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- Path: menudo.uh.edu!usenet
- From: markus@techfak.uni-bielefeld.de (Markus Illenseer)
- Newsgroups: comp.sys.amiga.reviews
- Subject: REVIEW: Commodore A2060 Arcnet card
- Followup-To: comp.sys.amiga.hardware
- Date: 20 Feb 1994 23:38:42 GMT
- Organization: The Amiga Online Review Column - ed. Daniel Barrett
- Lines: 403
- Sender: amiga-reviews@math.uh.edu (comp.sys.amiga.reviews moderator)
- Distribution: world
- Message-ID: <2k8sa2$2cf@menudo.uh.edu>
- Reply-To: markus@techfak.uni-bielefeld.de (Markus Illenseer)
- NNTP-Posting-Host: karazm.math.uh.edu
- Keywords: hardware, telecommunications, Arcnet, Zorro II, commercial
-
-
- PRODUCT NAME
-
- A2060 - Zorro-II based Arcnet Card for Amiga
-
-
- BRIEF DESCRIPTION
-
- The A2060 Arcnet Card is a true network device for the Commodore
- Amiga. It has become cheap lately and thus is a good alternative to other
- network devices.
-
-
- AUTHOR/COMPANY INFORMATION
-
- Name: Commodore Business Machines
- Address: 1200 Wilson Drive
- West Chester, PA 19380
- USA
-
- [Varies for other countries]
-
- DISTRIBUTION
-
- The card is available from every good Amiga dealer and mail order
- company. However, the card is no longer produced, and thus the second-hand
- market is open to all prices.
-
-
- LIST PRICE
-
- Suggested retail price is DM 126.- or about $70 (US).
- Street price is about DM 90.- or about $52 (US).
-
-
- SPECIAL REQUIREMENTS
-
- HARDWARE
-
- Amiga with Zorro-II or Zorro-III slots: A2000, A3000, or
- A4000.
-
- Does not work with A500, A600, A1200.
-
- At least 512KB of RAM.
-
- SOFTWARE
-
- Requires networking software such as:
-
- AS225R1 TCP/IP clients;
- Envoy network file system and network protocol;
- Enlan DFS
- Oxxi Novell Client
- AmiTCP TCP/IP
-
- and the SANA-II device.
-
-
- MACHINES USED FOR TESTING
-
- Amiga 2000
- Tested with 1 and 2 MB Chip RAM.
- 4 MB of 16-bit RAM
- A2630 accelerator board (4 MB of 32Bit RAM)
- (The accelerator board is of course not required.)
- A2091 SCSI adapter with several hard drives
- AmigaDOS 2.04 and Kickstart 37.175.
-
- Amiga 3000, 2 MB Chip RAM, 8 MB Fast RAM, and several hard drives.
- AmigaDOS 2.04 and Kickstart 37.175.
-
- For some further tests, a A2065 Ethernet card was used.
-
-
- REVIEW
-
- In a general overview, I shall describe the card and the required
- software to connect Amiga machines. I then will review the installation and
- the functionality of the card and the software.
-
-
- GENERAL OVERVIEW
-
- Arcnet is a basic hardware protocol for information exchange between
- computers. Onced connected, these computers represent a Local Area Network
- (LAN) and allows a group of people to share resources through the network on
- other machines at other locations. The main computer in the network is
- commonly known as the "file server," and the other computers are known as
- "clients."
-
- The Arcnet networking system is very old, introduced in the early
- 1980's, and was popular in the days of IBM XT compatible machines. As XT
- machines had an 8-bit bus subsystem, and the Arcnet Interface was not the
- fastest available, and was soon replaced by the faster ethernet protocol.
-
- Still, Arcnet is cheap and reliable, which makes it useful for small
- LANs and simple network sharing. Of course, it has been improved upon in
- both speed and functionality.
-
- The manual claims that Arcnet is able to support up to 256 nodes
- (machines) and that the speed is about 2.5 Mbps (megabits per second).
- Let's see what we really get.
-
-
- REQUIRED SOFTWARE
-
- On top of the hardware protocol Arcnet, we need software to provide
- file sharing or other kinds of network services. Available for the Amiga
- are the following protocols:
-
- Commodore AS220 R1 TCP/IP stack & clients (never made available :-)).
- Commodore Envoy file system and network protocol (available now!).
-
- Enlan DFS DEC-Net software.
- Oxxi Novell Client software.
- AmiTCP freely distributable TCP/IP stack for the Amiga.
-
- The TCP/IP stack protocol is very common in most LANs, and is also
- used in the Internet. It does provide clients to transfer files to and from a
- remote machine or server (ftp, rcp, nfs), run programs on a remote machine
- (rsh, telnet, rlogin). It also provides servers (daemons) to make files
- available for other machines (ftpd, nfsd) or to allow other people in the
- LAN to start programs on the Amiga (telnetd, rlogind).
-
- TCP/IP allows you to connect computer platforms other than Amiga to
- your LAN; i.e., Unix platforms or even PC-based LANs (if they can be
- connected with Arcnet).
-
- The Enlan DFS system allows you to connect your Amiga to a LAN with
- Digital Equipment DECstations running DECNet. Just one problem: DEC does
- not support Arcnet.
-
- Oxxi provides a Novell Client for the Amiga and allows you to share
- the provided services of a Novell LAN (based on Arcnet).
-
- AmiTCP currently is the only available TCP/IP stack protocol for the
- Amiga, as AS225 R1 from Commodore is no longer supported and AS225 R2 is
- still not available. AmiTCP is freely distributable and is available on the
- Aminet ftp sites. As full source code is provided, it is possible to
- program your own clients.
-
- The Commodore Envoy system is available right now and is probably
- the best choice for Amiga-only LANs. Envoy can be purchased from Amiga
- dealers and mail order companies. A review of Envoy will probably follow
- soon.
-
- Currently it is not possible to run AmiTCP and Envoy at the same
- time without problems (gating).
-
- Between the bottom layer Arcnet hardware and the top layer software
- (TCP/IP, DECnet, Envoy), there is a middle layer which handles data transfer
- between the hardware and the software protocols. This aids hardware
- independence. On the Amiga, this layer has been defined by Commodore and is
- known as "SANA-II." This is the hardware-dependent layer and provides
- device drivers for the hardware which can be then accessed by the software
- layer.
-
- Hardware: Arcnet Ethernet Serial Parallel
-
- \ | / /
-
- Interchange: SANA-II Interface
-
- / | \
-
- Software: TCP/IP Dec-Net Envoy
-
-
- The SANA-II software -- that is, device drivers -- is freely
- distributable and can be found on Aminet or Fish Disk 779 (and possibly
- later Fish Disks).
-
- For the A2060 Arcnet Card, we need the A2060.device.
-
-
- INSTALLATION
-
- The A2060 card comes in a box together with a 2-meter long, shielded,
- coaxial cable, a BNC-T connector, one Terminator Cap and a small (English)
- manual.
-
- The card is a full-length card for the A2000 which also fits easily
- into the A3000 and A4000. The installation is very easy but should be done
- by a qualified technician if you have two left thumbs.
-
- [MODERATOR'S NOTE: If you are not comfortable opening up your
- Amiga, then you should have the work done by an authorized Amiga
- service center. Opening your Amiga yourself may void your warranty,
- and careless work may even damage the machine. - Dan]
-
- The manual explains in detail the installation of the card into an
- A2000, but the explanation can be adapted for the A3000 and A4000.
-
- Now we come to the step where we connect the machines.
-
-
- BUG!
-
- The manual explains that the A2060 ARCnet uses a bus network layout.
- Unfortunately, this is only partially correct, because most of the new A2060
- cards (produced in the years 1992 and 1993) have a hybrid chip (the part on
- the card which is responsible for the communication on the cable) which
- allows only a star network configuration.
-
- We made lot of tests before we detected this bug. It is impossible
- to connect more than 4 cards in a star network, and thus the claimed 256
- nodes in the bus can never be achieved without any prevention. You either
- need to have active hubs and passive hubs (some sort of expansion or
- repeater in the bus) or need to exchange the faulty hybrid chip. The latter
- is by far cheaper.
-
- The hybrid chip which is able to drive the bus network is named HCY
- 9058, and the star network hybrid HCY 9068.
-
- Tests showed that once this patch is done, it is possible to connect
- more than 8 Amigas without any problems. If you don't have more than 4
- machines to connect, don't bother about this problem.
-
- You can circumvent the problem using gateways; i.e., an ethernet
- backbone or a machine with 2 ARCnet-cards.
-
-
- ANOTHER BUG!
-
- The manual has a funny bug, which is really nasty - probably it is
- not the manual but an error in the typesetting. The explanation of the
- DIP-switch is reversed by 180 degrees. This means that the DIP-switch '1' in
- position 'ON' enables not the address '1', but the address '127'. And all
- DIP-switches moved to the position 'ON' will yield '0' but not '255'. And
- '0' is not supported.
-
-
- WORK
-
- After the (tricky) installation part, we come to the first tests.
- Running Envoy, we can export all or part of a hard drive (or any other
- device) to the network. Doing a simple 'DiskSpeed' allows us to test the
- speed of the card. You will see that the Arcnet is a bottleneck, it is not
- as slow as you might think. Here are the test results:
-
- ======================== RESULTS BEGIN HERE ==============================
- Comment: b-alfa: is remote hard-drive.
-
- MKSoft DiskSpeed 4.2 Copyright ) 1989-92 MKSoft Development
- ------------------------------------------------------------
- CPU: 68030 AmigaOS Version: 37.175 Normal Video DMA
- Device: b-alfa: Buffers: <information unavailable>
- Comments: DiskSpeed 4.2
-
- CPU Speed Rating: 1371
-
- Testing directory manipulation speed.
- File Create: 6 files/sec | CPU Available: 83%
- File Open: 12 files/sec | CPU Available: 72%
- Directory Scan: 69 files/sec | CPU Available: 75%
- File Delete: 19 files/sec | CPU Available: 77%
-
- Seek/Read: 15 seeks/sec | CPU Available: 68%
-
- Testing with a 512 byte, MEMF_FAST, LONG-aligned buffer.
- Create file: 11352 bytes/sec | CPU Available: 75%
- Write to file: 12064 bytes/sec | CPU Available: 74%
- Read from file: 16979 bytes/sec | CPU Available: 65%
-
- Testing with a 262144 byte, MEMF_FAST, LONG-aligned buffer.
- Create file: 8589 bytes/sec | CPU Available: 87%
- Write to file: 10187 bytes/sec | CPU Available: 85%
- Read from file: 74017 bytes/sec | CPU Available: 46%
-
- Average CPU Available: 62% | CPU Availability index: 850
-
-
-
- Comment: b-ram: is remote ram disk.
-
- Device: b-ram: Buffers: <information unavailable>
-
- CPU Speed Rating: 1371
-
- Testing directory manipulation speed.
- File Create: 15 files/sec | CPU Available: 66%
- File Open: 16 files/sec | CPU Available: 64%
- Directory Scan: 273 files/sec | CPU Available: 27%
- File Delete: 37 files/sec | CPU Available: 61%
-
- Seek/Read: 20 seeks/sec | CPU Available: 59%
-
- Testing with a 512 byte, MEMF_FAST, LONG-aligned buffer.
- Create file: 22744 bytes/sec | CPU Available: 53%
- Write to file: 23525 bytes/sec | CPU Available: 52%
- Read from file: 23991 bytes/sec | CPU Available: 52%
-
- Testing with a 32768 byte, MEMF_FAST, LONG-aligned buffer.
- Create file: 93102 bytes/sec | CPU Available: 24%
- Write to file: 100012 bytes/sec | CPU Available: 20%
- Read from file: 80988 bytes/sec | CPU Available: 41%
-
- Testing with a 262144 byte, MEMF_FAST, LONG-aligned buffer.
- Create file: 9346 bytes/sec | CPU Available: 86%
- Write to file: 7454 bytes/sec | CPU Available: 88%
- Read from file: 87255 bytes/sec | CPU Available: 38%
-
- Average CPU Available: 46% | CPU Availability index: 631
- ======================== RESULTS END HERE ================================
-
- Now where is the claimed 2.5Mbps? Remember that "bps" means "Bits
- per second"; thus, we have to divide 2500000 by 8 = 312500 Bytes/sec, makes
- about 300K/sec. The above best value is 100K/sec.
-
- We have to consider that the 2.5Mbps are achieved only on the
- hardware layer of Arcnet. The software protocol has its own overhead,
- resulting in a loss of speed. This is about 10% of the real transferred
- amount of data.
-
- Then we have to think about that the Arcnet Card is interrupt driven
- (polled I/O), and one interrupt on the Amiga yields into a busy system. To
- reduce traffic inside the Amiga, the driver uses the 4 buffers of the Arcnet
- hardware as a simple FIFO buffer. Unfortunately the 2060.device has some
- bugs in this buffer which yields lost packets and packet collision which
- will increase the traffic on the Arcnet bus.
-
- You can see the mentioned problems in the last test, where a 200K
- file was used, which was transferred in the slow rate of 7K/sec.
-
- Unfortunately, I was not able to connect my Amiga to an Arcnet-based
- PC-LAN, because I couldn't find one. Anyway, I don't see any reason why it
- would be impossible to connect Amiga-Arcnet to PC-Arcnet: the hardware
- protocol is the same, and if one uses TCP/IP as software layer it should be
- possible to interchange data.
-
- Further tests were done using AmiTCP in a small LAN consisting of
- only Amiga platforms. The speed was exactly the same, which shows that the
- A2060.device is the bottleneck.
-
- Also one machine was used as a gateway from Arcnet to Ethernet.
- Hence, it was possible for Arcnet-based machines to use resources of
- Ethernet-based machines. Using TCP/IP, it was even possible to connect the
- entire LAN to the Internet. This test was very successful, with just one
- minor problem: the gateway is very busy, and it is really recommended to
- have either a dedicated system or a fast machine for the gateway.
-
- Small tests at an Amiga meeting showed that it is possible to
- connect the machines using long cables, not just the provided 2-meter cables.
-
-
- LIKES AND DISLIKES
-
- You get a good service for a cheap price, the reliability is high,
- and speed is quite good. I like the fact that you can easily connect several
- machines to the bus.
-
- I dislike the bugs. The A2060.device is not the best although it is
- stable. Also the bus/star network 'bug' provided by the wrong kind of hybrid
- interfaces is somewhat nasty due to the impossibility to connect more than 4
- machines.
-
-
- COMPARISON TO OTHER SIMILAR PRODUCTS
-
- There is no other Arcnet-Card for the Amiga available, thus we have
- to compare it with SLIP which is driven over the serial line (and is of
- course far slower), and with Ethernet (Commodore A2065 card) which is about
- 5 times faster.
-
- Close to Arcnet comes a floppy port based system (e.g., Amoknet)
- which can also connect A500/A600 and A1200 computers. This kind of network
- is an Amiga-only network, and is reliable, but is somehow a system hog and
- uses almost all the resources of the Paula chip.
-
- Compared to the evergreen ParNet (and the successor PNet or liana,
- both devices for SANA-II), Arcnet is by far more stable, because once one
- machine in a Parnet network crashed, the other had to reboot, too.
-
-
- CONCLUSIONS
-
- A reliable product which has some faults but is very usable and
- offers much for its low price. I'd rate it 4 out of 5 stars.
-
- The last star can be achieved if a new A2060.device is available
- which fixes the buffer problem and offers better speed.
-
-
- COPYRIGHT NOTICE
-
- Copyright 1994 Markus Illenseer. All rights reserved.
-
- You can contact the author at:
-
- Markus Illenseer, Kurt Schumacherstr. 16, 33613 Bielefeld,
- GERMANY
- Voice: ++49 (0)521 103995
-
- markus@techfak.uni-bielefeld.de
-
- ---
-
- Daniel Barrett, Moderator, comp.sys.amiga.reviews
- Send reviews to: amiga-reviews-submissions@math.uh.edu
- Request information: amiga-reviews-requests@math.uh.edu
- Moderator mail: amiga-reviews@math.uh.edu
- Anonymous ftp site: math.uh.edu, in /pub/Amiga/comp.sys.amiga.reviews
-