64K RAM chips. Is the Atari designation CO60612 just ant 64Kx1?

[ACML]

Atari's own part number for 64K DRAMs is CO60612, but not many machines actually have the CO60612 on the dips. I've seen all types of OEM names like 4164, 4264, 4564, etc. What specs are required to be used in an XL/XE? I'm wanting to buy spares. I ordered some CO60612s from Best and Brad send Mitsubishi 4164s. I'm sure they will work, but just want to know what the requirements are or what specs to avoid when selecting a 64K x 1 DRAM.

Edited January 16, 2018 by ACML

[Rybags]

Ensure they're DIPs and not later type such as PLCC or TSOP. When these chips were popular was during the transition where they were moving to more compact form factors.

 

Fairly sure all the DIPs are +5V but double-check it's not lower to be sure.

 

By the time 64Kx1 was around the latency would have been well within what Atari requires. It's usually denoted in the chip suffix, in common use seems to be 9-15 which equates to 90-150ns. Supposedly Atari can still work with DRams up to 250ns (that equates to just under half a machine cycle)

[Level42]

4164 RAM equivalents:

 

HM4864(A) (Hitachi)

µPD4164 (NEC)

M5K4164 (Mitsubishi)

MK4564 (Mostek)

MSM3764 (OKI)

MN4164 (Matsushita)

KM4164B-15 (Samsung)

HYB4164 (Siemens)

LH2164 (Sharp)

TMM4164(A) (Toshiba)

TMS4164 (Texas Instruments)

MB8264(A) (Fujitsu)

MT4264 (Micron) (DO NOT BUY)

MHB4164 (TESLA)

KR565RU5 (Russian)

[ACML]

Supposedly Atari can still work with DRams up to 250ns (that equates to just under half a machine cycle)

I had two 1200XL's that came with 300ns RAM. Two different manufacturers, but 300ns none the less.

[Rybags]

Strange, I'd have thought it wouldn't work well. Though the numbers just mean they're guaranteed to work under that latency so in reality might be somewhat less.