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Commodore Snipetts

Regarding the 50 Pin Expansion connector

Origin: The origin of the connector would be the same place that the whole design came from as Jim surmised.  The design of the case was the origin of the system design, with the chip designed/inserted next and hardware last. (function, look and feel followed by implementation?)  The expansion connector, along with the DINs, would have come from Ira Velinski and his department in Tokyo, Yoichi Nishimura being one of the engineers that took part and under the guidance of Yoichi Okubo the head of engineering. As this office was run directly by Sam Tramiel this would have been a system design that came from, and was condoned, from the top of the organization.   It arrived in West Chester around the time the PCB board did; the PCB board with bad ground, no ferrite beads and 9 chips that I saw a picture of just recently.

Why we liked it: When we saw it,  it made sense, higher density which hinted at more controls for extending the bus and more grounds to lower the impedance of the overall cartridge and connector. It also made sense from reuse of the metal part and I will assume that the cartridge housings could be reused with a minimum of retooling.

The clincher would be for me of why it made sense would be one of the axioms of design which is to try to not let a user plug something in where it doesn’t belong.  Since a C64 cart had no business being plugged into a TED, and any damage to the system or cart that may result, making it so you couldn’t plug in a C64 cart made sense.
After working on the TED housing the C64/128 looked kind of clunky in comparison the first couple of days.

One of those little tidbits I almost inserted but didn’t know if they digress the story too much, y’all may think I ramble too much as it is.  So in reference to both engineers having the same first name:

 “Lol… you don’t often say an adults first name but I learned to use the Osakan accent on Okubo-san’s name  as a way to differentiate as him and Yash Terakura were from Osaka. The Tokyo employees were visibly frightened of Osakan drivers and having ridden with both Yash and Okubo in Las Vegas I would say it was well earned reputation.  Several times I heard the expression that you are not safe on the sidewalks of Osaka (as they will occasionally drive on them) ”

 

Edited by: bilherd on 2012-04-26 09:29
The ports on the TED machines

The ports on the TED machines always seemed a little cramped for me. Apart from the IEC and video ports, all the ports were higher density, (including the joystick ports).
 
(I have a PLUS4, and love the "form factor" of it - but the joystick ports really narked me off. They didn't hold the cords stably, the adapters were rare as rocking-horse poop, and they seemed just a compromise of function over form. (The Cassette port was similarly scrawny, but that was a hangover from PET days, and was overdue for a tidy-up.). I've read elsewhere that you mentioned that there was simply no room for 2 DB9 ports on the board, designed to fit in the non-breadbox case (which was a very svelte piece of industrial design). 
 
The "DMA" aspect of the 1551 always intrigued me. Was that performed by manually manipulating the address and data busses using the I/O ports of the 6523, or something cleverer?
 
Ooroo
Callan
 

Did you mean the 6551?  If so

Did you mean the 6551?  If so it doesnt act as a DMA master where it would write directly to memory while the processor sleeps, so what happens is the 6551 pulls the Interup line when it gets a byte, the 6502/proc then responds and gets the data on the standard address/data bus and then stores it or operates on it.  What is dife=ferent about using the 6551 is it takes care of turning the serial stream into a full byte of data where as software UARTS have to "bit bang" the serial stream by watching  an I/O line (or interupting on each transition or interupting when a bit time is due.) and then store the resuly.  You can imagine how hard it is to do something else while bit banging a serial port.]
 
Bil

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