Where to find ZIP RAM? Or A2386SX schematics?

[spirantho]

Talking about all these bridgeboards in the other threads makes me want to get my uber-rare 486-based A2386 working again.

But I need two things:
1) Schematics preferably. Pleeeease! It'd help SO much! You ever tried debugging a three layer PCB without them?
2) RAM chip! I need the 41464AZ08 ZIP RAM chips used for dual-porting! They're like hens teeth.

Can anyone help? Please?

[spirantho]

Unfortunately they won't be - the 41464AZ08 chips I need are 64Kbx4, so you need two of them to get 64KB. In other words, for one Megabyte you need 32 of them! Hence they're pretty unlikely to ever have been used as a general RAM expansion. If he DOES have any though, I'd be interested, for sure!

[spirantho]

Thanks, that'd be appreciated... unfortunately though there are a lot of different RAM chips in identical packages so unless they actually have 41464AZ08 written on them they won't work. But if does have some that'd be wonderful!

[spirantho]

Unfortunately these RAM chips are way too obsolete for any modern company. I don't think anyone's used ZIP RAM in about 15 years, let alone page mode 64Kx4 stuff like this!
Thanks for the suggestions, though!

[spirantho]

Nope, just the (expensive) 2386. The 2286 and I think the 2088 both have 64K RAM and use standard jobbies instead of Zip chips. I checked that first as the 2088 boards are dead cheap.

Thanks for the suggestion though - any others?

[spirantho]

Thanks for those links, I'll check them out.

I know the dual port RAM is bad because all the chips are missing a pin. It's a long story but basically I have two bridgeboards and 4 41464AZ08 chips between them. Each needs 8.

For those who don't know what a joy ZIP chips are, the pins on them are VERY brittle, hence why half of mine are missing pins. The other 4 are in my 2386 and I don't want to move them as I might break another pin (it's nearly impossible to mess around with them without nearly damaging one). If I get another 2386 it's quite likely one of the chips will lose a pin and then I'll need another one!

Hence I need 4 more so I can at least try and fix it again (it's just lying there annoying me. Wouldn't be so bad except a) I've never had it working - it got damaged in transit and b) it's so rare! When was the last time you saw a 486SLC Commodore Bridgeboard!?)

It's a kind of long term project. I fear the CBM-specific logic chips soldered to the board may be dead, but I can't be sure unless I have 4 of these wretched chips.

Thinks: MAYBE I can use standard DIL chips instead with a bunch of wires.... interesting idea but it should work...

[spirantho]

Oops, yeah, I meant each board needs _4_. Not 8!

And yes, they're in the same 20-pin ZIP package, but the main RAM and the page mode RAM used by the dual porting are quite different, unfortunately.

[spirantho]

Oh, I know where the 41464 chips should be - I was the one who desoldered them.

The board is actually a 386 board that was taken by Elite Computer Systems I think it was modified by them to take a 486SLC instead of a 386, and the clock speed was upped to 33MHz.

It's the only board I've ever seen like it.... Problem is I've spent so long with the darn board trying to make it work there's quite a few patch wires all over it now.
I think I was testing it before with the wrong kind of RAM chips, so I need to get hold of these 41464 things so I can test it properly, just in case...!

[spirantho]

Indeed, Scott Drysdale was on that group. His name is on the bridgeboard itself. Judging by his sig in the only posting I could find:
---
formerly mr. bridgeboard @ cbm.  soon to be a seaman recruit in the us navy.
---

it may be difficult to track him down now!

[spirantho]

Worth a try, but no joy - that address just bounced. Assuming I really did have to remove the "RemoveThis" bit.

[spirantho]

Looks like that's the way to go then...

I've found some DIL chips on eBay too, they may help.

Thanks again.

[spirantho]

Oo what a shameless plug, resurrecting my thread from years ago.

I did actually find the Zip chips that I needed - and I should point out that you don't have the chips I was looking for - I was looking for the MN41464AZ08 chips which are used for the dual port RAM, not the 514400 chips which you have for the main RAM.  But as most people will be looking for normal RAM, not dual port RAM, your plug is allowed.

Never did get that bloomin' bridgeboard working. Real shame, given it's one of the very few 486SLC-based A2386SXs....