MSX Bee Card Development Cards?

Rookie (20)

08-06-2016, 15:08

Randam wrote:

Oh and apparently there were Bee Cards used as telephone cards which had exactly the same connectors and number of connectors as the ones on msx. https://en.wikipedia.org/wiki/Bee_Card#/media/File:Mitsubishi_Kirigamine_BeeCard.jpg

Two interesting similarities here.
(1) both cards have a shortened first pin
(2) Both are labeled BCE rather than the standard BC (Does anyone know what the "E" connotes?)

The biggest difference, however, is that this phone card is significantly thinner. [img][/img]

By Randam

Paragon (1431)

08-06-2016, 22:49

Perhaps the E refers to it being an EEPROM?

I just saw this site: http://www.gerhard-hirsch.com/en7.html see thee first image... Perhaps they know more about it?

By NYYRIKKI

Enlighted (6067)

09-06-2016, 17:21

Randam wrote:

Perhaps the E refers to it being an EEPROM?

My thoughts exactly.. Now the address and data lines are easy to track, but what about VPP and such? Are these documented?

By RetroTechie

Paragon (1563)

09-06-2016, 22:42

My money is on these cards being EEPROM cards (64 Kbit?). If you check this Wiki page, one can see that the connector is basically an (EP)ROM IC pinout (in order!), laid out in a single row. And pin 21 is simply /CS12 equivalent? Not sure why there's an 74LS00 in there at all...

There's different EEPROM types: some that behave mostly like an EPROM, but with an electrical chip-erase function. And some types that have a /WE (write enable) pin, and allow individual byte re-programming.

Many EEPROM chips (size 8 KB and up) support an ID-byte readout mode which serves to identify manufacturer & device type. Something like "raise A9 pin to ~12V".

So to confirm theories, I guess you'd have 2 options:

Make some hardware modifications to a BeePack, to enable ID & write functions (and write some software to give that a try).
Take a BeePack connector, and wire it up to an (external) EPROM programmer.