- A GAL which can be used to get the missing 0.5MB back when adding one bank of 1MBit-DRAMs to a 1MB-ST. This makes the old two 512K banks look like 1 2MB bank to the MMU (from which only the first half is working). This must be the second RAM bank: Source file and Jedec file.
- Equations for a different version of such a GAL, from an old news posting by Ernst Schwab.
- A patch for broken Zyxel U1496E custom chips. After a lightning strike, often the off-hook/dialing outputs of the ZX1002 chip are broken, along with the relay driver. This GAL re-creates these two signals and thus makes it possible to repair the modem without replacing the custom chip:
- A HD module which supplies the correct clock needed to use high-density floppy drives in a ST/STE (Photo). The module supports two floppy drives, does automatic step-rate adaption, and makes sure that the FDC gets the normal 8MHz clock when no floppy is accessed. It will also double the step signal for drive B (for 40-track 5.25″ floppy disks), and correct the step rate to 6ms in that case:
bottom artwork (300dpi)
GAL source (normal version)
GAL jedec (normal version)
GAL source (inverted HD inputs)
GAL jedec (inverted HD inputs)