{MemScan.mc, HGM, 3-Apr-85 20:44:50}
Reserve[0F5F, 0FFF]; {section used by the CP Kernel }
SetTask[0]; StartAddress[Go];
RegDef[address, R, 1]; {Word within bank}
RegDef[rhAddr, RH, 1];
RegDef[addres2, R, 2];
RegDef[rhAdr2, RH, 2];
RegDef[found, R, 4];
RegDef[toAddr, R, 5];
RegDef[toAddrHi, RH, 5];
RegDef[errorCount, R, 6];
RegDef[temp, R, 7];
RegDef[lastBank, R, 0A]; {Must be power of 2}
RegDef[reason, U, 20]; {0 => error, 1 => done}
RegDef[toData, U, 40];
RegDef[toCommand, U, 41];
Set[Setup0, 0];
Set[Setup1, 1];
Set[Setup2, 2];
Set[Setup3, 3];
Set[Setup4, 4];
Set[Setup5, 5];
Set[Setup6, 6];
Set[Setup7, 7];
Set[Setup8, 8];
Set[Setup9, 9];
Set[SetupA, 0A];
Set[SetupB, 0B];
Set[SetupC, 0C];
Set[SetupD, 0D];
Set[Fetch0, 0];
Set[Fetch1, 1];
Set[Fetch2, 2];
Set[Fetch3, 3];
Set[Fetch4, 4];
Set[Fetch5, 5];
Set[Info0, 0];
Set[Info1, 1];
Trap: temp ← RRot1 ErrnIBnStkp, ClrIntErr, CANCELBR[$, 0F], c1, at[0];
Xbus ← temp LRot0, XwdDisp, c2;
DISP2[TrapType], c3;
Parity: GOTO[GoToGo], c1, at[0,4,TrapType];
Init: GOTO[GoToGo], c1, at[1,4,TrapType];
Stack: GOTO[GoToGo], c1, at[2,4,TrapType];
IB: GOTO[GoToGo], c1, at[3,4,TrapType];
GoToGo:
Noop, c2;
Noop, GOTO[Go], c3;
Go: rhAddr ← 0, c1;
Noop, c2;
Noop, c3;
{Setup Misc Board to Interrupt on XACK Timeout}
rhAdr2 ← 4, {Misc CIO Chip} c1;
addres2 ← 090, c2;
addres2 ← addres2 LRot8, {9000} c3;
temp ← addres2 + 0, L0 ← Setup0, {Master Control} c1;
Q ← 1, CALL[Setup], {Reset} c2;
Noop, c3, at[Setup0, 10, SetupRet];
temp ← addres2 + 0, L0 ← Setup1, {Master Control} c1;
Q ← 00, CALL[Setup], {Clear Reset} c2;
Noop, c3, at[Setup1, 10, SetupRet];
temp ← addres2 + 0, L0 ← Setup2, {Master Control} c1;
Q ← 080, CALL[Setup], {MIE} c2;
Noop, c3, at[Setup2, 10, SetupRet];
temp ← addres2 + 20, L0 ← Setup3, {Port A Mode} c1;
Q ← 0, CALL[Setup], {Bit Port} c2;
Noop, c3, at[Setup3, 10, SetupRet];
temp ← addres2 + 23, L0 ← Setup5, {Port A Direction} c1;
Q ← 0FF, CALL[Setup], {All Bits Input} c2;
Noop, c3, at[Setup5, 10, SetupRet];
temp ← addres2 + 0E, L0 ← Setup6, {Port B Data} c1;
Q ← 0F, CALL[Setup], {Disable all outputs} c2;
Noop, c3, at[Setup6, 10, SetupRet];
temp ← addres2 + 2B, L0 ← Setup7, {Port B Direction} c1;
Q ← 0F0, CALL[Setup], {Output on low 4 bits} c2;
Noop, c3, at[Setup7, 10, SetupRet];
temp ← addres2 + 1, L0 ← Setup8, {Master Config Control} c1;
Q ← 084, CALL[Setup], {Enable Ports A+B} c2;
Noop, c3, at[Setup8, 10, SetupRet];
temp ← addres2 + 2C, L0 ← Setup9, {Port B Special IO} c1;
Q ← 40, CALL[Setup], {ONEs Catcher for TOXack} c2;
Noop, c3, at[Setup9, 10, SetupRet];
temp ← addres2 + 2D, L0 ← SetupA, {Port B Polarity} c1;
Q ← 40, CALL[Setup], c2;
Noop, c3, at[SetupA, 10, SetupRet];
temp ← addres2 + 2F, L0 ← SetupB, {Port B Mask} c1;
Q ← 40, CALL[Setup], c2;
Noop, c3, at[SetupB, 10, SetupRet];
temp ← addres2 + 09, L0 ← SetupC, {Port B Command} c1;
Q ← 0C0, CALL[Setup], {Set Interrupt Enable} c2;
Noop, c3, at[SetupC, 10, SetupRet];
temp ← addres2 + 28, L0 ← Setup4, {Port B Mode} c1;
Q ← 4, CALL[Setup], {Bit Port, OR Matcher} c2;
Noop, c3, at[Setup4, 10, SetupRet];
ExtCtrl ← 5, {Init Incr, Zero, UnBlank} c1;
ClrIntErr, c2;
GOTO[MainLoop], c3;
{------------------------------------------------------------------------------------}
MainLoop:
rhAddr ← 0, address ← 0, c1;
Noop, c2;
PreReadLoop:
Noop, c3;
ReadLoop:
MAR ← [rhAddr, address + 0], RawRef, c1;
Noop, c2;
found ← MD, c3;
{Wait long enough for an Interrupt to strike.}
Noop, c1; Noop, c2; Noop, c3;
Noop, c1; Noop, c2; Noop, c3;
Noop, c1; Noop, c2; Noop, c3;
Noop, c1; Noop, c2; Noop, c3;
Noop, c1;
MesaIntBr, c2;
BRANCH[$, MesaIntRead], c3;
Noop, c1;
address ← address + 1, CarryBr, c2;
BRANCH[ReadLoop, $], c3;
NextBank:
Noop, c1;
Q ← rhAddr + 1, c2, LOOPHOLE[niblTiming];
rhAddr ← Q LRot0, c3;
[] ← lastBank - Q, NegBr, c1;
Q ← 1, BRANCH[PreReadLoop, $], c2;
reason ← Q, c3;
Done: ExtCtrl ← 3, {Gets Bumped on rising edge} c1;
ExtCtrl ← 7, c2;
GOTO[MainLoop], c3;
{------------------------------------------------------------------------------------}
MesaIntRead:
reason ← 0, c1;
L1 ← Info1, c2;
CALL[Info], c3;
Q ← errorCount, c1, at[Info1, 10, InfoRet];
Q ← Q + 1, c2;
errorCount ← Q, c3;
MesaIntIsProbablyAParityError:
Noop, c1;
Noop, c2;
GOTO[Go], c3;
FixThisWord:
MAR ← [rhAddr, address + 0], RawRef, c1;
MDR ← found, c2;
Noop, c3;
Fixed: Noop, c1;
Noop, c2;
GOTO[Go], c3;
{------------------------------------------------------------------------------------}
Info:
rhAdr2 ← 4, {Misc CIO Chip} c1;
addres2 ← 090, c2;
addres2 ← addres2 LRot8, {9000} c3;
Q ← 05, L0 ← Fetch0, {RdTODatL} c1;
CALL[Fetch], c2;
toData ← temp, c3, at[Fetch0, 10, FetchRet];
Q ← 04, L0 ← Fetch1, {RdTODatH} c1;
CALL[Fetch], c2;
temp ← temp LRot8, c3, at[Fetch1, 10, FetchRet];
Q ← toData, c1;
temp ← temp or Q, c2;
toData ← temp, c3;
Q ← 03, L0 ← Fetch2, {RdTOCmd} c1;
CALL[Fetch], c2;
toCommand ← temp, c3, at[Fetch2, 10, FetchRet];
Q ← 00, L0 ← Fetch3, {RdTOAdrH} c1;
CALL[Fetch], c2;
toAddrHi ← temp LRot0, c3, at[Fetch3, 10, FetchRet];
Q ← 02, L0 ← Fetch4, {RdTOAdrL} c1;
CALL[Fetch], c2;
toAddr ← temp, c3, at[Fetch4, 10, FetchRet];
Q ← 01, L0 ← Fetch5, {RdTOAdrM} c1;
CALL[Fetch], c2;
temp ← temp LRot8, c3, at[Fetch5, 10, FetchRet];
Q ← toAddr, c1;
Q ← Q or temp, L1Disp, c2;
toAddr ← Q, DISP4[InfoRet], c3;
{------------------------------------------------------------------------------------}
Setup:
Noop, c3;
IO ← [rhAdr2, temp + 0], L0Disp, c1;
MDR ← Q, DISP4[SetupRet], c2;
{------------------------------------------------------------------------------------}
Fetch:
Noop, c3;
IO ← [rhAdr2, addres2 + 0E], {Port B Data} c1;
MDR ← Q + 8, c2;
Noop, c3;
IO ← [rhAdr2, addres2 + 0D], {Port A Data} c1;
Noop, c2;
temp ← MD, c3;
L0Disp, c1;
DISP4[FetchRet], c2;
{------------------------------------------------------------------------------------}