sharp pocket computers - super clever trick how to do 1.27mm connector :-)

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7alken

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Aug 4, 2025, 5:58:12 PMAug 4
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hi guys, this made my day now ... playing with PC-1350 and even smaller PC-1248, hearing that tape buzzer sounds over audacity ... I found super trick how to use theirs 15pin serial connector on this japanese page, not to mention its super clever to use board also for 11pin connector where also tape interface lives (theirs school machine G850V with Z80 has only this 11pin reused for 4 things, yet another coolness...) .. uff, must share this!

btw these 11pin and 15pin connectors are something I like to reuse even more ))


all credit goes there :-)
https://ht-deko.com/pokecom/

(in process of squeezing 32bit vmex down to teaching sim on tiny 4bit PC-12xx)

btw, my own attempts to do audio interface for PC-1350 went from making simple circuit on universal board, so I also tried to do connector, and to not stress internal female connectors, rather from 1.27mm pins even for larger 11pin one ... tried also that tiny 15pin (1.27mm) - complicated soldering ya, I have bad solder paste also ... but okay, connectors done, well ...but then, being lazy, I peeked WHY the hell PC-1350 doesn't fit into CE-123P ... ya, its that locking pin ... gone ... but still its moved by probably 1mm down as top plastic guides blocks it ... gone ... but it is still 0.5mm off ... so, few minutes of manual "machining" using knife on the top plastic side to make room for that 0.5mm and voila ... PC-1350/60 fits into CE-123P too ... cassette audio interface works but printer doesn't (relay is heard/silent but its weak?), so ... will be more fun with nice service manuals, there is described everything, including schematics ... just to note, japanese are crazy ... theirs GND is in fact positive of battery, so ours Vcc ... and theirs Vgg is negative of battery, so -6V ,, or actually, GND=Vcc and Vgg=GND ... ant there is also proper FG as Frame Ground ... so things made with different patience than today )) cheers
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7alken

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Aug 4, 2025, 6:04:29 PMAug 4
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of course, almost any picture on the net showing 11pin connector pins GND and Vgg (often as Vcc) means that GND is actually +6V and Vcc is just ZERO ))
(probably some japanese thing 

Mark T

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Aug 4, 2025, 8:43:02 PMAug 4
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Those 1.27mm pitch pin headers are also good for making a plug to insert into turned pin sockets. You just remove alternate pins. The 0.4mm square pins are closer to the size of IC pins than the 0.5mm round pins that are normally used and don’t stress the round pin sockets. If you are fitting them on 2.54mm pitch proto board then use 1.27mm pitch proto board to keep the two rows of header pins at the correct alignment.

7alken

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Aug 5, 2025, 1:49:38 AMAug 5
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hi Mark, ya, I did exactly this with 11pin connector, used 1.27 with pulled pins ... but then came THE question )))...
cant imagine how CE-123P and CE-126P differs, will peek into service manuals ... tried to contact also Birt there, 
my dad was entire life repairing anything with tapes and audio ... memories

https://www.youtube.com/watch?v=sl9GAocr29M
Petr

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