What A500 do I have?

[Protek]

I've been wondering my A500 ever since I installed an 2.05 ROM into it. With the trapdoor mem expansion in place, the WB says that it has 1 MB of Chip and 0 other. I thought this was a glitch in WB but the hw info in tools says that the A500 has ECS PAL Agnus and normal Denise. The Agnus chip is 8372A and on the mobo it has 512K/1M printed and there are empty places for memory chips on it. Is this a late revision A500 just prior to A500+?

[Protek]

edit -- I've heard mention of some very late A500's actually having A500+ rev 8A motherboards (possibly C= refurbs?), though that would definitely not be common.

According to BBOAH, the A500 that are badged "A500" instead of "C=", should be rev 8A. There was one for auction at the local auction site.

[Protek]

darksun9210 wrote:

sounds like you have a 1meg agnus as these report back as ECS chips and the jumper/cut fix to mark the trapdoor memory as chip ram.

have you have the machine from new, or is it 2nd hand? if it is 2nd hand, i'd suspect the jumper/fix trick.

It's a second hand machine, picked from a local recycling center. Where the jumper or trace cut can be located?

So, it's either 1 Meg chip or 512/512 chip/slow, right? No possibility for 1 Meg chip/512 slow?

This is an interesting machine. At first I wasn't able to get a picture to it even though it was clearly booting. Swapping the CIA's or more likely re-seating the CIA's seemed to help. Still need to find a working keyboard, since the right "Amiga" button isn't working. Can't arrange icons or make soft reset. Might have to look for an fast mem expansion for it. I have IDE68K HD adapter with a 1 GB CF card installed, so doesn't really make sense to get a SCSI controller with memory. I was positively surprised that the whole 1GB was available with revision 37.300 of the 2.05 ROM.

Edit: Would the rev 6A mobo be a good basis for fully ECS compliant A500, basically A500+? If you change the 8372A to 8375 Super Agnus, Denise to Super Denise and add the missing memory chips, would you then basically have an A500+, with possibility to use 1MB expansions?

[Protek]

Thanks for the info! Have to endure the side expansion ram option at some point. Memory expansion for A2000 has higher priority ATM.