; ; 3_0.eqn - disable motherboard DRAM ; ; This doesn't actually need to use its P3-P0 inputs. ; But if we don't include them, the GAL pulls them high a little. ; Enough to sometimes interfere with other users of P3-P0. ; TITLE MTX with 3x8KB ROM and 0KB RAM PATTERN A REVISION 1.1 AUTHOR ANDY KEY COMPANY NYANGAU.ORG DATE 10/8/14 CHIP 3_0 GAL16V8 A13 A14 A15 P2 R1 R2 P1 MREQL RDL GND I2H4L P0 RELCPMH RAM NA15 CE64 CEA P3 R0 VCC EQUATIONS /CEA = /RELCPMH * /A15 * /A14 * /A13 * /MREQL * /RDL /CE64 = /RELCPMH * /R2 * /R1 * /A15 * /A14 * A13 * /MREQL * /RDL + /RELCPMH * R2 * R1 * R0 * /A15 * /A14 * A13 * /MREQL * /RDL /NA15 = /A15 /RAM = RELCPMH * /RELCPMH * P3 * /P3 * P2 * /P2 * P1 * /P1 * P0 * /P0