Monthly Archives: August 2010

A3000 memory problem solved

I have had problems with A3000 memory. When I bought it as used several years ago it had ZIP type chips added to motherboard. Then these started to loose and popped out twice per year. Finally I get enough for playing and removed ZIP:s and moved 1MB of chip DIP:s to fast memory side. 1MB chip and 1MB fast is not much. My A3000 have still so called 1.4 ROM which reads rom from disk to fast memory. ROM takes half megabytes of memory. A3000 project went to the ice for several months, because I didn’t find good and cheap solution to add more memory.

Then one day I found used GVP 4000 HC+8 SCSI Zorro board with 4MB of fast memory. Solution worked but I think it is stupid to have two SCSI-controllers in so small box. Another problem is to find suitable memory to GVP. 5MB fast memory is not enough for everything, but machine was usable.

Finally I found perfect solution for me: ZorRAM Zorro3 memory expansion. ZorRAM is produced and sold by Amigakit. There is 128MB and 256MB versions available. ZorRAM requires Buster V11, which fixes problems with Zorro3 DMA. Amigakit sells also Buster chips. I decided to order ZorRam 128MB and of course new Buster. Delivery from UK to Finland was very fast. If I remember right order was made at Thursday and next Tuesday I had memory expansion and chip at the post office. Nice.

Installing was easy. First I opened A3000 and removed all Zorro-cards. Then was turn of the equipment platform where power is sitting. Underneath equipment platform there is for example fast memory sockets, ROM:s and Buster. I removed old Buster carefully from socked without proper tools (with small screwdriver). Replace old one with new and putted equipment platform back. I started to add Zorro-cards from bottom to top. First I added GVP Spectrum 28/24. Spectrum have nice pass trough to video. By the way it is very usable with A3000 internal scandoubler. Second was ZorRam and last XSurf. XSurf have IDE-controller which I use. ZorRAM is small Zorro-card, as big as Zorro-connector on daughterboard. Memory expansion had nice markings which way it should be installed. “Backside” etc. You can not fit it wrong way if you keep your eyes open.

I turned A3000 first time without cover, because every time I have tested almost anything I have had to open it again. Not now, early startup show that everything was working. Then cover back over the machine and boot. I had never used Amiga with over 64MB fast. It worked and I was happy. I haven’t had time to test speed of the memory yet. It might be little slower than memory on cpu-expansions. Anyway 030@25Mhz is not so fast anyway. At least compared to my Mac mini with MorphOS or even 1200 with 060@50Mhz.

As soon as I get 3.1 ROM:s at the same I move 1MB fast RAM back to chip side. With A3000 I have never had any other than this memory problem. It is quite nice Amiga.

Picture of ZorRAM