1 REM 2708 Eprom reader program for PPI ISA card
10 lineSize = 16
20 romSize = 1024
30 baseAddr = &H300: configByte = 144: REM Mode 0, A=input, B+C=output
35 noCS = 128: CS = 0
40 aPort = baseAddr: Bport = baseAddr + 1: Cport = baseAddr + 2: ControlPort = baseAddr + 3
50 OUT ControlPort, configByte
60 chksum = 0
65 LET fileName$ = "e2708_1.hex"
70 OPEN fileName$ FOR OUTPUT AS #1
80 PRINT "Dump to " + fileName$
100 FOR lineCount = 0 TO (romSize - lineSize) STEP lineSize
105 addrStr$ = "000" + HEX$(lineCount)
106 PRINT #1, ":10" + RIGHT$(addrStr$, 4) + "00";
107 chksum = chksum - 16: chksum = chksum - lineCount
108 PRINT RIGHT$(addrStr$, 4)
110 FOR addrCount = 0 TO (lineSize - 1)
120 address = lineCount + addrCount
130 hiByte = INT(address / &H100): loByte = address - hiByte * &H100
135 REM PRINT RIGHT$("0" + HEX$(hiByte), 2); RIGHT$("0" + HEX$(loByte), 2); "=";
136 OUT Bport, loByte: OUT Cport, (hiByte + noCS)
137 OUT Cport, (hiByte + CS): dat = INP(aPort): OUT Cport, (hiByte + noCS)
138 PRINT #1, RIGHT$("0" + HEX$(dat), 2); : chksum = chksum - dat
140 NEXT addrCount
150 PRINT #1, RIGHT$("0" + HEX$(chksum), 2)
155 chksum = 0
160 NEXT lineCount
170 PRINT #1, ":00000001FF"
9000 REM base = &h300 = port A
9010 REM base+1 = port B
9020 REM base+2 = port C
9030 REM base+3 = control
9040 REM writing 128 to control puts all port in output mode
9050 REM writing 144 to control puts port A in input mode
9100 REM Port A = data bits
9110 REM Port B = address bits A0-A7
9120 REM Port C low = address bits A8 - 10
9130 REM Port C high, bit 7 = CS*
9140 REM Read cycle: out C:xx000001
9150 REM             out B:xxxxxxxx
9160 REM             out C:xx000000
9170 REM             in  A
9180 REM             out C:xx000001