NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/sys/amiga/hardware-part1/2701

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From: [e-mail] (Warren Block)
Newsgroups: comp.sys.amiga.hardware
Subject: A1200 Hardware FAQ
Date: 27 Jan 1996 16:53:08 GMT
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A1200 Hardware Frequently Asked Questions
             Version 1.6
-----------------------------------------
   Copyright (C) 1995 by Warren Block.


Distribution
------------

This document is FreeWare. It has been copyrighted to assure its availability
to everyone. Fred Fish and the Aminet are explicitly allowed to include this
document in CD-ROM or floppy compilations; others should ask first.


Disclaimer
----------

The information contained herein is a crock. It's full of dangerous errors,
omissions, and outright lies, and is not guaranteed to do anything other than
take up disk space. Not for internal use. Keep out of reach of demo coders.


Introduction
------------

After putting together a much fancier document for the A4000 (the Amiga 4000
Hardware Guide), it was suggested that something similar was needed for the
A1200. Additionally, I kept seeing the same questions asked over and over in
comp.sys.amiga.hardware, and it seemed like a FAQ might help both those
asking and answering the questions. Maybe it'll just change all the answers
to say "Read the FAQ, you moron." Nah. Amiga people are more polite than
that. They'd say "PLEASE read the FAQ, you moron."


Introductory Questions
----------------------

Q. I have a problem with my A1200. Can I email or call you for help?
A. I'd rather you ask any questions that aren't answered here in a public
   forum in comp.sys.amiga. That way, you can draw on more experience than
   just my own (which is admittedly somewhat limited with the A1200), and the
   answers can benefit others with similar problems.

Q. Hey! You left out many details on some of these topics.
A. That was intentional; some of these answers have been simplified, both to
   keep this document relatively short, and to avoid confusing the issues.
   Please remember that this is an introductory document, and not a technical
   reference guide, and is intended merely to answer the most common
   questions. So there. Nyah.

Q. Hey, FAQ boy, you screwed up, and some of this information is wrong, or
   you just didn't include something that was completely obvious! Can I send
   you email with the correct information?
A. Yes, please do. I am:

   Warren Block
   602 St. James
   Rapid City  SD  57701
   [phone] Voice

   [e-mail]

Thank you for your interest, and good luck with your A1200!


------------------------------------------------------------------------------


Power Supply
------------

Q. I want to build a "super power supply" for my A1200. What are the pinouts
   of the power supply connector?
A. Look on the power supply itself, where the pinouts are specified.

Q. Can I use an Amiga 500 or Amiga 600 power supply with my A1200?
A. Yes. The connectors and voltages match perfectly.

Q. What about the higher watt rating of the A500 supply? Won't all that extra
   power melt and/or blow up my A1200?
A. No. The watt rating of a power supply only describes the absolute maximum
   amount of power it can supply. The A1200 will only draw as much of this as
   it needs to operate.


Floppy Drives
-------------

Q. Can I use an IBM high density drive on an A1200?
A. Not easily, simply, or reliably.  There are some hacks that allow this,
   but, as of this writing, they all still have problems, and can be
   considered experimental. If you're determined to try, there are several
   plans in the hard/hack section on Aminet.

Q. Can I read and write Amiga diskettes on a PC clone?
A. No. The floppy controller hardware on the clones is incapable of reading
   or writing the Amiga disk format. To transfer files on disk between a PC
   clone and an A1200, use 3.5-inch double-density floppies formatted in the
   720K MS-DOS format. The A1200 can read and write these using CrossDOS
   (included with AmigaDOS 3.0).

Q. Can I use high-density floppies with the A1200's normal disk drive?
A. Not reliably! Writing high-density disks with a double-density drive will
   result in erratic operation of those disks. They may work fine for hours,
   days, or weeks, only to fail when you need them most. The double-density
   drives just can't write reliably to high-density disks. Use double-density
   disks with Amiga double-density (880K) drives, like the one built into the
   A1200, or get an external or internal high-density Amiga drive.


Hard Drives
-----------

Q. Why doesn't my A1200 boot off the hard drive when I first turn it on?
A. Many hard drives don't spin up fast enough to be ready when the A1200
   is ready to boot. If you can reset the A1200 after it comes up with the
   purple "insert floppy" screen and it will then boot from the hard drive,
   this is the case. The easiest solution is to just live with it and reset
   the machine when you first turn it on. If this really bothers you, you
   could replace the drive with one that spins up faster.

Q. How hard is it to install a hard drive inside my A1200?
A. It's not hard. You need a few things: a 2.5-inch IDE hard drive (commonly
   used for notebook computers), a short section of special 44-pin ribbon
   cable to fit the drive (this cable is spaced more tightly than normal
   ribbon), and, preferably, the Commodore Install disk. First, you install
   the drive, then use the Install disk to partition it and place the system
   software on it. That's it. The toughest part is obtaining the Install disk
   and the special cable.

Q. Should I low-level format the hard drive?
A. No. On both IDE and SCSI drives, an initial low-level format has been
   performed at the factory. You should never need to low-level format them
   again. After partitioning, you *do* need to "high-level" format a hard
   drive with the AmigaDOS Format command; when used with hard drives, you
   can specify the QUICK keyword with the Format command to speed up this
   high-level formatting immensely.
   (Example: Format drive dh2: name "Sample" quick noicons.)

Q. Can I use a 3.5-inch hard drive inside my A1200?
A. Not without hacking it in there. Physically, it can be made to fit;
   but problems can arise from the extra power consumption of the 3.5-inch
   drives, coupled with the anemic stock power supply of the A1200. Obtaining
   a cable to adapt the 44-pin high-density IDE cable to the 40-pin
   normal-density IDE connector can be difficult, too. Electronically, they
   are compatible. See the hard/hack directory of Aminet for projects.

Q. Can I use an "EIDE" or "Fast ATA" hard drive with the A1200?
A. Yes. These drives are merely refined IDE drives.

Q. Will large-capacity (500M and up) drives work with the A1200?
A. Yes. The 500M capacity "limitation" originates from the PC clones, and is
   only a problem with them. For the Amiga, you can safely go up to a 2G
   (~2000M) hard drive, provided you can find (and afford) one that large in
   a 2.5-inch IDE or EIDE format.

Q. What is MaxTransfer?
A. MaxTransfer is a value (set in HDToolBox) that limits how much data can be
   transferred to or from the hard drive in one "gulp."

Q. Why is MaxTransfer needed? Shouldn't the drive move as much data at one
   time as possible?
A. Yes, it should, but some hard drives have arbitrary limits on how much
   data they can move at one time. On the Amiga, if you have problems
   transferring files of 128K or larger to or from the hard drive, this is a
   likely cause of the problem.

Q. I have have no idea what the MaxTransfer value should be for my drive.
   What value should I use?
A. For unknown drives, the maximum "safe" value is 0x0001FE00. Other drives
   may require 0x0000FFFF or even 0x0000FE00. The sure test is to copy files
   larger than the MaxTransfer value to and from the drive, checking for
   corruption afterwards. IFF pictures work well for this, as corruption is
   easy to see.

Q. What drives are known to need the "safe" MaxTransfer values?
A. As of this writing, some Maxtor drives need the maximum safe MaxTransfer
   value of 0x0001FE00.

Q. What is Mask?
A. Mask is a value (set in HDToolBox) that determines what type of memory
   (Chip or Fast) can be used to buffer data transfers to or from the hard
   drive. Unless you have a good reason to change it, leave it at the default
   setting in HDToolBox.

Q. What 2.5-inch IDE hard drives are known to work with the A1200?
A. Most do, although you may have to adjust the MaxTransfer value (see
   above). I personally dislike the Seagate drives included with many A1200s
   (I consider them the Kraco of hard drives), but they work fine for many
   people. My own Toshiba works fine, although, like many drives, it has the
   "slow spin-up" problem.

Q. When I first power-up my A1200, the hard drive works fine, but after a
   reset the hard drive is no longer recognized. What's wrong?
A. This is a problem with the hardware IDE reset signal. The easy fix is to
   cut pin 1 on the IDE cable (usually the one with the stripe), peel back
   the wires a little, and tape them off, disconnecting the reset signal.


CD-ROM Drives
-------------

Q. What SCSI CD-ROM drives work with the A1200?
A. First you need a SCSI interface, like the Dataflyer SCSI+, the SCSI
   interface built into certain accelerators, or a PCMCIA SCSI card like the
   Squirrel. Some SCSI controllers have trouble with certain drives, but in
   general, the Apple CD300 (which is a Sony drive), Toshiba, and NEC drives
   have been reported to work well with the Amiga. Personally, I can verify
   that the NEC 3Xe works fine with the SCSI+ interface.

Q. Can an IDE CD-ROM drive be used with the built-in IDE of the A1200?
A. Yes, but not easily. Most non-SCSI CD-ROM drives are not IDE, but a
   "sort-of" IDE. Newer drives are EIDE, and these can be made to work on the
   A1200. It requires an ATAPI driver (a demo version of one is available on
   Aminet) and the 44-to-40-pin adapter cable. It is possible to build some
   circuitry to allow attaching an older Mitsumi CD-ROM drive, but the
   availability and status of the driver software is still in question. My
   opinion: SCSI gives you much more for your money, because you can use the
   SCSI bus for other things in addition to CD-ROM drives. Some accelerator
   boards have SCSI ports, offering an all-in-one solution.

Q. What software do I need to access a CD-ROM drive?
A. Frank Munkert's excellent AmiCDROM filesystem, or the one that comes with
   AmigaDOS 3.1. AmiCDROM works extremely well on both ISO 9660 and HFS
   (Macintosh) CD-ROM discs, and it's free. Look for it on
   Aminet: disk/cdrom/AmiCDROM-1.15.lha.

Q. I need more information on CD-ROM disks, drives, and interfaces,
   especially as they relate to the Amiga. Where can I look?
A. There is an excellent overview of the subject by Joachim E. Deu▀en on
   Aminet. Look at the file docs/help/CDROM20.lha.


Processors
----------

Q. What is the 68EC020 processor that comes inside the A1200?
A. It is an inexpensive version of the 68020, in a Plastic Leaded Chip
   Carrier (PLCC) package. The only electronic difference between this
   processor and the 68020 is that the EC version only brings out signals
   for 24-bit addressing. Internally, it is fully 32-bit.

Q. What's the difference between the 68EC030 and 68030 processors that come
   with accelerator boards?
A. The two are physically the same, with the difference being that a 68030
   has a functional Memory Management Unit built into it, which the EC
   ("Embedded Controller") version lacks. The MMU is useful for programmers
   (for debugging purposes), allows running Unix systems like NetBSD, and
   also can be used to remap Kickstart code, allowing the system to run
   faster (in some cases--this depends on the individual system, accelerator
   board, and memory).

Q. Are there any 68040 accelerators for the A1200?
A. Not at this time. It is probably impractical to build a 68040 accelerator
   for the A1200, due to the amount of heat the 68040 generates and the
   limited space inside the A1200.

Q. Are there any 68060 accelerators for the A1200?
A. Since the 68060 uses less power and generates less heat than the 68040, it
   is a logical upgrade to an A1200. Several 68060 accelerators for the A1200
   have been announced, and should be available in the last quarter
   of 1995 or the first quarter of 1996.

Q. Can I replace the 68EC020 that comes with the A1200 with a full 68020?
A. Not directly, no. The 68EC020 is soldered onto the A1200 motherboard, and
   even if it weren't, the 68020 differs physically from it. The best way to
   perform this upgrade is with one of the many inexpensive accelerator
   boards.

Q. Can I replace a 68EC030 with a 68030 with an MMU?
A. Yes, as long as they're physically the same. Some 68030s are Pin Grid
   Array (PGA), and some are Plastic Leaded Chip Carrier (PLCC). With the PGA
   type, you can carefully and gently pry the old chip out of the socket and
   then replace it with the new one. Some PLCC chips may be soldered down,
   some may be in sockets. If it's in a socket, yes, you can replace it, but
   you should get the proper removal tool to avoid breaking the socket.


Memory
------

Q. What do I need to expand the memory of my A1200?
A. You'll need either a RAM board or an accelerator board, either of which
   will fit into the trap-door expansion port on the bottom of the A1200, and
   will have sockets for memory expansion. Please note that some expansion
   boards made by GVP use custom SIMM modules, which are hard to find and
   much more expensive than standard 72-pin SIMMs.

Q. My accelerator or RAM board has one or more 72-pin sockets for memory
   SIMMs. Can I use 72-pin SIMMs meant for PC clones?
A. Yes. Read on for more details.

Q. Some 72-pin SIMMs are 36-bit and some are 32-bit. Is this related to
   "parity," and which do I need to use with the A1200?
A. PC clones use extra "parity" bits for double-checking memory. On the
   A1200, these extra bits will simply be ignored, causing no problems. The
   extra four bits on the 36-bit wide SIMMs are these parity bits. The 32-bit
   wide SIMMs are usually meant for use on the Macintosh, which, like the
   Amiga, don't use parity. Summing up: 36- or 32-bit wide SIMMs--which is
   just another way of saying "with or without parity bits"--will work for
   accelerators or RAM expansion boards with 72-pin SIMM sockets.

Q. I've seen SIMMs with speed ratings of 60, 70, and 80 ns. What does this
   mean, and which do I need?
A. These numbers rate the speed at which the SIMM can be reliably operated. A
   60 ns SIMM is the fastest currently available at reasonable prices. To
   keep a processor running at its fastest rate, the memory needs to be able
   to keep up with it; the speed of your processor determines the minimum
   memory speed needed. For an A1200 with just a RAM expansion board, 80 ns
   SIMMs are fast enough. With an accelerator, it depends on how fast the
   processor is going, so you'll need to check the manual. (Note: many boards
   let you use slower SIMMs with them by enabling a "wait state," which
   forces the processor to slow down to the SIMM's speed, and allows you to
   use cheaper SIMMs. For instance, an accelator may say that it requires 70
   ns SIMMs to run at "zero wait states," but will operate with an 80 ns SIMM
   (slower) if you set a jumper to enable a wait state.)

Q. If I get faster SIMMs than I need, will it make the computer run faster?
A. No. This is a common misconception. The processor determines how fast the
   memory needs to be, and will not run any faster even if the memory is
   capable of it. For instance, if your accelerator needs a 70 ns SIMM, and
   you use a 60 ns SIMM, it will not run any faster than it would with a 70
   ns SIMM. (It may be a good idea to buy faster RAM than you need, though,
   since you could then use it with a faster processor in the future.)


Monitors
--------

Q. I have a VGA or SVGA monitor from a PC clone. Can I use it with the A1200?
A. Maybe. The "double" video modes of the A1200's AGA chipset provide video
   frequencies of 23 kHz and up, and will work with many VGA monitors.
   However, true PC clone-type VGA operates at a frequency of 31.5 kHz, and
   some monitors won't operate at frequencies much lower than that. The "VGA
   Only" monitor driver may be used to raise the A1200 output frequencies,
   making them high enough to be recognized by some monitors. You should
   certainly try any VGA monitor before you buy it, though, just to be sure.
   (Note: many games and some system software operate only at 15.75 kHz. For
   instance, the configuration screen you get by holding down the mouse
   buttons during a reset only displays at 15.75 kHz, and will not be visible
   with a VGA-type monitor.)

Q. What specifications does a multisync monitor need to work with the A1200?
A. Ideally, you need it to have a sync range from 15 kHz to 31.5 kHz or
   higher. Digital presets are helpful because they allow you to set screen
   size and centering for all the different screen modes.

Q. Where can I get an adapter to go from the A1200's DB23 video port to the
   goofy high-density HDD15 standard VGA connector that looks like a DB9?
A. The adaptor that comes with an A4000 can be used, or you can get a wiring
   diagram from Aminet: hard/hack/ami2vga.lha. Alternatively, you could have
   Redmond Cable build one for you (call them at 206-882-2009).

Q. Can I use a CGA monitor with an A1200?
A. Yes, but it won't work particularly well. CGA is digital RGB, so it can
   only generate 16 predefined colors. If it's the only monitor you have, you
   can probably live with it, but I would personally recommend even a
   composite video monitor instead (the old 1702 would work well for this).

Q. What Commodore monitor should I buy for use with the A1200?
A. My opinion: Don't buy any Commodore monitor. There are several monitors
   like the Microvitec 1438 and 1440 that are marketed specifically use with
   the Amiga, and there are general-purpose VGA-type monitors that also work
   well. In most cases, these monitors are less expensive, better made, and
   more reliable than those that were sold by Commodore (which were OEMed
   from monitor manufacturers anyway). If you're looking for something
   inexpensive that will work with all the frequencies and output modes of
   the A1200, see if you can locate a used Mitsubishi DiamonScan (AUM 1381A).
   These monitors are quite cheap now, and besides handling all the RGB
   output of the A1200, also have a composite video input. If you're buying
   something new, I recommend a monitor with digital presets, which makes
   screen adjustments much easier and eliminates the need to fiddle with
   knobs every time you change screen modes (the Microvitec 1440 mentioned
   above is reported to have digital presets).


Other Questions
---------------

Q. I don't like to shut off the A1200 to connect and disconnect joysticks,
   modems, sound samplers, and printers. Can I damage the A1200 by changing
   these connections with the power on?
A. Yes. Remember that the A1200 design uses chips that are almost all surface-
   mount, soldered directly to the circuit board. This makes it very
   reliable, but when you expose it to dangerous behavior (changing
   connections with power applied), you risk damaging chips that are very
   difficult to replace and extremely difficult to obtain. Before you switch
   cables, make sure that power is off to the entire system, including the
   peripheral you are connecting or disconnecting.

Q. Is there a way to get a battery-backed clock into the A1200 without buying
   an expensive expansion board?
A. Yes. There is a header on the A1200 motherboard specifically for adding
   one of these inexpensive clock boards, which usually cost less than $30.
   However, a RAM expansion board with a clock is usually only about double
   that, and gives you the ability to add 32-bit expansion memory later,
   which will approximately double the operating speed of the A1200.

Q. Can I modify the A1200 to have a remote keyboard?
A. Yes, if you're really motivated. There is a file on doing this in the
   hard/hack section of Aminet. It is non-trivial.

Q. Can I remount my A1200 in a PC tower case?
A. Yes, although it'll be a lot of work, and no warranties. See the hard/hack
   section of Aminet.

Q. Can the A1200 be upgraded to AmigaOS 3.1?
A. Yes. The operating system ROMs are socketed, and several places are now
   selling versions of 3.1 that are specifically made for the A1200.

Q. Is there an adapter box that lets me use Zorro boards on the A1200?
A. At present, I have information on one expansion box for the A1200. It is
   made by Ramiga (UK phone [phone]). The box is called the Ramiga Z5,
   has three 5.25-inch drive bays, five 3.5-inch drive bays, five Zorro-2
   slots, four PC slots, and a 230 watt power supply (thanks to Chris
   Appleton for this information). List price is 499 UK pounds. Details are
   still scarce at present. Experience with adapters of this type for earlier
   Amigas suggests that they may only work with certain boards, or have
   difficulties with certain operations.

Q. Can I use a Video Toaster with the A1200?
A. No. The Toaster requires a video slot. There are video digitizers and
   genlocks available specifically for the A1200, though.

Q. Is there a Mac emulator for the A1200?
A. There is a shareware software Macintosh emulator called ShapeShifter (on
   Aminet, in the misc/emu directory). The catch is that you need to find a
   512K or 1M ROM from a recent Mac to get it to run. An A1200 version of the
   Emplant Mac emulator was once announced, but was never released.

Q. Is there an internal jumper on the A1200 to set it to default to PAL or
   NTSC video?
A. No, but if you're really motivated, you can rig this up. My thanks to
   Tetsuo Oda and Byron Montgomerie, who provided the information that
   connecting pin 41 of the Alice custom chip to ground causes the A1200 to
   default to NTSC, while pulling this pin high (disconnecting it from the
   motherboard and connecting it to +5V through a 4.7k resistor) will make
   the default power-up state PAL. I would point out that making a
   modification like this on a surface-mount chip is difficult at best, and
   you may end up in an expensive motherboard replacement, or, at worst, a
   dead A1200 with no replacement motherboard available.


Conclusion
----------

Will Paula meet the blitter of her dreams? Will Akiko ever get together with
Fat Agnus? And what is the mysterious PCMCIA Corporation planning in their
corporate headquarters at 68030 DMA Drive? Tune in next week...

--
.----------------------------------------------------------------.
|  Warren R. Block    *  New EMail Address: [e-mail]  |
|  Rapid City SD USA  *  Brought to you in majestic INEMASCOP!   |
`----------------------------------------------------------------'