1 megabit x 4 DRAM chips for SupraDrive 500xp - where to get them?

[Frimann]

I'm very interested

[Zetr0]

then prepare to be more interested I have found a source of 256k video chips for sale

$1.90 each, no minimum order, delivery $5

heres a linkie http://www.futurlec.com/ICRAM.shtml

Part No.
514256

Description
514256 256k Video RAM

I have emailed the sales team, asking for comfirmation of the package type, as i could only find 20pin and Zip based formats.. (20pin being the ones you want )

heres a datasheet

hope it helps

I will keep looking in my supplies fingers crossed

[Frimann]

Fantastic! That's helping the matter along

[Zetr0]

just got an email back from sales@futurlec.com

Originally Posted by sales@futurlec.com

Dear Sir,

Thanks for your enquiry and these are 20 pin DIP parts. You can order these
parts directly on our website at www.futurlec.com


Best Regards
Alan
Sales Manager
Futurlec
http://www.futurlec.com

SWEET!

sooo 16 of these chips will be $30.40 + $5 shipping (around £17.50 for a full 8MB) whooo bonus!

[Frimann]

That just rocks! But how is that 8mb? 16x256kb amounts to 4096kb in total?

It almost sounds to easy, thinking of the trouble getting hold of old 512kb expansions and desoldering the chips! All good fun though =D

[DoogUK]

The DIP RAM used for 2 meg, 4 meg and 8 meg configurations must be 1 megabit x 4 DRAM (DIP) chips, 120ns or faster. FOr 2 megabytes you'll need 4 chips; for 4 megabytes, you'll need 8 chips, and for 8 megabytes you'll need 16 chips.


Taken from the big book of amiga hardware

my supradrivexp has 4 chips in amounting to 2 mb.

[Zetr0]

5124256

262,144 words: 4 bits per word,

so applying them in groups of 4, each would only provide 0.5mb.

8 of them would be 1MB, 16 would only be 2MB so what you need is different chips. sorry to get ones hopes up...

hmmmm.... the xx4512xx would give you 4MB, what other chips did you plug in... could i have some pics

[Frimann]

@DoogUK

Where did you get these chips?

[Zetr0]

@Doug

could you take a pic of the chips so i can read their designation and ID

[DoogUK]

@Zetro.....i will do

The supradrive already had the 2 meg in when i aquired it.

[Frimann]

@DoogUK

How's your 500xp? I'm rapidly using faith in mine, as the three hard drives I've tested in it runs very unstable at best. They are all low power and should run on the A500's PSU no problem =/

[DoogUK]

I have to say it's flawless even with the a500 heavy supply.

[chiark]

I got 1mb x 4 chips off ebay... They come up quite often, however mine came from germany.

[Frimann]

Hmm... wonder what I'm doing wrong xP

When I install wb3.1 and move around some files it will eventually output a software failure which persists when i reboot. The problems got really ugly after I messed around with Amiga Explorer which kept loosing connectivity with the A500. I'm sure it was not the null modem cable, as my A600, with the exact same setup, runs smoothly with both cable and Amiga Explorer. I blame the 500XP for lack of better xD

[Toni Wilen]

Originally Posted by DoogUK

I have to say it's flawless even with the a500 heavy supply.

"Heavy" A500-style PS can be 2.5amps (not good) or 4.5amps. (two models)
"Light" A500-style PS is 4.5amps. (5v)

[Frimann]

Mine is 4.5amps so I doubt the PSU is the problem =/

[DoogUK]

have you tried using the later installation disks?
As i'm aware the original ones were buggy with 3.1.

The later ones can be found on amiga resource.

@Chiark, glad you got some 1mx4 chips..you can further upgrade it.

[Zetr0]

if some one could read me the chips serial i can begging hunting for a source 1m4 chips

[Frimann]

@Zetr0

That would be awsome. With 8 ram this box has a lot of potential if you ask me.

@DoogUK

I bought my version from Vesalia Computers a couple of weeks ago, but I guess it's definitely worth a try =)

Any of you have any experience with the green alien version?

[DoogUK]

Have a gander at this http://www.amiga-stuff.com/hardware/1mx4-dram.html.