Some Amiga 2000 Newbie Questions

[Huxley_D]

Hi guys!
I recently managed to win an auction for a Commodore Amiga 2000 from a local seller. The seller was great (and may be a source of more vintage gear in the future!), but not particularly knowledgeable about this particular machine. The A2000 I got is a plain-jane mode, but at some point in its life it underwent some significant upgrades:

First, it received a "Great Valley Products" Impact A4000-HC+8 - with a 70 meg SCSI hard drive. The slots on my board are empty, but the drive is fully functioning, loaded with software, and boots flawlessly!

Second, it got a Commodore-brand "A25000" RAM board with 2 megs of DRAM chips soldered on.

Finally, this A2000 has an A-MAX Macintosh emulator module. This strange rectangular brick connects (externally) the the rear of the A2000, and when outfitted with genuine ROM chips from a Mac 128k or 512k Mac, allows the Amiga to natively run (early!) Mac software. The 1st-gen A-MAX that I have will boot up to Mac OS 6.0.3, according to some info I found online.

I've gotten the system booted up, but I only have an older Commodore monitor (designed for the C64 and C128), so the Amiga 2000 is displaying a pretty shaky image in greyscale. I'm going to start scrounging online for a monitor more suited to what this machine is capable of! Also, we're experiencing a pretty good lightning storm here in Albuquerque, and the Amiga is clearly unhappy with the currently unstable power, so I'm going to play with it more tomorrow.

The A2000 I got actually came in its original box (in pretty good shape too), with the keyboard, mouse, and original power cord. The A-MAX (along with some other software and games, and a 2-channel hardware audio mixer / input box!) all have their original boxes, manuals and disks.

All-in-all a great find, and a really fun addition to my collection!  However, as I've only ever played with A1000's and 500's in the past, I've got a few questions about this machine that some of you might be able to help with:

1.  What's the best / easiest way to determine which model or revision this 2000 is (as in Rev. A / B / C)?

2.  What's the best / easiest way to determine what ROM this 2000 has, and what would be the ideal ROM for this system?  Perhaps a related question - what would be the idea version of the OS for this system?

3.  With the 8 RAM slots on the GVP board, how much RAM can I add to this thing?  I'd guess 8 megs, but I think I read that some of them could use more...

4.  Does anyone know a source for a PDF of the user manual for Amiga OS and / or the user manual for the 2000 itself?

5.  How does one determine exactly which CPU module is in a 2000?

Thanks for any help you can provide, and please bear with me as I get up-to-speed with this thing!

Huxley

[save2600]

I believe that lengthy AMax box you've got not only houses the Mac ROMS, but also provides a way to hook a Mac drive up to it. You'll still need to boot the AMax software and then Mac OS. 6.02 was popularly used with that setup.

Going down your list:

1) Old Amiga 2000's routinely have weakened power supplies at this stage of the game. Not a bad idea to replace the capacitors in them or hack your way to outfitting a PeeCee power supply for it.

2) Open up your Amiga 2000 motherboard... you'll see its revision clearly labelled in
the rear and near the video port. Look for more than just a letter. Yours might be a rev. 4 since you mentioned the old AMax box.

3) If possible, download and install Sysinfo from Aminet.net to learn about your
Kickstart revision if you don't want to poke around too much. The Kickstart chip is
under the drive plane and that requires you to remove 4 screws in the rear (power
supply) and three screws in the front. Also, without a HD plugged in - you'll see a hand
prompting you to insert a Workbench disk. The version of OS will be clearly visible. I
bet you have 1.3.

4) You know you have an expanded processor card if the slot just to the left is occupied and assuming you did not acquire this in Germany. Those German mobo's
routinely had a 1mb Ram card there. Not sure where you are posting from, but if you are from Germany and
it's an early enough revision motherboard, you're going to have more problems using that Fast Slot. Anyway...
sysinfo will also tell you what processor you have, what kind of Agnus and Denise chips as well. I'd guess you have just the 68000 though and that is suitable for running OS 1.3-3.1. 1.3 is the way to go if you're not going to be
doing much with the computer besides gaming from floppy. If you want to do more modern things with your late
80's era Amiga, you're going to want to install a 3.1 Rom and OS 3.1.
 
5)  8mb Fast Ram is the limit on Amiga's with the 68000 processor. To get more than
that, you'll have ram added about the 16-bit addressing of the Zorro II standard. In
other words, the nicer accelerator cards 030+ have ram slots and are configured as
32-bit ram. These types of cards typically allow you to add as little as 1mb 32-bit
Fast Ram all the way up to 128mb.

It's fun to tweak and upgrade Amiga's, especially if you have a specific task for it in
mind. IF you're looking to play the occasional game, you're likely not going to need to
soup her up too much. All depends on what you want to do with her.

Since you mentioned something about a slightly flaky power supply, I'd start with that
first. Either have it repaired or find another one. Chances are, the one you find later
will need servicing too anyway.

Accelerating your Amiga can be frustrating as hell for a myriad of reasons. You've
been warned. Find out what you'd like to do with this machine and we can further
advise you on what to do, where to go, etc.

[Tension]

I believe that lengthy AMax box you've got not only houses the Mac ROMS, but also provides a way to hook a Mac drive up to it. You'll still need to boot the AMax software and then Mac OS. 6.02 was popularly used with that setup.

Going down your list:

1) Old Amiga 2000's routinely have weakened power supplies at this stage of the game. Not a bad idea to replace the capacitors in them or hack your way to outfitting a PeeCee power supply for it.

2) Open up your Amiga 2000 motherboard... you'll see its revision clearly labelled in
the rear and near the video port. Look for more than just a letter. Yours might be a rev. 4 since you mentioned the old AMax box.

3) If possible, download and install Sysinfo from Aminet.net to learn about your
Kickstart revision if you don't want to poke around too much. The Kickstart chip is
under the drive plane and that requires you to remove 4 screws in the rear (power
supply) and three screws in the front. Also, without a HD plugged in - you'll see a hand
prompting you to insert a Workbench disk. The version of OS will be clearly visible. I
bet you have 1.3.

4) You know you have an expanded processor card if the slot just to the left is occupied and assuming you did not acquire this in Germany. Those German mobo's
routinely had a 1mb Ram card there. Not sure where you are posting from, but if you are from Germany and
it's an early enough revision motherboard, you're going to have more problems using that Fast Slot. Anyway...
sysinfo will also tell you what processor you have, what kind of Agnus and Denise chips as well. I'd guess you have just the 68000 though and that is suitable for running OS 1.3-3.1. 1.3 is the way to go if you're not going to be
doing much with the computer besides gaming from floppy. If you want to do more modern things with your late
80's era Amiga, you're going to want to install a 3.1 Rom and OS 3.1.
 
5)  8mb Fast Ram is the limit on Amiga's with the 68000 processor. To get more than
that, you'll have ram added about the 16-bit addressing of the Zorro II standard. In
other words, the nicer accelerator cards 030+ have ram slots and are configured as
32-bit ram. These types of cards typically allow you to add as little as 1mb 32-bit
Fast Ram all the way up to 128mb.

It's fun to tweak and upgrade Amiga's, especially if you have a specific task for it in
mind. IF you're looking to play the occasional game, you're likely not going to need to
soup her up too much. All depends on what you want to do with her.

Since you mentioned something about a slightly flaky power supply, I'd start with that
first. Either have it repaired or find another one. Chances are, the one you find later
will need servicing too anyway.

Accelerating your Amiga can be frustrating as hell for a myriad of reasons. You've
been warned. Find out what you'd like to do with this machine and we can further
advise you on what to do, where to go, etc.

Plus it will cost you an absolute fortune to upgrade

[Huxley_D]

Hi Save2600,

Thanks for the awesome info!  Here are a few notes, mostly based on your tips:

There is a sticker near the rear of my A2000's mobo that reads "REV 6.2" which seems a good indication that it's a later-revision motherboard.  Also, the etched text near the front of the motherboard says "REV 6" - I missed this on my initial look-over due to the thick coating of dust on the board itself!

I just removed the "BOOT" jumper on the GVP drive board and fired the system up - the boot screen is displaying a neat animation of a floppy going into the drive, and the text "2.0 ROMS (37.175)" - I assume this means I have Kickstart 2.0?  I just ordered a KS 3.1 ROM chip on eBay, but it'll be a while before it gets here.

The power supply in this machine seems to be working fine.  The flakiness I referred to was almost certainly due to the lightning storm that was causing my power to bounce up and down while I was first tinkering with it.  It's run fine several times since then.

If you can possibly provide another bit of info, I could use a bit more help:  The only Commodore-friendly monitor I have at the moment is a 1902A.  I'm connecting the mono video out on the A2000 to the RCA-style input on the 1902A.  With this configuration I'm able to use the A2000, but only in black-and-white (or is it greyscale?), which is clearly not ideal.  Is it possible to get full color from the A2000 to this screen (most likely with a different type of cable), or should I just start looking for a 1080 or 1084?

Thanks again - this is proving to be a really fun project!

Huxley

PS  I'm in Albuquerque, NM USA, and my Amiga has a sticker in the inside-rear that reads "WEST CHESTER BURN-IN" - is this an indication of where my A2000 was born?

[save2600]

Oh cool, 6.2 - so you have one of the latest mobo's they released. Glad to hear your power supply is probably fine then. Almost forgot one of the most important tidbits: when you go to install the new Kickstart ROM, be sure to examine the battery!! These almost always are bad and leak their acid near vital circuitry. Remove it if it hasn't been removed already and replace it with one of DJBase's lithium battery kit. Replacing the battery isn't just good advice: it's absolutely necessary!

Oh - and ALL A2000's only output B/W through their composite outputs. You'd need an A520 adapter if you want to use the 1902 with it, but of course, you're better off going RGB with a 1080, 1084, etc.

Indivision has board coming out for A500's and A2000's that will allow you to use modern VGA CRT and LCD monitors. Great investment for sure and would alleviate the need to track down an old Commodore Amiga monitor.

West Chester burn-in indicates where the final testing was done. "Burn-in" is a phrase used to show that the components received several hours of what is supposed to be scrupulous testing; to ensure reliability.

BTW: if you haven't done it already - go ahead and clean out the dust on your motherboard! That'll help keep the old girl cool so she'll last longer  :-)  Some people swear by those silly air cans. First off, they contain moisture and moisture leads to oxidation. Second, they only merely blow the dust around. Where do people think it magically settles? Best method for getting dust off motherboards and electronics is to get a brush with long bristles (use camel hair if you're that worried about static electricity - it's a horrible conductor) and a vacuum cleaner. Brush the dust off the components, the board itself and anything else that looks caked with dust into the hose of the vacuum and voila! you'll end up with a much cleaner computer than if you were just to have used compressed air.

[marcfrick2112]

Huxley_D: You mentioned a lightning storm causing the power probs. I Highly recommend
 getting a a high-quality surge supressor for your 2000 (like a Tripp Lite) Our miggies are getting on in age, and are pretty expensive to repair/replace, so better safe than sorry....

A recent storm pretty much killed my PC (basic IBM surge supressor) but my 1200T was unscathed (Tripp Lite Isobar Tel 6 ultra)

save2600:  Didn't know that camel hair is a bad conductor...  Wow, 'every day's a school day' as they say.....

[Huxley_D]

Just a minor update, but a cool one nonetheless:  I just stopped by the shop of the person I bought my A2000 from, and they actually had another A2000 for me!  This "new" A2000 is in pretty poor cosmetic shape (far worse than the first one I bought), but it could prove to be a valuable source of replacement parts over the decades to come.  I haven't had a chance to pop it open and see what's inside, but from looking through a gap in the rear of the unit there appears to be at least one (possibly two) expansion boards in there.

It's currently sitting in my trunk, but once I'm home tonight I'll take a close look inside and see what I might find!

Huxley

[save2600]

It's currently sitting in my trunk, but once I'm home tonight I'll take a close look inside and see what I might find!

Huxley

How exciting for you! Opening up *ANY* Amiga can garner some interesting finds. Here's to an 060 card lurking inside   :-)   lol

@marcfrick2112... yes, camel hair brushes are well known and used in the audiophile community as an LP duster. I've got one or two in fact, super soft stuff and never spits at you!

Hmm... I wonder how tarantula hair would fare...  LOL!

[Nostalgiac]

just a small bit to add to the good news:

If your A2000 had the Kickstart 2.0 from "birth", then you likely have an ECS equiped one (think of it like an A2000+ .. same as A500+) - not earth-shattering, but you would have the "super-hires" Denise and the Agnus ready for 2Mb chip memory

I have the Amax thing you have - as long as it has the 512mb roms onboard, it can run upto System 7.5 :-)

Tom UK

[Huxley_D]

just a small bit to add to the good news:

If your A2000 had the Kickstart 2.0 from "birth", then you likely have an ECS equiped one (think of it like an A2000+ .. same as A500+) - not earth-shattering, but you would have the "super-hires" Denise and the Agnus ready for 2Mb chip memory.

Tom UK

That's quite interesting!  Is there any way to tell if it's an ECS model other than the factory ROM?  Is there something on the motherboard itself that would give it away?

Huxley

[Nostalgiac]

as Save2600 already said, go and get Sysinfo from Aminet.net

Will tell you all this and more :-)

Tom UK

[save2600]

as Save2600 already said, go and get Sysinfo from Aminet.net

Will tell you all this and more :-)

Tom UK

But if you're not able to get stuff off the net and into your Miggy, than just look at the Denise chip and see if it has the part #8373. The code names of the custom chips are screened onto the motherboard. Denise is over by the video slot under the power supply...

@Nostalgic, I think you meant to say the 6.2 mobo's came with the 1mb Agnus(8372A). It was the 3000 that came with the 8372AB - that allowed 2mb Chip. I had to get an 8375 Agnus and the 1mb adapter board in order to get 2mb chip ram on my 6.2 rev, mobo. My 6.2 A2000 just had a 1mb 8372A in it originally, but yes, it did have SuperDenise... whee!  lol

[Huxley_D]

How exciting for you! Opening up *ANY* Amiga can garner some interesting finds. Here's to an 060 card lurking inside   :-)   lol

Well, I just opened up the second A2000, and it's an interesting box.  It's been pretty completely gutted - it's a case, mobo and 2MB RAM card.  No PSU, no drives, heck, no drive bracket.  On the other hand, the battery has minimal leaking (no visible damage), it's a REV 3.9 motherboard (which might make it a pre-production model?), and it has an interesting Buster Tower which my REV 6.2 machine lacks.

All-in-all a nice find, and for the $10 I paid for it, I'm happy to have some spare parts for my "main" A2000.

One additional question - would there be any reason not to use both of the 2 meg RAM cards in my main A2000?  Would they conflict, or would I just have 4 megs of usable RAM?

Thanks for all the insights, guys!

Huxley

[Matt_H]

Rev 3.9? That one's pretty uncommon. Makes sense, though - you said the guy you got it from used to be a dealer?

Check out info on board revisions from each of the hardware databases.

[Huxley_D]

Rev 3.9? That one's pretty uncommon. Makes sense, though - you said the guy you got it from used to be a dealer?

Check out info on board revisions from each of the hardware databases.

The guy I bought both systems from is a local electronics recycler - a great guy, but his specialty is tearing stuff apart, not restoring vintage gear!  I don't know anything about the original owners of these Amigas (I'm assuming they're from the same person, but I'll probably never know for sure), but they clearly had an interest in audio recording, as the "main" system not only came with a simple 2-channel mixer, but has quite a bit of audio software on the hard drive.

Huxley