• Please review our updated Terms and Rules here

Incompatability of AST Sixpackplus and NEC V20 Experienced with Clone XT

512K OK
08 RAM Bad 80004
So, bit 3 in the bank starting at 512K.

How are the banks numbered? From the BUS End (inside row out) or end of the card? Is the parity chip the bus plug edge or top edge of the card? Thanks Ed
A quick experiment shows that it is the same as used in the first version of the card:
Banks run from center of card to edge of card.
Bits: From top to bottom are P/7/6/5/4/3/2/1/0
 
Making Progress. Removed C45, checked with Ohm meter and short was gone.
I am sorry if any of the following is 'suck eggs'.

For a replacement capacitor, you have the option of using an aluminium electrolytic type. In fact, that is what AST used on my card. Photo at [here].
Height must not be such that the capacitor can make contact with an adjacent card.

Positive leg of capacitor into positive hole. For C45, the positive hole is the one closest to the DB25 connector.

In this application, a larger capacitance value is okay, e.g. 33uF

You can also use a higher voltage rating, e.g. 25V
 
SUCCESS!! Rotated memory bank 4 & 5 and that got RAM OK up to 576. Then played swap and test until found two bad chips. Everything is now working except serial port given removal of C45. Really do not need it now and will leave it for a future activity as I will have to buy solder sucker, iron and capacitor(s).

Actually, the card does not have all chips populated, so I expect the serial chip(s) are what is missing.

Thank you so much again for all your guidance and coaching. I would not have been able to get it running without your and the forum support.

Buying from e-bay is a risk; sometimes you win and other times you are challenged to find value in what you buy.

We can now consider this thread closed and successful. Have a good weekend.
Best regards
Ed
 
I placed tape over the B7 contact and installed installed card. Computer started OK!! Of course did not recognize card had been installed.
 
Back
Top