Amiga A500 Next Steps

[clh333]

My thanks to the membership for their advice and support as I resurrected my two Amiga 500s, board Rev 5. In the process I learned a good deal about the design and manufacture of the Amiga; I also read, and recommend, the book Commodore: a company on the edge by Brian Bagnall.

Now it is time to take the next step and I would like to ask for your advice once again. There are four areas where I think hardware modification may be advisable:
1) Both boards have the original (1980s) capacitors. I have read that these are prone to failure and should be replaced. Is "pre-emptive strike" or "wait-and-see" the preferred strategy?
2) The boards have the original 68000 CPU, Gary, Paula, Denise and Fat Agnus ICs. I read that there was an "enhanced chipset released a few years after. Are they still available and is that an option for this board (Rev 5.)?
3) The operating system has come a long way from my Kickstart 1.3 ROM. I can purchase and install a v.3.x ROM, but is there a down-side to doing so?
4) There are a number of "expansion" add-ons available: One such is the ACA500 board. Amigakit lists it but it is out of stock on their US site: http://amigakit.leamancomputing.com/...oducts_id=1168. Does anyone have an opinion (now, there's a loaded question!) about this or other accelerators? *

* Depends on what you want to do, I realize. I would like faster processing speed, more memory and the ability to interface with clock hardware, IDE drive hardware and compact-flash hardware, not necessarily in that order of importance. I also would like this more capable machine to run the newer OS. Ideally I'd keep one A500 "box-stock" and tweak the other.

Thanks again for your advice.
Charles Hudson
clh333

[ajk]

1) Capacitors are not a big problem with A500s. Later models such as the A600, A1200 and A4000 used smaller surface mounted electrolytic capacitors, which are prone to leaking and drying out. You don't need to do anything about the caps on an A500 unless you encounter problems. That said, I did swap out the ones on my board while I was working on it otherwise, just to future-proof it.

2) You can upgrade at least an A500 rev 6 to the newer chips, but I am not certain about rev 5. Probably requires more work if nothing else. I'm sure someone here will know. I would not consider it a critical upgrade, though.

3) The main downside is that you lose some compatibility with older games (and some applications). Also a floppy-based 3.1 is not great, so you'd really want a hard drive and some extra RAM at the minimum. 3.1 is much more comfortable to work with, if you do "serious" stuff. For floppy-based games, it's mostly a hindrance. Depends on what you have planned to do with the setup. There is also a 3.9, which would require significant upgrades before you can run it at all.

4) An accelerated A500 is very nice, and as you have found out there are many boards to do that with. It would, however, be much easier to upgrade an A1200, and with a companion A500 you would have the best of both worlds. Just an option to consider. Here is my A500 project for some ideas.

[Viserion]

Take a look at this pdf file. It will you the information to upgrade your rev 5.

It's more fiddly than whit a rev 6a however.

A kickstart rom higher than 1.3 will not work out of the box. You ideally need to get a socket, and solder the wires that need to be soldered, and then install the new rom.

Personally I feel that os3.1 is bit too much for an A500, and would rather go for a so 2.x system that are better developed that 1.3, but easier to run that os3.1. Of course it depends on what your upgrades will be.

It is possible to run Os 2.x on a system with kickstart 3.1.

For upgrading Agnus and Denise, see link and it will give you the details on how and why.

Simplest upgrade would be Kipper2ks memory board with either 4 or 8 mb and give you the possibility to boot from a CF card. A 37.350 kickstart or higher is necessary.

If you get an ACA500 kickstart 1.3 and 3.1 is included, but you will loose 512KB memory. As it will only give you 2mb extra that's a bit too little if you wish to run WHdlead games.

You can use several of the accelerators aimed at the A1200.
Memory will then not be a problem, but the games I tried ran way to fast on a 030 ACA. But you probably know this already.

Of course there hopefully will be a Vampire 500 at some point that probably will make the A500 as fast as it can get.

[clh333]

Originally Posted by ajk

4) An accelerated A500 is very nice, and as you have found out there are many boards

Here is my A500 project for some ideas.

Thank you for your suggestions.

The A1200s that I located in a brief search today are all PAL rather than NTSC. Would that make a difference here in the US?

Your A500 project is very impressive. I consider myself accomplished if I manage not to burn myself with the soldering iron.

-CH-

[clh333]

Originally Posted by Viserion

Take a look at this pdf file. It will you the information to upgrade your rev 5.

Of course there hopefully will be a Vampire 500 at some point that probably will make the A500 as fast as it can get.

Thanks for your reply. I will look into the chip upgrades outlined in the article. The DCE Viper 520 CD referenced above was probably the best option, but no longer available.

Your reference to the Vampire led me to the Majsta.com site. Who is this person and how far along is he with his development; i.e. are there any working examples?

-CH-

[ajk]

Originally Posted by clh333

The A1200s that I located in a brief search today are all PAL rather than NTSC. Would that make a difference here in the US?

Not too much, you can switch between PAL and NTSC in software. I think it's possible to do a full conversion by changing a crystal and maybe another component or two, but this is not something I have done myself. You would need a local power supply also, of course.

[Viserion]

Originally Posted by clh333

Thanks for your reply. I will look into the chip upgrades outlined in the article. The DCE Viper 520 CD referenced above was probably the best option, but no longer available.

Your reference to the Vampire led me to the Majsta.com site. Who is this person and how far along is he with his development; i.e. are there any working examples?

-CH-

Wish I knew how far along Mahasta is.

Preorder for the Vampire 600 V2 over at Amibay. It does contain a bit of information.

ETA for it is Q3 or Q4 this year, but could be released earlier.

They are developing the Apollo core here. Nothing directly about the Vampire 500 that I could see, hastily looking trough the site.

So I hope it's ready before the Vampire 600 project is finished, or it could take a while.

[clh333]

Originally Posted by Viserion

They are developing the Apollo core here.

Knowing nothing about the Apollo core I had to research the subject and then learn what was meant by FPGA referenced there. Wow!

If I understand the implications of this technology correctly it would be like having a microprocessor that could emulate any other. The limiting factor, assuming a large enough array of gates, would be the programming.

Quite a concept. Guess I'll wait and see what develops. I got the impression that development is being supported by pre-orders. Is that correct?

-CH-

[Viserion]

It is pretty awesome that people can design something like this.

Majasta is asking prepayment as it would be too much to buy it all himself, and then get payment from the buyers afterwards.

[Zippy Zapp]

Hi. I can't say enough good things about the ACA-500. The only negative is it should have had 8MB of Ram. However I don't believe the ACA-500 works with a Rev 5 NTSC 500, I am not sure why, as these are plentiful in NTSC world. He is working on a new revision, that's why they are not in stock at AmigaKit. The new revision is supposed to work with the Rev 5 500 and have a few more features. Hopefully he releases soon as I have a Rev 5 that needs one too. Given how cheap RAM is I hope he adds more RAM too.

If you want to use your Amiga for playing floppy games, I wouldn't add 3.1 KS. You will run into many compatibility problems with many floppy games and demos. As, brought out already, the ACA-500 has an option to use 1.3 or 3.1 that are built into the device and allows you to use a CF card as an HD. It also allows you to use another CF card as a media drive with FAT to transfer files to and from the PC. You can use this to transfer ADFs and then use available software to write them back to floppy. It works great.

You didnt mention if you have it or not, but trap door RAM with clock would be an inexpensive addition to do. Or if you want even more RAM then get one of Kipper2k's modules. He sells trap door RAM too.