- amiga history guide Supporting Amiga and compatibles since 1997 -
-
-
- banners - disclaimer - faq
 
- - -
- -     -
-
recent updates
amiga history
features
amiga models
magazines
technical
interviews
internet links
downloads

 

-

© 1997-2006
Gareth Knight
All Rights reserved

-

 
-
I-r-r-i-t-a-t-i-n-g

Frequently Asked Questions

Copyright © 1998 Warren Block (wblock@rapidnet.com)

Magic Beans

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. Please do not modify and distribute this file without permission.

Q. What is the IFAQ?

A. Irritating questions are those that are asked over and over. They can be answered a thousand times, and the next day somebody will ask again. While asking questions is a time-proven way to gather information, many long-time Usenet users get sick of answering the same old thing. So here's this FAQ. Odds are pretty good that you'll get this instead of a custom- written answer; don't take this personally. In fact, the next time you see somebody ask that question, you can do the same thing. (Please realize that in many cases, I have intentionally left out some detail to avoid clouding the issues.)

Q. I feel so guilty. What can I do to atone for having asked some of these irritating questions myself?

A. When someone else asks, help answer them. Eventually the crippling guilt will fade. Probably.

Q. You seem to write a lot of these FAQ things. Why?

A. Because so often a question is asked, and never gets answered, or worse, gets a wrong answer. That really bugs me. It's a big waste of time; for instance, look at how much time has been wasted in discussions of MaxTransfer, and even now it's still widely misunderstood.

It would be nice if I could do this type of technical writing and get paid for it. Everyone is welcome to contact me regarding that type of thing.

 

Contents

 

Really Irritating Questions

Q. Could my MaxTransfer rate be too high? What should it be?

A. My initial reaction to questions about MaxTransfer is usually a shout of "Bite me! Arrrrrggggh!" This usually frightens off everyone except the really serious. MaxTransfer has almost nothing to do with transfer rates. It sets the Maximum Transfer SIZE, and is needed to deal with many IDE drives that are built assuming that they'll be used only in rock-stupid PC hardware. If a transfer larger than this size (usually 128K) is requested, the drive will garble some data. Setting MaxTransfer to 0x1FE00 for each partition will force large transfers to be broken into 128K sections, avoiding the IDE bug. Very old drives might need a setting of 0xFE00. MaxTransfer is almost never an issue with SCSI drives, and you can usually set it to arbitrarily large values (HDToolBox defaults to 0x7FFFFFFF). For more details on MaxTransfer, see the >A1200 Hardware FAQ.

Q. What should I do to people who keep associating MaxTransfer with speed?

A. Make up bizarre explanations. See if you can get them to try every value from 0 to 256K in increments of four bytes. Or you can just have them try DiskSpeed with various values, but that's not nearly as much fun.

Q. I really, really, really want to hook up my parallel Zip drive to my Amiga parallel port. Is it possible?

A. Yes, see the hard/hack/ppazip.lha file on Aminet. Now go away.

Q. Will other PC parallel-port devices work on the Amiga?

A. Usually not. Except for printers, PC parallel-port devices like tape drives, Ethernet adapters, digitizers, and storage devices are built for the quirks of the PC parallel port, and won't work on the Amiga. There are two problems: some of the lines on the Amiga parallel port are not software-controllable, and most of the manufacturers of PC parallel-port devices will not reveal details of how to program these devices.

If you want to share a Zip or EZ drive between an Amiga and a PC, get the SCSI version of the drive and an inexpensive SCSI adapter for the PC (like the Zip "Zoom" or the Adaptec 1505, both about US$50). Or you could get the "Zip Plus," which has both SCSI and parallel interfaces.

Q. Jumper J213 on the A4000 motherboard looks like I can get 8M of Chip RAM. Does it work?

A. Yes, it does, but don't tell anybody. If it really worked, do you think everybody would still be using 2M of Chip? I'm always tempted to tell people to try it and report back if their machine blew up. No, it doesn't work, it was there for future chipsets that never materialized.

Q. I have a Connor hard disk, and...

A. There is no such thing. There is a brand whose name is spelled "Conner;" perhaps that's what you mean.

 

Aminet

Q. What is Aminet?

A. Aminet is a huge collection of Amiga software; in fact, it's the largest collection of computer software for any type of computer. Anyone with an Internet connection can use it, or it can be inexpensively obtained on CD-ROM from Cronus.

Q. How do I use Aminet over the Internet?

A. Step 1: Find your closest Aminet mirror. Look in the list at http://wuarchive.wustl.edu/~aminet/change.html.

Step 2: Access this mirror site with a web browser or FTP software.

Q. How do I find files on Aminet?

A. Download the INDEX file or INDEX.Z (the compressed version--use util/pack/gzip124x2.lha or the Unix compress program to decompress it). This is a complete listing of all the files, along with short descriptions.

 

Emulation

Q. Is there an Amiga emulator that runs on PCs or Macs?

A. Yes. See http://members.aol.com/swmillar/whatuae.htm.

Q. What about that other one, you know, the one that shows the Kickstart hand and then locks up?

A. It's a fake. It doesn't work and never has. Bean

Q. Can the Amiga emulate PCs or Macs?

A. Yes, and a host of other machines. See the misc/emu directory of Aminet and the Usenet newsgroup comp.sys.amiga.emulations for more information on the numerous commercial, shareware, and public domain emulator packages.

 

Disks And Storage

Q. Can PCs or Macs read and write Amiga floppy disks?

A. Short answer: Not for free. Get over it.

Longer answer: While the Amiga does use PC-type floppy drives, it uses the custom Amiga chips to control them, and writes entire tracks at a time with no sector gaps. This is beyond the capability of the standard PC floppy controller. There is a special floppy controller called the Catweasel that makes this possible; see: http://www.jschoenfeld.com.

Q. Can Amigas read and write MS-DOS floppy and hard disks?

A. Yes, no problem. Later versions of the Amiga operating system came with CrossDOS, which does just that. There are also some utilities of this type on Aminet. (Slight catch: many Amigas have only double-density floppy drives; on these machines, you can only use 720K MS-DOS disks.)

Q. Can Amigas read and write Macintosh floppy and hard disks?

A. Yes, within hardware limits: most Amigas have only double-density floppy drives, and they are incompatible with the older multi-speed Apple 800K drives, as is pretty much everything else. Desktop A4000s came with high-density drives, which can read and write Mac high-density disks. See misc/emu/CrossMAC_Demo.lha on Aminet.

Q. Will high-density diskettes work when formatted to double-density?

A. Not reliably. It'll often seem to work, then fail at the worst possible moment.

Q. My Amiga has a double-density 880K floppy. If I replace it with a regular high-density PC floppy drive, will I be able to use high-density disks?

A. No. Amiga high-density floppy drives are modified versions of those used in the PCs. See hard/hacks on Aminet for experimental projects on modifying standard drives.

Q. Is there a way to attach and use unmodified high-density PC floppy drives with standard Amigas (A500, A1000, A2000, A3000, A4000)?

A. Yes, the Catweasel: http://www.jschoenfeld.com.

Q. Do the Iomega Zip and Jaz drives and Syquest EZ and SyJet drives work on the Amiga?

A. The SCSI and IDE versions, yes. There are both commercial and PD utilities for using the custom features of the Zip, and you may need to use a PC or Mac running the Jaz tools to disable the verify option of that drive. Otherwise, treat these just like hard disks.

Q. Can I read MS-DOS-formatted Zip, Jaz, and EZ disks on the Amiga?

A. Yes. See the Aminet files disk/misc/ZIPMount_12.lha and disk/misc/MountDos100.lha.

Q. Can I use 3.5-inch hard drives in the A1200?

A. Yes, although you might have to slightly modify the internal shield and heavily modify the IDE cable. And you might very well need to replace the power supply to cope with the drive's higher power needs. And set the MaxTransfer value to 0x1FE00 for all partitions. And realize that a 3.5-inch drive usually generates more heat than the 2.5-inch drives, so that might cause operating problems. And larger drives draw more power, which the A1200 might have a hard time supplying through the standard power connector; a direct power cable from the power supply to the drive is often needed. Other than that, it's pretty simple.

Q. Will EIDE drives work in the A1200 or A4000?

A. Yes. Plug it in, set MaxTransfer to 0x1FE00 for all partitions, and go. See the A1200 Hardware FAQ for information on slow spin-up and disabling reset of these drives.

Q. Will EIDE (ATAPI) CD-ROM drives work in the A1200 or A4000?

A. Yes, with the proper software and maybe a cable. Point your browser to Asimware, http://www.elaborate-bytes.com or search for "atapi" in the disk/cdrom directory of Aminet.

Q. How big can a partition be? How about a whole drive?
A. Safe limits: 2G per partition (or 4G, but there's a catch), 4G per drive. FFS can use partitions up to 4G in size, but some utilities will show partition sizes larger than 2G as negative values. If you're lucky, that's the only problem you'll have. If you must, there are some other options:

Beta FFS filesystem from Amiga International: http://www.amiga.de/files/index.html.
giga.device: (device driver) disk/misc/giga171.lha on Aminet.
Guru-ROM: (replacement ROM for GVP and A2091 controllers) Support for drives larger than 4G. Available from Cronus.

Q. Will low-level formatting ruin my hard drive?

A. Maybe, but probably not. On a few old IDE drives, it might. Most recent IDE drives simply ignore the low-level format command and pretend they did it. For SCSI, you should generally not need to low-level format the drive (and some SCSI drives ignore the command, too). If you must do a low-level format, make sure there are no power interruptions and that you give it adequate time to finish. A full low-level format can take quite a while, half an hour or more for large or slow drives.

Q. I interrupted a low-level format on a hard drive before it completed. Now the drive won't work. What happened?

A. Most SCSI drives will go into a "stupid" mode if a low-level format is interrupted. In this mode, the drive knows there isn't a complete format, and refuses to do anything *except* a low-level format. The cure is to do a full low-level format and let it complete. Some people find that the only way to do this is with a PC SCSI system. IDE drives generally don't have this problem, since most now ignore the low-level format command.

Q. My friend and I have the same hard disk, but our parameters (blocks per track and number of heads and such) are wildly different. Both machines work, though. Why?

A. SCSI and IDE drives both work by block number. The computer requests a read or write to a certain block number, and the drive handles the rest. As long as the settings (heads*blockspertrack*cylinders) don't go over the total number of blocks available, it'll work. The heads, blockspertrack, and cylinders parameters are really mostly vestigial (like your appendix), and may someday be replaced with a "total blocks" value (unlike your appendix).

Q. How do I use a tape drive from the Amiga?

A. There's commercial and shareware software (look in the Aminet biz/demo directory). Then there's BTNtape, a PD tape device handler (on Aminet, disk/bakup/BTNtape30.lha). With this and most of the Amiga variants of the Unix "tar" program (in the util/arc directory of Aminet), you can read and write tapes that are interchangeable with other systems.

Tar for MS-DOS: ftp://ftp.mcs.com:/mcsnet.users/les/dos-gnutar/
Tar for Mac: ftp://ftp.amug.org/pub/amug/bbs-in-a-box/files/util/s/suntar-2.1.sit.hqx

Q. Will a tape drive made to connect to a PC's floppy or IDE cables work on the Amiga?

A. No, unless there's a special driver via the Catweasel controller. See: http://www.jschoenfeld.com.

Q. Why does the A2091 SCSI controller run so slowly in the A3000 or A4000?

A. Because the A2091 can't DMA to 32-bit RAM. The Guru ROM for the A2091 can help; also see the A4000 Hardware Guide section on the A2091 for more details on the problem (a pointer to the Guide is at the end of this document), or various programs in the disk/misc and hard/drivr directories of Aminet.

Q. Does the A3000's SCSI interface support "Fast SCSI"?

A. [by Ralph Babel] No, but upgrading it to do so is *extremely* simple: First, replace the standard WD33C93A SCSI chip by a WD33C93*B*. Be sure to provide the appropriate input clock on pin 7 (DIP) as described in section 3.1.16 of the WD33C93B data sheet. Finally, rewrite Commodore's scsi.device driver to select the proper clock divisor (see section 3.1.3); take the new input clock into account when dealing with incoming and outgoing SDTR messages, and set the WD's FSS bit accordingly. The driver should replace the one in ROM.Bean

Q. Hey! There's a "scsi.device" loaded on my A4000, but I thought I only had IDE drives. Do I have a SCSI interface, too?

A. No. The desktop A4000 only has an IDE interface built in, but, in a stunningly confusing move, the software driver for it is called "scsi.device". Clever, huh? (The A4000T does have a SCSI interface built in, but the software names are still screwed up.)

Q. What SCSI controllers are available for the A4000?

A. The A4091 and Fastlane are both Zorro-3 Fast SCSI-2 controllers, but can be difficult to find. Fast SCSI-2 controllers are available for accelerators, either built-in (Warp Engine) or optional (Cyberstorm). If the slower performance of plain SCSI-2 is acceptable, most Zorro-2 boards work in the A4000, although some are quite slow; of the Zorro-2 boards, the most popular are the Oktagon and DKB Rapidfire.

Q. After installing a removable media device (CD-ROM, Zip drive, or such), the Amiga's hard disk light flashes every few seconds. What's happening?

A. The system is polling the removable media device so it can detect when a disk has been changed. This is normal.

 

Memory

Q. Is there an adapter to use SIMMs for the motherboard memory in an A3000?

A. Yes. See http://users.informatik.fh-hamburg.de/~plewka_j for one, or email 75507.317@compuserve.com for another.

Q. Does the Amiga use special SIMMs? Can they use SIMMs with parity?

A. Amigas that use standard 72-pin SIMMS (not all of them do) will work with either 32-bit (without parity) or 36-bit (with parity).

Q. Can I use an 8M SIMM on the motherboard of an A4000?

A. Yes, usually:

  • Some A4000s (possibly older revisions) may only recognize 4M of an 8M SIMM.
  • The low-profile sockets used in the desktop A4000 are not made to take double-sided SIMMs, and most 8M SIMMs are double-sided. They'll still make contact, but some other means of holding them in place must be found.
  • The motherboard Fast RAM limit is still 16M, so at most you can only use two 8M SIMMs, and they must be in sockets 1 and 3.
Q. Can I use a 16M SIMM on the motherboard of an A4000?

A. Possibly. It may depend on the revision of the motherboard.

Q. Can EDO SIMMs be used in an Amiga?

A. In some of them, yes. It depends on the particular model:

All DKB boards (reported by DKB)
The A4000 motherboard
The Warp Engine
Blizzard 1230 and 1260

Still, try before you buy for any RAM expansions. Unless the RAM expansion has specific provisions to take advantage of EDO SIMMs, they won't run any faster than normal SIMMs.

 

Expansion

Q. My A2000/A3000/A4000 has PC ISA slots. Can I use PC cards in there?

A. Those slots only have power connections. Some ISA cards only need power, and they'll work (some timebase correctors, for instance). For anything that needs the logic signals, a bridgeboard of some type is needed. This can be either a PC hardware emulator, or a special purpose board made just to allow the use of PC cards. See http://www.infinet.com/~erd/GG2 for one possibility.

Q. My Bridgeboard doesn't want to work with a 68020/030/040 system. Why?

A. Try disabling the processor's caching.

Q. Can the 8-bit ISA slots in an A2000 be extended to 16-bit AT-style by simply soldering in the extra connector?

A. Yes.

Q. If I add a math coprocessor (FPU), will my machine run faster?

A. Only on floating-point math, and the operating system and most productivity software doesn't use much (or any) floating-point math. The major use for FPUs is for ray-tracing graphics software.

Q. The A3640 processor board can be used in an A3000, right? How?

A. See http://wwwcip.informatik.uni-erlangen.de/user/orknorr/a3640.html.

 

Monitors

Q. Will a CGA monitor work on an Amiga?

A. Yes...barely. It'll only display 16 colors, and probably only in NTSC. There are those of us who say that even a color composite monitor is better. Check the local pawn shops.

Q. Will an EGA monitor work on an Amiga?

A. If it does CGA mode and you can come up with the appropriate interface circuitry, it'll work as CGA. See the previous question for comments on using CGA.

Q. Will the 1084 monitor work on a PC?

A. Only if you have a genuine CGA board in the PC (not a VGA board emulating CGA), and are willing to build an appropriate adapter cable. It'll be mostly useless with modern PC software.

Q. Can I use a VGA monitor on the Amiga?

A. A multisync-type VGA monitor that syncs from 15 KHz and up will work with all Amigas, but most recent monitors don't sync that low (standard VGA is 31.5 KHz). The A3000 has a built-in deinterlacer port that will work will all standard VGA monitors, and equivalent boards can be added to the A500, A2000, and A4000.

Other options:

ECS and AGA machines (the A3000 and later A500s and A2000s) can also display doubled modes. These modes range in frequency from about 23 KHz up to about 29 KHz. The VGAOnly "monitor driver" will force these screen modes to operate at even higher frequencies so that they can be used on some pickier monitors. It's not really a driver; its only purpose is to raise the frequencies of the other drivers.

Q. What kind of cable do I need to connect a VGA or multisync monitor to the Amiga DB23 video connector?

A. The good old silver DB23-to-HDD15 adapter that came with the A4000 is available from many mail-order or local dealers, or see the Aminet file hard/hack/ami2vga.lha, or see the Connecting VGA Monitors section of the A4000 Hardware Guide.

Q. I have this goofy monitor that they were throwing away at work. It has some connectors and stuff. Will it work with my Amiga?

A. Maybe, maybe not. You'll need to find out the sync frequencies this monitor can use. You'll need to find out the pinouts and possibly other technical details, and may have to make an adapter cable for it. If the monitor is of the fixed frequency variety, you might be able to use a graphics card to drive it. Or not.

 

Networking

Q. Can I network my Amiga with my PC over a serial cable?

A. Yes. See comm/misc/PC2Am308.lha on Aminet, and other files in the same directory.

 

Miscellaneous

Q. My somewhat older Amiga doesn't have AmigaOS 3.1. It seems kind of expensive--is it worth it?

A. Yes. Get it.

Q. Does a PC mouse work on the Amiga? Can I use an Amiga mouse on a PC?

A. Not directly, because the two are electrically different. See the hard/hack section of Aminet for ways to modify some PC mice for use on the Amiga; also see hard/drivr/SerMouse221.lha which will let you use a PC serial mouse on the Amiga. Some commercial hardware adapters have been produced, too; see http://www.raach.com/bestellung_e.html. Finally, if you need a new Amiga mouse, consider that the old A1000 mice will work with later Amigas, although you might need an extension cable or adapter due to the right-angle connector on the A1000 mouse cable.

Q. Does a PC keyboard work on an Amiga?

A. Not directly, but adapters are available to connect them. See:

http://www.nationalamiga.com/i-insert104.html
http://www.paxtron.com

Q. I've heard of a software emulator called SoftAGA that provides AGA compatibility for machines without the AGA chipset. Does it work?

A. It's a fake, a joke. You can't upgrade your hardware by changing software, any more than you can grow taller just by concentrating on it.Bean

Q. Will an external modem for a PC or Mac work with the Amiga?

A. Yes, with the appropriate cable. Be aware that some pins on the Amiga serial port supply power, and should not be hooked up. On the other hand, most modems don't connect anything to these pins, so it's usually not a problem. The safest way to connect an external modem is to use a 9-wire serial cable (only pins 1-9 and 20 connected).

Q. My clock battery has fuzzy white crud on it, but it still keeps the time. Does it need to be replaced?

A. Yes. Your battery is leaking, and the acid can eat into the motherboard. To do it right, you take out the motherboard and desolder the battery. It may be possible to clip off the battery leads from the top, without taking out the motherboard. For a replacement, you can use a standard PC-type 3.6v nicad, a cordless phone nicad, or one of the high-capacity capacitors (1.0F) now being used for this kind of thing.

Q. The instructions for my new modem say that it can communicate with the computer at 57600 bps or even faster, but the Prefs/Serial program only goes up to 31250. How can I set this?

A. Terminal programs ignore the Prefs/Serial settings. Each terminal program has its own setting, perhaps under a Settings or Preferences menu or the equivalent. Set the speed there, and don't worry about the Prefs/Serial program (it is very rarely used, and usually only by those with serial printers). The Amiga's serial hardware is not particularly fast, and you might have data corruption problems operating the serial port at high speeds; there are replacement serial.device programs on Aminet in the comm/misc directory which attempt to compensate for this.

 

Other FAQs That Help Answer Irritating Questions

A1200 Hardware FAQ
A4000 Hardware Guide
Amiga Books FAQ
Amiga FAQ: docs/misc/AmigaFAQ.lha on Aminet.
CDROM FAQ: docs/help/CDROM35.lha on Aminet.
Networking FAQ
SCSI Examples
Zip Drive FAQ: docs/help/AmigaZipFAQ12.lha on Aminet.

BACK TO AHG

-

Latest updates to the Amiga History Guide. (more)


-
· Amiga Hardware
· Amiga History.de
· Amiga Magazine Rack
· Amiga-news(en)(de)
· Amiga.org
· Amiga World
· AmigaOS 4.0
· Amiga University
· Commodore Retrobits
· Dave Haynie archive
· Lemon Amiga
· MorphOS Support
· morphos-news.de

-

Other interesting items in the archive!


-  

--

home · changes · amiga history · features · amiga models
magazines · technical · interviews · internet links · downloads