Obie pamięci są 1M X 16-bit DRAM.
Nie jestem pewien zasugerowałem się opisem z montażu pamięci SIMM w ST:
Unfortunately you cannot just make the connections to the various points on the ST's existing DRAM banks as the existing dram will interfere with the signals. There are a number of ways to deal with this;
a. Remove ALL of the dram chips from the ST's motherboard.
b. Disable power and RAS/CAS signals to the dram chips, leaving them in place
Performing (a) is probably the best course of action. Salvaging the existing chips will be difficult however, as potentially expensive and damaging methods are required to get those chips off of the board in one piece. The method here was to use a hobby drill with a cutting disc fitted and to cut the legs off of every chip, finally removing the remaining 'stumps' from the motherboard.
Performing (b) has the advantage that your dram chips are preserved should you ever wish to downgrade and it's less stressful. Disabling power to the chips can be achieved by lifting the inductor L51 just next to the main power connector to the motherboard. This procedure is not however guaranteed as many revisions of the ST motherboard existed. On my test motherboard the power area where L51 forms a circuit also powers the floppy disk drive. Power for the FDD can of course be taken from elsewhere on the board as there may be additional solder points, there are some here directly infront of the main power supply connector. It is only the +5v line which is affected for the FDD, which is the red wire. The existing dram signals that you must disable are RAS0, CAS0L, CAS1L; That's the main bank in 520STFM models. On 1040STFM models or 520ST's with 1Mbyte upgrades, RAS1, CAS1L and CAS1H must also be disabled. This is achieved by lifting the 66ohm resistors R59, R60 and R61 for bank0, and R71, R72, R73 for bank1. If you do not do this then you will be looking at a blank screen when you power-up. It is also debatable as to whether the +5v actually needs to be disabled to the RAM banks, but since the ST's PSU is generally quite small, it makes good practice either way.
