Eprom chip questions. Nes snes repros.

[icemanxp300]

Ok I have ordered a bunch of stuff to start making nes and snes repros. I have done a lot of reading and was wondering if someone could explain some of these numbers to me on eproms.

 

I have read that 27c are what you need for nes. Nes is 28 pins. Wondering if a chip such as these would work.

 

AMD AM27C128-200DC

AMD AM27C256-200DI

 

AMD AM is manufatcurer

 

27 "I will assume series"

c= cmos = Complimentary Metal Oxide Semiconductor

128 or 256 is the size

200 is the speed. This is the maximum delay time between the inputting of an address and the outputting of the data to the ports of the memory chips

 

Whats really confusing me is the DC DI stuff at ends, do these matter?

 

So two chips are needed one for the prg and one for the chr. Some are 128 some are 256. I read you can use a 256 for 128 but file has to be duplicated to fill the chip.

 

Basically I read nes should be at least 150 on the speed.

 

So too sum it up will these work for nes repros? What are best speeds and what are the DC DI at ends mean?

 

I have not looked into snes chips yet.

[icemanxp300]

Apparently the DC and DI are temperature ranges.

 

 

Hmmm is appears the higher the number on speed the slower the chip...

 

maybe I should go with 150 speed not 200

Edited May 8, 2015 by icemanxp300

[Osgeld]

yes DC is commercial and DI is industrial, the latter is certified to handle more extreme temperatures otherwise the same

 

and yes the lower the number the faster the chip, if you need to go faster or not I am unsure

[82atari5200]

Those won't work. 27c128 is only 16k and 27c256 is 32k. What you need are 27c010 128k or 27c020 256k to make Ned reproductions. You need larger ones 27c1001? I think is a 1 megabit chip for snes. The ones you have are only good for Atari reproductions.

[Derek Andrews]

Hmmm is appears the higher the number on speed the slower the chip...

 

A bit late replying on this, but yes, and for the record:

 

The 'speed' of these memory chips is usually quoted as an access time. A -150 signifies a memory device whose contents can be accessed in 150ns. A -200 takes 200ns for the data output to be valid.

 

Conversely, microprocessors are specified to work at a particular clock rate, for example the Z80 ran with a clock rate of 2.5 MHz, the Z80A runs at 4MHz, the Z80B at 6MHz.

Edited August 24, 2018 by Derek Andrews

[icemanxp300]

Those won't work. 27c128 is only 16k and 27c256 is 32k.

 

Well a 256 can be used for games such as Stadium Events.

 

Plus this topic is 3 years old lol, just a little late to the party.