I found this site when I was responding to someone else, somewhere else. You see, I did a search to see if I could find my previous work from 1992, when I posted instructions how to modify an Amiga 500 rev. 6A motherboard to 2 megs of chip ram. I found
a thread here asking such a question, but nobody was right about modifying the rev 6A motherboard.
Soon after the A3000 came out, being a curious ET, I sifted through a repair manual that a dealer had for the machine. I payed special attention to the Chip memory circuitry. I popped open my A500, and compared the motherboard to a photocopy of the A3000 schematic. I then went to the Amiga dealer and ordered the 8372B Agnus. Got ahold of some 1meg x 4 DRAMs and I was set. Modified the A500, all on the motherboad, no piggyback chips. All clean and simple.
Anyway, I posted the instructions in the above link.
Have fun with anyone who dabbles with mods. Good luck finding 1meg x 4 memory... That's probably hard compared to the Agnus.
Somewhere, there is an A500 floating around modified by me with 2 megs of motherboard chip memory. Sold it in '93 or '94.
Here's one of my earlier C-64 1541 Drive mods, from maybe 1984:
On the day the A4000 was available in October 1992, I bought one. Wrote a little file that reduced the memory wait-state by one clock cycle, but I had to use 60 ns. memory to make it work. Fell into hard times and traded it for a sick A3000 and cash. Ended up desoldering the 132 pin CPU and resoldering it. Fixed the problem that way. later bought the Cybervision 64 3D card for it. I still have that computer, but haven't powered it up for some time. I've been meaning to power it up and make a monitor file of 1800 x 1200 for my 24" widscreen and see how it works. As much as I loved my Amiga experience, I don't know if I'll ever use it like I used to. I recently purchased a 2.8ghz Dual core pentium with XP professionalon it, widows 7 disks, 500GB Segates barracuda HD, and best of all... No unwanted software on it. Bought it when the old Dell Dimension 3000 I had wouldn't support 1920 x 1200 that my new monitor does.
Oh well... Gave me the excuse to but a new computer.
I have seen stuff on the new Amiga retro computers, using Ubuntu. I'll bet that's a sweet machine.
