- Multiple Internet Service Providers
- Modifying the Xetec SCSI host adapter
- Amiga parallel port vs. the clone port
- Even more hints, about Internet security and the Amiga.
Also, many of the items in these AmigaHints files require knowledgeable use of a VOM (volt-ohmmeter) and a soldering iron. If you are not capable of modifying electronic equipment, it would be wise for you to consult someone who is.
There are no complicated graphics on this page. It is mostly ASCII, so that even those with just a text based browser will have no difficulty reading this information.
In late 1999, the long-promised update to the Amiga operating system
became available. The author of this page is using Amiga OS 3.5 on the
A3000 used to prepare this page. But you must have at least a 68020 cpu
for OS 3.5 to work. My A500 has only a 68010, so that machine still
runs Amiga OS 3.1.
For those of us with less powerful Amigas,
here are some programs and updates which will improve the
operation of your Amiga OS 3.1 system.
Canon Australia officially supports the Amiga with large files containing drivers for many
different models of Canon printers.
For a rather complete list of popular printer drivers you should
look at the page referenced in the line above.
Good Stuff if you have at least a 68020 CPU
And if you have a 68040 or 68060
As always, I advise you to read and follow the instructions included with each program
and file listed here. I know you won't do it, but my conscience urges me to include that sentence.
If you have suggestions or additions to this list, my e-mail address is all over this page.
rdavis@nyx.net
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The Amiga 500 can supply power to devices plugged into the 86-pin expansion port through the port on the left side of the computer. Pins 5 and 6 deliver +5 volts, pin 8 delivers -12 volts, pin 10 delivers +12 volts and pins 1,2,3,4 are the ground return.
The 5-volt line is most important. The A500 can deliver only a fraction of an ampere before the voltage drop through the Radio Frequency Interference filter (EMI1702) causes problems for the RAM expansion, SCSI hard drive adapter, or whatever is drawing power from the expansion connector.
The solution is to add a jumper wire to bypass the EMI device. This may cause problems with interference to nearby television or radio reception. If it does, it is your fault, and you will have to undo the modification to your A500.
To add the jumper, you will have to remove the top of the plastic case on your A500, and then remove some or all of the interior shielding to get to the component parts on the motherboard. If you don't know how to do that, leave the work to someone who does.
Then, the quick fix is to add a short jumper wire connecting the two outer pins on EMI1702, next to the 86-pin expansion connector. The better fix is to add a jumper wire from the plated through hole connected to pins 5 and 6 on the expansion bus and connect the other end of the wire to a point on the 5-volt bus inside the computer. You can use your voltmeter to find an appropriate point for the connection, perhaps near the square DIN power supply connector. then you put the shield back in place, and reassemble the A500 plastic case.
In my case the modification made the difference between my external 8-meg RAM expansion working or not. The voltage to the RAM was just too low at about 4.6 volts until I made the mod. With the jumper in place the voltage increased to 4.8 volts, and the RAM expansion works.
As stated above, I will take no responsibility for any problems or troubles caused by your modification to your computer.
rdavis@nyx.net
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When your Amiga keyboard refuses to recognize keypresses, you may solve the problem by cleaning its interior connections. Amiga (and older Commodore) keyboards are quite simple. A printed circuit board has two open connections for each key. When you press a key, a conductive foam pad is pressed against the two metal pads on the printed circuit board.
The pc board is held against the key matrix by many tiny Phillips head screws. Don't lose any of those screws. Once you have the keyboard apart, clean the pc board with fresh running water and carefully dry it with a lint free cloth -- avoid paper towels.
If you have a particular key or keys giving you problems, examine the face of the conductive pads. If they are shiny, you may gently roughen them with a fine file, such as a nail file. Press on the key in question to force the pad up and into your reach.
It is possible to use the conductive pads from older (Vic-20, C-64) keyboards to replace the defective pads in your Amiga keyboard. You may have to trim the older pads to fit, and you may have to use other clever methods of fitting the pads into the Amiga keys, but I have done it, and you can if you think about it.
Then reassemble the keyboard, taking care not to over-tighten the many small screws. As always, if you have any problems or difficulties, they are your fault and I am not responsible for what you do to your computer.
rdavis@nyx.net
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Many Amiga owners have purchased the IOmega ZIP removeable media drive. And those with Xetec SCSI controllers have often not been able to get the ZIP drives to work. A couple of modifications to the Xetec card may fix the problem.
My first exposure to the ZIP drive was on an A2000, where the Xetec host adapter card did not communicate with the ZIP until "termination power" was applied via pin 25 on the Xetec card. Apparently, the ZIP drive does not have the option of internally applying the +5 volt pullup to its internal termination resistors.
An even larger disclaimer here ... I have only one Xetec SCSI card, a Xetec FastCard, which may not be identical to the one you have. The modifications described here worked OK on my FastCard.
Look at the solder side of the card, and see the connections for the 25-pin SCSI connector at the rear of the card. The pins are numbered like this:
----------------------------------------- (rear bracket)
-- 25 24 23 22 21 20 19 18 17 16 15 14 -- (solder side of pc board)
-13 12 11 10 09 08 07 06 05 04 03 02 01--
On the solder side of the FastCard, a ground trace runs in a circle around the connections for the 25-pin D-Sub connector. The first mod is to run a short wire from pin 24 to that ground bus. On my board, that wire is less than 5mm long.
The second mod is to hook up +5 volts to pin 25. You could just run a wire from pin 25 to +5 volts, but the proper way is to connect the power through a protective diode. The Amiga 3000 uses a type 1N914, but most any physically small silicon diode will work. Attach the banded end of the diode to pin 25 of the D-Sub connector, and the other end of the diode to +5 volts. Pins 5 and 6 of the FastCard bring +5 volts onto the board, and you can follow the traces from there. One convenient location for +5 volts is pin one of either of the termination resistors adjacent to the 5380 SCSI integrated circuit. Pin one of each of the resistors is marked with a square trace around the pin, and all three resistors have pin one connected together.
rdavis@nyx.net
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Have a look at the information below. Reference Amiga 500 / Amiga 2000 Technical Reference manual, page 4.
| Amiga | clone | |
| pin 1 | STROBE* | same |
| pin 2 | data bit 0 | same |
| pin 3 | data bit 1 | same |
| pin 4 | data bit 2 | same |
| pin 5 | data bit 3 | same |
| pin 6 | data bit 4 | same |
| pin 7 | data bit 5 | same |
| pin 8 | data bit 6 | same |
| pin 9 | data bit 7 | same |
| pin 10 | ACK* | same |
| pin 11 | BUSY | same |
| pin 12 | POUT | same |
| pin 13 | SEL | same |
| pin 14 | +5 volt pullup | AUTOFDXT* |
| pin 15 | ground | ERROR* |
| pin 16 | ground | INIT* |
| pin 17 | ground | SLCT IN* |
| pins 18-23 | ground | same |
| pin 24 | no connection | ground |
| pin 25 | Reset* | ground |
The clone port simply has more programming options than does the
Amiga port. It is not likely that anyone will be able to make
a cheap clone parallel port tape drive work on the Amiga.
rdavis@nyx.net
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Every few weeks, a series of exchanges about using the 68010
CPU appears in the comp.sys.amiga.hardware newsgroup. A somewhat
related discussion reappears whenever someone asks if putting a
higher speed 68000 in an older Amiga will speed up the computer.
First, just putting a 68000 rated at a higher speed will do
nothing. The speed of the CPU is not determined by what is
printed on the chip. The speed is determined by the computer
timing device, its "clock" which is separate from the CPU.
So putting a 10mhz 68000 in an Amiga means the Amiga won't
run any faster than with an 8mhz 68000. Think of it like this:
Which is faster? A Yugo travelling at 55 miles per hour, or
a Ferrari travelling at 55 miles per hour? Just because you
can go faster does not mean you are going faster.
Now there are hacks on Aminet which do change the clock speed
of the Amiga to speed up the CPU while keeping the necessary
parts of the computer at the necessary, slower speed. Some
commercial accelerators have used the same principle. AdSpeed
and Supra units come to mind. If you want to construct one of
the hacks, be my guest, and good luck.
Now about the 68010. That IC does exactly replace the
68000 in its socket in any older Amiga. And, that IC does
execute some instructions faster than does the 68000.
Some small loops and all of the more complicated math instructions
are faster on the '010 than on its older sibling. Therefore
the 68010 will run programs which use those particular
instructions faster than the 68000 will run the same programs.
But the speed up is not very great. My own tests on an A500
indicate ray tracing with Imagine is about five per cent
(5%) faster on the '010.
Many respondents to news postings caution potention users of
the 68010 to get the old program DECIGEL which will fix a problem
with one instruction on the 68000 which is not handled in the
same manner on the 68010. They tell everyone that some of their
software will crash without decigel.
That is garbage.
The particular MOVE instruction which messes up on the 68010
but not on the 68000 will also crash any computer using a 68020,
68030, 68040 or 68060 cpu. And all programmers have been aware
of that instruction and its problems since the mid-1980s. More
specifically, writers of compilers have made sure their code
generating software did not use that instruction as it was
defined on the 68000. It has been literally years since any
new software for the Amiga suffered from the MOVE SR,Destination
bug in the 68000.
So, the conclusion. If you want a small speed increase for your
older Amiga (A1000, A500, A2000) changing to a 68010 cpu will
do it. Since the speed up is small, it will likely be economical
only if you get the cpu chip free or for a very low price, and
if you are able to do the installation yourself, without paying
someone else to do the work.
I have 68010 cpus in both my A500 and my A2000. I paid $5.00
for four of the '010 cpu ICs at an Amateur Radio swap meet. For
a cost of $1.25 per cpu, it was worth it for a five per cent
speed up.
rdavis@nyx.net
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For the month of April, 1996, I am comparing the Internet Service Providers of Emporia, Kansas. My plan is to choose the best of the three and drop my accounts on the other two.
So I have to make my Amiga, running AmiTCP 4 and ppp 1.45 alternately connect to the ISPs, which we shall refer to as C, V, and S ... because their real names don't matter.
I had been starting my Internet connection by typing
internet from a shell. That script (sys:s/internet)
looks like this:
.bra {
.ket }
.key param
; Installed with iNTERiNSTALL 1.51
path >nil: amitcp:bin add
;
run >nil: execute >NIL: amitcp:bin/startinternet {param}
The startinternet script reads the ppp0.config file (env:sana2/ppp0.config) which tells the program to use the ppp.dial script (env:sana2/ppp.dial) to actually call the Internet Service Provider.
So to call multiple ISPs, I created a separate ppp.dial
script for each one. Those files are stored on my hard
drive as:
envarc:sana2/Vppp.dial
envarc:sana2/Cppp.dial
envarc:sana2/Sppp.dial
In these files, the telephone number of the ISP, username, and password are different for each script. Of course, other differences may exist in the logon procedures. Those differences may require additions or other changes to the scripts. Every ISP is different from all the others.
Then, instead of one sys:s/internet script, I created
three different scripts:
sys:s/callV
sys:s/callC
sys:s/callS
Here is the callV script:
.bra {
.ket }
.key param
; Installed with iNTERiNSTALL 1.51
path >nil: amitcp:bin add
;
copy envarc:sana2/Vppp.dial envarc:sana2/ppp.dial
copy env:sana2/Vppp.dial env:sana2/ppp.dial
;
run >nil: execute >NIL: amitcp:bin/startinternet {param}
And that script copies the appropriate ppp.dial script to the necessary directories on both the hard drive and the ram disk before calling the rest of the procedures which accomplish the connection to the Internet. Except for the first letter of the filename to copy from, the other two scripts are identical to this one.
So instead of typing internet to start my internet connection, I type either callv callc or calls and my Amiga calls the Internet Service Provider of my choice.
If you normally click on an icon to start your Internet connection, you will have to create separate icons for each ISP, and probably use xicon to execute the scripts. I shall leave that as an exercise for the reader.
rdavis@nyx.net
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