RAM source for A2091

[as102070]

I just received and installed 16 chips and they work in my 2000HD
they are fitted into the A2091 board.  the previous ones i removed were a mix of 80ns and 70ns (still working)

but if you need a source for 16 dram chips for this specific board, this is what i purchased (60ns chips):

MB81C4256A-60P    16    IC,DRAM,FAST PAGE,256KX4,CMOS,DIP,20PIN,PLASTIC

i sourced them from https://www.questcomp.com/

[Boing-ball]

I just received and installed 16 chips and they work in my 2000HD
they are fitted into the A2091 board.  the previous ones i removed were a mix of 80ns and 70ns (still working)

but if you need a source for 16 dram chips for this specific board, this is what i purchased (60ns chips):

MB81C4256A-60P    16    IC,DRAM,FAST PAGE,256KX4,CMOS,DIP,20PIN,PLASTIC

i sourced them from https://www.questcomp.com/

US company. Thanks for the recommendation. Will have to see how they fare with Mouser.

[RetroNinja]

I've ordered them from China a few times. Once you get them you'll need to spend a couple hours testing all of them. The last time I ordered (40) and (6) were bad. I contacted the seller and he refunded me 15%. They appear to be old pulls from DIP sockets. I did not see any old solder on the legs.

Per the manual, an A2091 supports 100ns or lower DRAM. It is better to get the 60/70ns like you mentioned since you can use them other places - specifically if you update your A500 rev6+ mobo from 512KB to 1024KB. I *think* that requires 70ns or lower.

[zipper]

I *think* the access was 150 ns  and the 0.5 MB boards tended to have 120 ns chips, up to 70 ns.

[Boing-ball]

Good to know….