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- Path: inforamp.net!usenet
- From: wjustice@inforamp.net (wjustice)
- Newsgroups: comp.sys.amiga.hardware
- Subject: Re: New Buster in A4000
- Date: 10 Apr 1996 04:15:07 GMT
- Organization: InfoRamp Inc., Toronto, Ontario (416) 363-9100
- Message-ID: <7253.6673T1432T2370@inforamp.net>
- References: <4kdl1g$eca@toad.stack.urc.tue.nl>
- NNTP-Posting-Host: ts15-06.tor.istar.ca
- X-Newsreader: THOR 2.22 (Amiga;TCP/IP) *UNREGISTERED*
-
- Hi!
-
- I'd like to add a few comments, having run into the "unsocketed A4000
- problem" a few times:
-
- >Taka Torimoto (ccasttt@prism.gatech.edu) wrote:
- >: >I just upgraded from A3000 to A4000. In my A3000 I changed buster from
- >: >rev.7 to rev.11 just by changing the circuits. In my A4000 i noticed
- >: >that the buster was surface mounted and not in a socket.
-
- >: Noooooononono... that's IMPOSSIBLE!
-
- >: Both the A3000 and A4000 uses the Buster CHIPs...
-
- >There are 4000's with surface mounted busters. Only the first few were like
- >this. Unless you're very good at soldering and have the right equipment I'd
- >just bring it a company to get it fixed. It's very hard...
-
-
- 1. Are you sure that you need to upgrade? IMHO, the rev -09 Buster
- originally fitted (first surface mounted, then socketed) to the A4000
- more than does the job adequately for a lot of users. Users of the
- original A4091 SCSI controller (originally C=; then DKB) required the
- update to rev -11 Buster.
-
- I believe that the Fastlane SCSI controller works quite well with the
- original A4000 rev -09. (Not totally sure; someone correct me if I'm
- wrong).
-
- The onboard SCSI-2 available with the Warp Engine does not need an
- update, again rev -09 works just fine. (SCSI-2 speeds as well).
-
- 2. IMHO, the majority of A4000 users have added SCSI capability with less
- esoteric cards, using the existing A2091, GVP 4008, and even that
- ancient relic, the Supra Word-Sync. None of these cards need more
- than a rev -09 Buster in an A4000/040 (Don't see how an 030 version
- would change this).
-
- While doing this doesn't approach the speeds of a SCSI-2 read/write,
- the results are more than adequate for the users who wants to add
- CD-ROM (which can't even make full use of the original SCSI speeds),
- a tape backup, a Syquest drive (I guess I've just dated myself ;) ,
- yes our family still uses 44Mb Syquests, and a few 88Mb's. I have
- no experience with the larger, smaller Syquests, nor Zip drives.
-
- Still,I would expect that the newer removable hard disc media drives
- would behave in similar fashion and be supportable by many of the above
- listed SCSI "1" controllers. Again, please let me know if I'm wrong,
- or if someone has doubts.
-
-
- 3. In our family, we have three 4000/040's; mine and one each for each of
- my early teenage sons. I use a rev -11 Buster, it just happened to be
- lying about my parts bin, but I've also substituted it with the original
- -09 rev that came with the machine and have noticed absolutely no
- differences in performance - speed of disk read/writes, CPU access, etc.
-
- My setup - 2x120Mb 'original' A4000 IDE drives, a Supra Word-Sync
- controller, and so far, only one 120Mb Quantum SCSI installed internally.
- Hey, it's not SCSI-2, but I still get avg 1.3 MB/sec on the SCSI, and
- have the interface ready for a CD-ROM, etc.
-
- 4. My youngest son's A4000 is identical to mine, including the Supra Word-
- Sync, except he has a rev -09 Buster. He has no internal SCSI drives
- at this time, but uses an externally cased 44Mb Syquest to record his
- animations. Again no problems; in fact a transfer speed almost double
- to what we get when we use one of our Zorro II based A2500's. We have
- swapped between the rev -09 and the newest rev -11 with no noticeable
- difference to us.
-
- 5. My eldest son, had us install the GVP 4008 controller (SCSI-2
- 'compliant' controller plus space for 8MB of 16-bit ram) to give him
- extra SCSI hard drive access. We're a behind the-state-of-the-art
- and cannot afford Gig sized drives.
-
- He's also using a rev -09 Buster; we've interchanged and run tests,
- finding no discernable differences. (Now the GVP 4008 SCSI controller,
- that's another story.) He has a Sony 2x SCSI CD-ROM fitted internally,
- which for space an cooling airflow considerations meant that one of
- his original 120 Mb. IDE drives had to go. However he has more than made
- up for this by adding 1x240Mb and 1x120Mb SCSI Quantums. He also has
- an external 44Mb Syquest.
-
- 6. Of the three setups which I've described, all are easy to use, have good
- read/write speeds, are easy to add further SCSI peripherals to, and have
- been achieved on a much lower budget than the full SCSI-2 controllers,
- and hard drives would have cost, and which we could not achieve at this
- time. Excepting for the GVP 4008 unit, we have never had CPU useage or
- other problems. I am quite certain that the much advertised "GVP' Guru
- ROM would go a long way towards solving any minimal problems which this
- controller has caused us.
-
- 7. Reference, replacing your surface mounted rev-09 Buster, what is difficult
- for one person, is withing reach of another. If you are convinced that
- you must upgrase at this time, bear in mind that it is quite difficult to
- damage a PCB board, surace mounted or conventional. Problem is, there
- are a lot of leads on the Buster and you must heat, suck up the solder (ie.
- copper braided solder-wick) for an awful lot of leads.
-
- Most technicians always tell me that the typical rule in PCB work is to use
- a moderately high heat soldering iron; ie. get the heat on the lead, melt
- it, disconnect it, and get the heat off the chip, fast.
-
- SML repair, ideally, uses a small table, on which the SML PCB is placed and
- then high temperature air is directed, evenly onto the entire component to
- be installed/replaced. This sort of equipment is still too expensive for
- even the small, professional electronics repair facility. As the amount of
- SML boards increases, they are facing no choice but to invest in these
- tools. Still, I have found many who do the occassional chip replacement
- with conventional equipment.
-
- You can be a bit more liberal about 'overhating' the chip in question,
- given that a much larger proportion of its leads are in contact with a
- SML board (as opposed to a 'traditional' PCB board, and consequently with
- reasonable common sense, you can heat up a few leads at a time, prise them
- lose from the board, and then go on to the next few.
-
- Don't forget to take some 'cooling down' breaks and most important of all,
- watch for solder bridges. The leads on SML chips are much. much closer
- together, and constitute 'solder pads'. Solder bridges are inevitable.
- Trick is to find them and remove them before powering up.
-
- 8. Now a lot of Amiga owners are just not willing to undertake this sort of
- work. Just bear in mind that unless you send out your board to an
- authorized Amiga service centre, some service 'techs' out there will be
- kluding through all of this in a similar fashion. No offence meant to
- the well trained, well equipped, well experienced electronics service
- centres that are rapidly growing in SML technology. :) :)
-
- 9. So, I have presented several options in my opinion:
-
- -Do you really need to upgrade the Buster at this time?
- -It is quite feasible if you have reasonable soldering experience.
- -If you need to upgrade and don't want to do it yourself; make
- sure the service centre that you take it to is competent.
-
- Cheers,
-
-
- --Willy Tamm.......................wjustice@inforamp.net
-
-