680x0 Exception is taken before the real Exec exception

   handler is installed.

 GREEN  Chip memory fails.  This can be a real chip memory 

   failure, or a problem writing to the CIA chip that 

   controls the ROM overlay.

 RED  ROM checksum failure.  

 BLUE  Chip failure -- something's wrong with Agnus, Denise,

   or Paula.
The keyboard self test results are:
One blink  The keyboard ROM check failed

Two blinks The keyboard RAM check failed

Three blinks The watchdog timer test failed

Four blinks A short exists between two row lines or one of the

               seven special control keys
Read errormessages.txt for a more detailed description.

Floppy and Hard disks

Q. How can I add a HD floppy drive?
A. If you have a desk top A4000 or a late A3000[T] you already have a HD floppy. There are some hacks on the Aminet to allow this on other machines. However these were special half speed devices as the Amiga's disk IO hardware wasn't designed to support High Density disks. The best option is the power computing XL drive. If you have an A4000T, with no external disk port, you will have to get the internal version. A new half speed High Density floppy drive is now available in internal and external form. If you have an A1200 a device called the Cat Weasel allows you to connect a full speed PC HD floppy drive. It is however better suited to A1200Ts.

Q. After replacing my internal floppy drive, all my floppy drives failed to work and info reports that I've got DF0: - DF3: installed when I've only got and internal and one external drive. What's going on?

A. The internal floppy drive cable may have been put in the wrong way round.

Q. Why can't I use the parallel version of the Zip Drive?

A. Firstly the drivers aren't available. The reason for this is that the Amiga's parallel port doesn't have the speed to drive such devices. See the complete comparison of the Amiga's and PC cones' parallel ports for more reasons as to why use of these drives is impossible.

Q. How can I persuade the OS that my second floppy drive is DF0: as my internal drive is damaged?

A. You could use a tool like Degrader, which allows floppy drives to be remapped to others as well as disabled. Otherwise add the following to your S:User-Startup:

; Disable DF0: and map DF1: in its place

Assign Dismount DF0:

Assign DF0: DF1:

This will fool any CLI commands, so you can CD to DF0: and DF1:, reaching the same destination drive. Even DMS works with this system. However most games and demos will use custom / non OS-legal floppy addressing and will fail.

Q. How can Win 95 floppy disks with long file name support be read?

A. Such floppies and hard disks can be read only using Win95 FS. This filesystem does not support writing or reading from sub-directories.


Q. How do you use HDToolBox with third party SCSI cards?

A. In tooltypes, add: SCSI_DEVICE="xxxscsi.device", where xxx.scsi.device is the name of you SCSI controller's device driver. For example gvpscsi.device, omniscsi.device, 2060scsi.device. This will be case-sensitive. A full list of device drivers can be found on National Amiga's WWW site

Q. I use AFS on my hard disks with a GVP SCSI controller. Are there any known problems?

A. Yes. Don't use the GVP Prep tools. They are incompatible with AFS and will damage the ridged disk block (RDB), losing all your data. Use HDToolBox instead.

Q. I have an A4000 (IDE bus) and a A4091 SCSI card. Both use scsi.device. How can I access the IDE hard drives and the A4091's drives with HDToolBox?

A. The A4091 (or A2091 for that matter) can be addressed as '2nd.scsi.device'. The IDE interface will remain scsi.device. When updating software, remember that device drivers are case-sensitive of the Amiga.

Q. What are the problems with the WD33C93A SCSI controller chip? How can they be solved?

A. This chip used in the A3000, A2091 and GVP SCSI controllers can cause lock ups and random checksum errors when one than one SCSI device is used. There is a replacement chip, which is deficult to locate. Also the GURU ROM seems to fix some of these problems.

Q. I have a Surf Squirrel and SCSI board on my accelerator. At boot up, the machine hangs for sometime and then boots normally. How can I speed this process up?

A. If you have any removable devices such as a ZIP drive, check that there is no disk in that drive as if one is found as UNIT 1, for example, all other units will be searched. This can take a very long time especially if all LUNs are checked as well as SCSI UNITs. On the device with the highest UNIT ID you can set the last-disk flag which will disable further searching. Some controllers, such as GVP Series II and Phase 5 accelerator SCSI cards prefer devices to be place in numerical order.

Q. I have a A2090[A] SCSI controller...

A. See the A2090 FAQ for all questions relating to this SCSI controller


Q. What software is needed to read from a SCSI CDROM drive?

A. You will basically need a CDROM Filing System. One is included with OS3.1, but it's not very good. The best at present is AmiCDFS, available on the Aminet. Filing Systems consist of several different parts:

  • Handler, this is placed in the L: directory
  • DOSDriver, this contains information on your CDROM drive. You need to add the name of your SCSI driver and the CDROM drive's UNIT ID.
Each CDROM Filing System has various extras that also need to be set up but these are documentated in the Filing Systems' archives.

Video Hardware

Q. I'm using a Microvitec monitor with my A1200 and suffer from flickering horizontal lines and vertical bars with ghosting text. How can I stop this happening?

A. This is a hardware flaw in the AGA chip set, which causes vertical strips on screens using higher bandwidth screenmodes such as MultiScan and DBLPAL. To fix this you need to add a resistor to your monitor adaptor. Details of this modification can be found in AGABandingFix.txt.

Q. How can I surpress interference with the A520 TV Modulator?

A. Solder a wire from the hole in the PCB, next to the crystal to the top of the crystal.

Q. Can I use the A520 modulator with the A1000 or A4000?

A. Yes, it plugs straight into the RGB port.


Q. ShapeShifter won't work with my new 060. Why?

A. This is a problem with the Mac ROMs and the 060. It is rumoured that Apple have done this to stop Amigas running Mac software better than real Macs can :-)

Q. Why won't Shapeshifter (PrepareEmul) work with my accelerated A1200/A2000 (with Blizzard 2040?)?

Try MacMem, use PrepareEmul A1200 (this does the same as MacMem) or see 'Here's What I did to get SS to work on an Accelerated A1200' by Jeff Harris

Q. How can I use the PC ISA slots in my Big Box Amiga?

A. These slots can only be used with a Bridge Board, either the full emulator or the Golden Gate, which enables you to use cheap PC hardware from the Amiga side only. Use of such a card, in a shared PC ISA/Zorro will bridge this PC and Zorro interfaces, allowing PC cards to be used. However these slots are powered, so PC "Fan" cooler cards can be used with out a Bridge Board.

Q. Can a PS/2 keyboard (or whatever) be used in the PS/2 plug on the back of the 386 Bridge Board?

A. It's not a keyboard jack. It was intended to bean automatic monitor switcher, if you had a GFX card in an ISA slot. Officially, people say that the switcher circuit was never completed, others say that you can access the pins of the port with a program and do something.


Latest updates to the Amiga History Guide. (more)

· Amiga Hardware
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· AmigaOS 4.0
· Amiga University
· Commodore Retrobits
· Dave Haynie archive
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