EII Rev board 1.0 "Can´t communicate with Apple Mac SD"

[xmota]

EII Nr.1 (fully working machine)

- Logic Board Rev 1.0 (scanner 3.1, main EPROM 2.1. OS 3.1, 5,25 and 3,5 floppy drives),
- no piggy boards inside
- bought second hand, never worked with Apple
- I have 2 Macs (SE 4MbRAM, SE1/40 1 Mb RAM), neither of them communicate with this EII (tried both ports modem, printer)
- Apple has activated Apple Talk
- Both Macs tested in EII panel mode (the answer is still the same "I can not communicate with EII, check the cable and current preset has MIDI on")
- Cable is bought from a guy from Emulator forum at yahoo, cable tested, there is no problem
- MIDI is on
- all adjustments as described in the SD troubleshooting guide for boards rev 1.0 done (with no results)
- I tried to switch the EII "Under control of Macintosh" manually in the Catalogue menu, still no result

[dr.c]

Already answered as well. Try with a lower vesion software, this "rings a bell" to me...
I may be wrong, but...

Please, give me the name of the connector : CN...

[xmota]

lower OS version?

[dr.c]

Try with I don't know wich version, I forgot, its 25 years ago !!!!   

Wich OS do you use, tight now ?

[xmota]

Good news

The Emulator has been probably "downgraded" by the previous user to RS232. Do not ask me why

- R48 was cut and removed (now there is back 10 kOhm resistor)
- IC132 pins 8,9 cut 10 lifted (now there is a new IS132)

It worked like RS232. Now it is again RS422.

Now it works with SD, but the communication is rather instable. It works every three attempts. (with OS 3.1)

There is still the adjustment for OS lower than 2.3 ("If you do not have AT LEAST VERSION 2.3 of Emulator II OS software, then the following mod must be performed: Lift pin 22 of IC107 and solder one end of a 1Kohm 1/4watt 5% resistor to it. Solder the other end of the resistor to +5 volts DC anywhere nearby.")

May this cause the communication instability?

[dr.c]

F... forum... took me half hour to answer, and then, everything went away. 

Very GOOD job ! CONGRATULATIONS !  Happy for you !

Instability :

a) - How long is the cable ?
b) - Is it referenced to the OV but NOT to the ground ? (This is how it should be)
c) - Is it a professional data cable (for computer, for example) ? Don't use transformed MIDI cable, neither telephone, or dildo power supply cable, use twisted pair shielded cable !
d) - Are the connectors of excellent quality, NASA kinda ?

[xmota]

  sorry, my friend in the service spent six hours to make it work. He does not have a schematics for the Rev 1.0 so he had to use the scheme for the Rev 0.1 RS422 piggiboard. Nice

a) cable is 2 meters
b) I have to ask my friend
c) yes it is professional cable
d) well, they are normal computer connectors

[dr.c]

Question B : it is very tempting to solder the OV of the twisted pair as well to the case of the connector.

If this has been done, take this connection away.

[xmota]

No it is not soldered to the connector, anyway the data cable was probably too close to the power cable of my Yamaha CS50 on the lower keyboard stand. I put the cable away from all power cables and monitor cable, including those on Mac and it seems like there is not a problem anymore

Thanks Dr.C for help

[dr.c]

Geeeee.... sensitive at that point ?

Well, happy it works !

Gotta a second one to fix now ?

[xmota]

Well I would like to fix the second one now, but it is not too urgent now

[dr.c]

Come on !!!!

[xmota]

OK OK OK 

I will sleep better when both EIIs are working ... and I can sell one to have some money for rack EIII ...

[dr.c]

"and I can sell one to have some money for rack EIII ..."

(and get on my back because it won't be working...)   

[xmota]

hope not If it finally works, I would test it carefully before selling.