Convert EII to EII +

[dfiorucci]

Tried bending the last leg under on IC98 to see if there was any difference same result as before.
Upgraded memory test good but ram is obviously being address wrong.
So here is a quick run down of the history of the upgrade and what I've tried.

The memory upgrade EII to EII+ pdf instructions was based on converting a Rev 0 digital board EII to an EII+
Written by Emu Systems 01/22/1984
It was last modified by Rob at the Emulator Archive on 09/18/1999
It involved cutting traces and allot of kludge wires to reroute to achieve the changes that were made to the Rev 1 digital board.

Again the goal here is to take a regular EII that already has the Rev 1 digital board ad convert it into an EII +.
The assumptions are that you should have to replace the 32 Drams on the digital board with 256K 150ns or 256K 120ns drams.
It should require Main 2.1 and Scanner 3.0 eproms and OS 3.0 or OS 3.1
If there is a difference in these eproms for a regular EII or an EII+ I haven't been able to determine any difference.
Also it is assumed that the Rev 1 digital board would not need any traces cut or kludge wires added.
So far I've been able to match pictures of EII + digital boards as far as the chips and what chips are left blank.
So the questions remain are this
Does it require OS 3.1? I've tried OS 3.0 with no success
Does it require a specific version of the Main 2.1 eprom or Scanner 3.0 eprom to support the additional bank function?
Are there any kludge wires on the bottom of a Rev 1 digital board that makes it an EII + functionallity?
Are there any required cut traces?

I'm really surprised that there wasn't a tech bulletin created on how to convert an EII with a Rev 1 digital board into an EII +.

[Electro disco club]

I think the pin bended IS to provide the Good communication with Old Macintosh.

Have you try to solder the jumper differently? Do not solder jumper as EII + photo? Start from the first 2 point EII config until  w1 & w4 like a ''V''.

??

[dfiorucci]

Yeah I have the jumpers set using a two switches that I had installed years ago to be able to switch back and forth the jumpers.
So the source wire goes to the center of the switch and one side goes to w1 and other to w2 then the other switch is wired to toggle between w3 & w4.
I verified that the connections where good with a meter.

[Electro disco club]

So ... What's next?
I'm looking for eprom and UV eraser and eprom programmer.
Approximatly 80dollars budget via eBay and aliexpress. Need just some cash.
Burn 2.1 eII + main boot or 2.3 via yahoogroup.
Downgrade works fine from EII HD+ to EII+ with the 2.3 main rom...
On eBay be careful it's a shame to read that we'll have the last O.S 3.1 with the scanner rom 3.1... Misunderstood!

The forum IS a very Big acknowledge for all this tricky crap.

[dfiorucci]

I'm thinking at this point it's a new Main 2.1
I think I was able to find a eprom burner for around $56.

[dfiorucci]

Ordered a eprom programmer and some eproms today.
Should have it by next week.
I'll let you know if it works.
If so I can probably burn you some eproms too since I ordered some extras

[justnoise]

Nice! Really looking forward to the outcome.

[Electro disco club]

It's Nice Dana that you try to make it.

You put your cash on a project without known the finality.

I don't have the Time to try and maybe knowing that you try it Can give me peace.

[dfiorucci]

Well I was able to burn the new Main Rom 2.1 from the files area that came from a working EII +
But still the same result as before.
This is using OS3.0
Anyone with a working EII+ that can send me an OS3.1 disk to check to see if I can get this working?

No joy in mudville today LOL
Thanks,
Dana
PS anyone need Eproms burned PM me I have a few extra

[Electro disco club]

Bad news.
Do you have an hxc card?
Sorry I've pull out all disk drive on m'y EII.

Did you try with the main 2.3?

I'm interested in.

[dfiorucci]

No HXC yet but I'm planning on putting one in eventually
I think Main 2.3 is for the HD version?

[Electro disco club]

They use it to downgrade HD + to a normal  EII+ model.

[dfiorucci]

After looking at the jumper settings again I may have an error in how I've wired them up.
I did that many many years ago when I installed the toggle switches.
I'm hoping that this is the problem
Stay tuned
Thanks,
Dana

[Electro disco club]

It will work.
Hope
Hope

[dfiorucci]

Well here is to hoping.
I rerouted the switches and I was still having problems.
It would click 3 times on the drive then nothing.
So in a last ditch effort I found a different Main Boot ROM bin online.
Compared the file to the one had burned previously and they were different.
So I burned the new Eprom with this bin file stuck it and booted up
Whala!!!
Great Success!!!
After 34 years I now have an Emulator II+

So again if you have a regular EII with a Rev 1 digital board it is easy to upgrade it to a EII + (Well it is now!!!)
Process
Open up EII
Remove piggyback memory board
You will need to remove jumper wires from W2 & W3
You will need to add two new jumper wires from W3 to W4 and from W1 to W2.
These will be in a vertical line to each other.
Previous jumpers are running horizontal.
Replace the 32 64k memory drams on the digital board with 32 256k memory drams.
I replaced IC11 & IC98 with new CD74HCT138E
I bent the bottom right leg underneath when replacing IC98 to match the one that I pulled.
Replaced the Main Boot Rom with one that I burned using the E2newrMain_HDMB2_3_MAIN.bin  file poste by czh90 from the Yahoo group site.

Links to the parts I used
I'd recommend ABRA Electronics as they had the DRAM the 74HCT138 plus all the stuff I needed to build a new floppy cable to get ready for the HXC update that I'm doing next.

DRAM 150ns super cheap 65 cents each
https://abra-electronics.com/ics-semiconductors/dynamic-video-rams/41256-150-16-pin-256k-x-1-150ns-dram-41256-150.html

74HCT138 35 cents each
https://abra-electronics.com/ics-semiconductors/74hct-series-dip-package/74hct138-74hct138.html

Blank Eproms
https://abra-electronics.com/ics-semiconductors/eproms/m27c64a-15f1-eprom-u-volt-64k-bit-8k-x-8-150ns-fdip-28-m27c64a-15f1.html

I used a TL886II Plus USB eprom programmer to burn my chips got it off of Amazon.

Well there it is in  a nutshell.
Post if you have any problems are need an eprom burned doing the upgrade.
Thanks,
Dana