2mb chip ram on A500+

[desantii]

Just finished adding an extra 1mb chip ram to my A500+ (rev 8.1), used 8 more 256k x 4 DRAMs on top of the existing ones.
It was fairly simple (doesn’t look pretty but it works). Bend pin 17 on all 8 new chips. The leftmost 4 are then all connected via pin 17 and then connected to pin 36 on the memory expansion connector. The other 4 again all connected via pin 17 but to pin 35 on the memory expansion connector.

This gives an extra 1mb chip ram for a total of 2mb
I will post pictures tomorrow, but for now extremely happy with 2mb chip ram, now I need some type of accelerator J

[walkero]

I was looking for memory chips to do this hack myself, but I didn't manage to find them. Can you tell me where you found them? Do you have any extra chips for sale? Did you do any memory tests on that?

[Zac67]

514256 chips can be salvaged from tons of old machines - mainboards, VGA cards, printers, ...

[brownb2]

Just finished adding an extra 1mb chip ram to my A500+ (rev 8.1), used 8 more 256k x 4 DRAMs on top of the existing ones.

This may seem a stupid question but if it was an A500 Plus why didn't you just upgrade the chip ram via a trapdoor expansion?

As an aside, I miss my A500 Plus (2MB), it kicked 640k 286 8/12mhz bum.

[desantii]

I had some salvage chips I used(sorry no more chips). I did it as I had the chips and the 1mb expansions are not that easy to get a hold off.

[desantii]

Bad news, after a couple of hours the sceen went corrupt, then after reboot it would only see 1mb.. of course after they were soldered in places... now for some debuging

[Ni72ous]

Any news on your problem? Did you get it working again?

[desantii]

Hi, actually yes. One chip had a cable that was not properly soldered, its working again.

[560SL]

Good hacking! The A500+ is a nice old lady. Certainly deserves a full 2Mb chip ram expansion and some fastmem.

I remember I had to search a good while before finding a trapdoor expansion.

As for accelerator, even a cheap Supra Turbo (68000/28Mhz) will give it a good kick.

[desantii]

Actually the Supra is next on the list for my 500+

Good hacking! The A500+ is a nice old lady. Certainly deserves a full 2Mb chip ram expansion and some fastmem.

I remember I had to search a good while before finding a trapdoor expansion.

As for accelerator, even a cheap Supra Turbo (68000/28Mhz) will give it a good kick.

[Ni72ous]

Hi, actually yes. One chip had a cable that was not properly soldered, its working again.

Good to hear, did you get round to taking pictures?, would like to see them if you did as i plan to do the same mod on my A500+ too.

[560SL]

Good to hear, did you get round to taking pictures?, would like to see them if you did as i plan to do the same mod on my A500+ too.

Yes! Pics or it didn't happen!

[Jeff]

Great project!  I remember doing a 2 meg chip mod on a rev 6.x A500 many years ago. It used an A3000 Agnus and 1 meg x 4 drams.  I think it was in Amazing Computing Mag late '93.