Convert EII to EII +

[JMP]

Just been reading this with interest as bought an EII with add memory board fitted but can't access the second memory bank.



Did you clarify that OS 3.1 is needed? I only have OS 2.3 currently and getting system crash when trying to access using double tap 00. Thanks.

[dfiorucci]

Hi JMP,
The ones with the piggyback memory board are actually the regular EII.
They did this because the drams at the time that were readily available were 64K so they needed 64 of them to be able to have one bank of memory.
Later on when they were able to get the 256K drams they eliminated the extra piggyback memory board since they were able to get twice the memory with just 32 of the 256K drams.

Yours is a Rev 1 digital board also so once I get this figured out you should be able to convert yours to a EII + also.

I'm waiting on my new 256K drams and the two CD74HCT138E to arrive to test this theory.

I'm guessing by the configuration of yours that it is a high 11XX or a low 12XX serial number.

[dfiorucci]

Can you let me know what chip numbers you have at IC and IC98 on the digital board?
Thanks,
Dana

[Electro disco club]

Hey guys, and girls!

Inventaire received the Texas DRAM. I hope testing that this week-end while babies sleep!

Greats

[Electro disco club]

 i.ve received the memory, pull out the memory expansion Board and replaced the 32dram on digital Board.
Before to put new DRAM, i made the switch position for 256k.

At power up hxc loads only 3 steps and the system bug, EII screen stay with *emulatorII* boot in progress.

I've tried to power up EII with 1 DRAM pull out, and the strange thing IS that hxc load the bank and i could play ( i didn't try to find if some sounds were missing).

So there isn't problem with the new DRAM.
I've got the main 2.1 chipset and scanner rom i don't know.

[Electro disco club]

Does somebody Can burn eeprom with the EII+ main rom? I saw this file on the yahoogroup?

[AlphaC]

Hi
You probably know this, but you can find it on ebay. I just bought a kit with the latest ROM, SCANNER and DIAGNOSTIC chips.

AlphaC

[Electro disco club]

Great , you're right. Does it working for EII +. I've got the main 2.1 for EII .

[AlphaC]

The seller I used is  ktracker_rus just tell him you have a EMU II+ 

[Electro disco club]

Thanks,
You 're right, i have To find some eeprom services.
I've read on older post that people who wanted to downgrade EII + HD to EII+ had used special main 2.1 EII + or main 2.3.
There are on emulator group. Great Guy who do that.

[dfiorucci]

ktracker rus was the one I bought mine from on ebay he told me that the rom for an EII and EII+ where the same.
That said I wonder if there was some confusion since he had already sold me a set for a regular EII.
I was pretty clear though that I wanted to buy another set for an EII+.
I did however compare the two files for the Main 2.1 that is labeled for an EII+ and the Main 2.1 that is labeled for a regular EII from the files area and they where identical files.
I used Text Pad which I use for writing programming it has a nice feature that it compares two files to see if they are identical.

[dfiorucci]

My new chips are suppose to be here next Thursday should be able to try them out next weekend.
If anyone has success at this let us know and the steps you did to get it to work.
Thanks,
Dana

[AlphaC]

Maybe he needed the information just for the label 

[JMP]

Hi JMP,
The ones with the piggyback memory board are actually the regular EII.
They did this because the drams at the time that were readily available were 64K so they needed 64 of them to be able to have one bank of memory.
Later on when they were able to get the 256K drams they eliminated the extra piggyback memory board since they were able to get twice the memory with just 32 of the 256K drams.

Yours is a Rev 1 digital board also so once I get this figured out you should be able to convert yours to a EII + also.

I'm waiting on my new 256K drams and the two CD74HCT138E to arrive to test this theory.

I'm guessing by the configuration of yours that it is a high 11XX or a low 12XX serial number.

Ah thank you, that solves it. I had initially been told it was additional memory making it an EII+ but I see now it isn't. Good luck with your resolve. Cheers.

[dfiorucci]

When I pull IC98 to swap it with the brand new CD74HCT138E I noticed that the original had the last leg bent under so it wasn't making contact.
Can anyone with a working EII+ verify that the last leg of IC98 needs to be bent under.

Installed the new IC and dram still no total joy while the memory test good I'm getting a consistent static in longer samples.
I'm guessing the ram is not being address correctly but it's a mystery to me what needs to be changed.