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MPM-293 Cassette Interface Schematic


ekeefe8051
 

Hello,
 
As promised, here is a link to a scan of the CDP18S652 cassette interface schematic from the MPM-293 manual.
 
 
ED


thinkpast
 

Thank you, Ed. I have this board as unpopulated. Also, I'll add it to the documents I've accumulated for the development system I worked on, as shown on my Web site. With the UT62 monitor source and the cassette interface it controls, that completes documenting the monitor. - regards, Herb Johnson


cellarcat
 

I have this board unpopulated as well. Interesting note - the parts list makes no mention of what transistors are being used.

On Jul 26, 2020, at 4:59 PM, ekeefe8051 via groups.io <ekeefe8051@...> wrote:

Hello,
 
As promised, here is a link to a scan of the CDP18S652 cassette interface schematic from the MPM-293 manual.
 
 
ED


Doug Jackson
 

Yes,

That is odd.

Given the era, and the switching nature of the transistors, I would suggest something like a BC548, or 2n2222. 

Kindest regards,

Doug Jackson

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Check out my awesome clocks at www.dougswordclocks.com
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On Fri, Jul 31, 2020 at 10:03 AM cellarcat <petelco@...> wrote:
I have this board unpopulated as well. Interesting note - the parts list makes no mention of what transistors are being used.

On Jul 26, 2020, at 4:59 PM, ekeefe8051 via groups.io <ekeefe8051@...> wrote:

Hello,
 
As promised, here is a link to a scan of the CDP18S652 cassette interface schematic from the MPM-293 manual.
 
 
ED


ekeefe8051
 

Hello,
 
@thinkpast
 
You're welcome.
 
ED
 


ekeefe8051
 

Hello,
 
@cellarcat
I have the actual board along with the one I recreated.
 
The 4 transistors are 2N2222 in metal cans.
 
ED


cellarcat
 

Thanks, Ed! That fills in the gap.

On Jul 31, 2020, at 6:37 AM, ekeefe8051 via groups.io <ekeefe8051@...> wrote:

Hello,
 
@cellarcat
I have the actual board along with the one I recreated.
 
The 4 transistors are 2N2222 in metal cans.
 
ED