I recently bought a memory board Legend Industries 128KDE Soft Disk
I found some documentation on the web (a manual in pdf)
the board described in the pdf has a flag cable linking the board to the motherboard
(as a standard language card)
the one I received is without this flat cable
the socket for the 4116 is missing and in place there are (apparently 2 capacitors)
the socket with the flat cable contains a 74ls04
I checked the tracks it is clear that this board was not designed to contains a 4116
are you aware of the 2 versions of this board ?
any schematics somewhere ?
any manual ?
I compare the photo of both board, the electonics looks almost the same ?
any idea of the use of the flat cable connected on a 4116 ?
I thought it was for ras/cas but apparently they are regenerated by the board
any idea ?
thanks
Greetings,
You are probably talking of this card, right ?
The A2DP shows pictures of the "linked" version, which seems to be different on the solder side, in the top left and bottom right corners.
Note that the back picture doesn't match the front one : no soldered component and vias present that don't appear on the front picture.
As noted in the manual, the flat cable is indeed used to get timing signals from the 4116 socket on the motherboard, like most of the RAM cards did.
But some don't : they generate their own timings like this one and that one (note the potentiometer to adjust timings).
Is the card working (i.e. recognized as a standard 16 Ko RAM Card) ?
yes, it's this board, initially it was crashing the bus when connected
I had to remove a lot of oxydes ont the chip pins
and change 2 chips dead gates / and pins too damaged on another one...
now the card ils loaded with integer basic when I boot on a dos 3.3 master
I have to find some memory test to be sure it's fully working
thanks