Emax

Ah, Ok I guess I've been sniffing too much glue...my head is spinning.

So to be clear, the EPROM programming conversation is only for people who have acquired an expansion board but not the floppy that went along with it, or their unit is not recognizing the memory they already have.

To reverse engineer an expansion board we would have to also program a few PALS as well!

It certainly sounds close to impossible given the groups resources.  If only EMU would be more helpful...

But I'm going to keep probing, so I have another Frankenstein question:

Even though the PCB is 4 layer, would there be a way to reproduce the schematic on say 2 different breadboards connected by jumper wires that would be at least electrically compatible?  Or is one of the chips necessary for the expansion board some kind of TSOP or SMT package?  I am just saying that there is certainly enough room in the EMAX to spread out the components more than the original 4 layer PCB, or to stack them up using additional standoffs.  It wouldn't be the prettiest thing, but if at least it worked...

I found this website that shows a picture of an AZF memory module that looks quite similar to one piece of the puzzle that could be used...

http://www.memoryten.com/pc/003180/FPM-20p-1Mbit/

And they are having $1 shipping so the whole cost is $3.49!!!!

So the breadboard would hold all the non-memory components, and then that board would be jumpered into the AZF board above...

Could someone list the other full chip labels so I can start looking them up on chipdocs.com?  At least I can dream...now where's that glue?

74HCxxx???




--- In emax@yahoogroups.com, "jammie" <jammie.emma@...> wrote:
>
> if some one is willing to donner there board then duplicating it is not a problem x ray scanning the board and using the scan in eagle is possible as we have done it for asr10 sp3 scsi interface which is a 4 layer board and the production costs for resale worked out at £120 which is cheap as the original was £300 from ensoniq
> 
> it can be done and you can use a logic scanner for the functions of the pals its not impossible and thats how manufacturers upgrade there boards with new tech for old industrial computers
> 
> it would be nice if we could get the bin files for the pals we would have to ask rob if he could find out if the bin files are still available 
>   ----- Original Message ----- 
>   From: dwv1957 
>   To: emax@yahoogroups.com 
>   Sent: Tuesday, December 01, 2009 4:38 AM
>   Subject: [emax] Re: Memory Upgrades
> 
> 
>     
>   You are exactly right Ted, the expansion board has 4 PALs on it plus some 74HCxxx chips on it, it is also a 4 layer board, so the amount of work it would take to duplicate it is just not worth it.
>   As for "stacking" chips on the motherboard's 18 pin sockets, not a hope in hell of that working (sorry).
>   The only way to upgrade the Emax2, is to have the original upgrade board, as long as you have that, you can upgrade it to anything you want.
> 
>   Dave
> 
>   --- In emax@yahoogroups.com, Ted Summers <djtbs1@> wrote:
>   >
>   > My understanding is that the RAM expansion board has PALs that go with it.
>   > Getting the PAL binaries for the SCSI update wasn't easy for Rob at Emulator
>   > Archive.
>   > Even if you duplicated the PCB, you would have to be able to make the PALs
>   > that allow the access to the extra memory.
>   > You would need the original PAL binaries for that.....
>   > 
>   > Otherwise the Emax wouldn't be able to address the additional memory....
>   > even if it was physically installed.
>   > 
>   > Someone correct me if I am wrong in my understanding of what was discussed
>   > previous on the thread.
>   > 
>   > Regards,
>   > Ted
>   > 
>   > 
>   > 
>   > 
> 
> 
> 
>   
> 
> [Non-text portions of this message have been removed]
>