Texas Instruments made two versions of their TMS2564 (which is an 8K EPROM). The more common version is a 28-pin package that is still difficult to find. The most difficult version is the 24-pin package. It was used in the TI DSDD FDC. It appears that all of the 4K EPROMs (i..e., TMS2532, 2732, etc.) have address lines numbered A0->A11. The 8K chips (2764) have address lines A0 ->A12. I am looking for the datasheet for the TMS2564 24-PIN package. I have been unable to find it on ;line. Can anyone help me out? I know it muxt exist somewhere in cyberspace!