Re: cbm 8032 motherboard + 4164

I have the ieee-488 tester from tynemouth software

at power up all led are on  except 'REN'  and 'D3'
replacing the 6520 by a bulgarian 6821 [CM602] has the same effect, 
apparently the problem comes from a mc3446

I dont remember the use of the 'REN' line...

btw with a bulagarian 6502  [CM630P] the commodore works ....

then memory seems stable  (not yet fully tested..., I guess I'll have to 
wait the mc3446)







On 06/10/2016 23:25, Ethan Dicks wrote:
> On Thu, Oct 6, 2016 at 4:08 PM, didier derny <didier@aida.org> wrote:
>> I tried the following thing:
>>
>> removed -5v
>> removed +12v and send 5v on +12v
>> removed 4116
>> installed sockets
>> installed 4164
>>
>> works!!!
> Superb!
>
>> just need to restore +9v unregulated  (apparently only used or tape motor)
> Right (I do happen to use my tape drive - I was reading tapes last night)
>
>> IEEE-488 still not working  (pia cold, look strange)
> I have substituted a 6821 for the 6520 PIA and it seems to work fine.
> The 6821 is not hard to find (especially at my house since I worked
> for a place that had a product that included a 6821 and I got all the
> old stock when they closed).
>
>> everything is reversible... (no definitive modifications)
> Even better.
>
> Cheers,
>
> -ethan
>
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