 
ô > RAMTest/s Bô Based on www.willegal.net/appleii/6502mem.htm translation of :ô Carl Moser's 6502 RAM test in Issue 1 Compute, 1979. (: 2-ô Destructively tests almost all 6502 RAM <#ô Run on I/O, tests &0E00-&7FFF F$ô Run on Tube, tests &0500-&F7FF P$ô On error, prints pp aaaa bb tt Z;ô pp=pass, aaaa=address, bb=byte from ram, tt=test byte d: nCô On completion, language memory zeroed and language re-entered x: ‚7OSRDCH=&FFE0:OSNEWL=&FFE7:OSWRCH=&FFEE:OSBYTE=&FFF4 ŒÞ mcode% &180 –:  start=&80:end=&82:addr=&84 ªtest=&86:pass=&87 ´: ¾ã P=0 ¸ 1 ÈP%=&400:O%=mcode% Ò[OPT P*3+4 Ü
.exec% æ6JMP go%:BRK:BRK:BRK            \ Header identifies ð6EQUB &42:EQUB copy-exec%       \ this as 6502 code úEQUB &10:EQUS "RAMTEST"&EQUB &00:EQUS "1.00 (15 Feb 2010)"	.copy&EQUB 0:EQUS"(C)J.G.Harston":EQUB 0":,.go%6ELDA #&82:JSR OSBYTE            \ What side of the Tube are we on?@7LDA #&0E:LDX #&80              \ start, end for I/OJINY:BEQ setlimitsT8LDA #&05:LDX #&F8              \ start, end for Tube^.setlimitsh;STA start+1:STX end+1          \ Set memory test limitsr:LDA #0:TAY                     \ Initial test byte=&00|\STA start+0:\STA end+0†
.loop0STA testš:¤\ Test type in Y®\ 0 = all zeros¸\ 1 = all onesÂ"\ 2 = move 1s up through bytesÌ"\ 3 = move 0s up through bytesÖ\ 4 = low byte of addressà\ 5 = high byte of addressê\ 6 = all zeros againô:þ3\ Test all memory with test byte specified by Y3\ ---------------------------------------------
.loop1\LDA start+0:\STA addr+0&ELDX #0:STX addr+0              \ Point to start of memory to test0LDA start+1:STA addr+1::D.\ On pass 4 and 5 use address as test byteN.\ ----------------------------------------X
.loop2bBLDA addr+0:CPY #4:BCC testbyte \ pass<4, use current test bytelDBEQ setbyte                    \ pass=4, use low byte of addressvELDA addr+1:CPY #6:BCS testbyte \ pass=5, use high byte of address€.setbyteŠSTA test”:ž!\ Test memory with test value¨!\ ---------------------------².testbyte¼2LDA test                       \ Get test byteÆLSTA (addr,X):LDA (addr,X)      \ Store test byte and fetch it back againÐLCMP test:BEQ no_error          \ Fetched value didn't match stored valueÚ:ä\ Error occured, report itî\ ------------------------ø3PHA                            \ Save test byte7TYA:JSR PrHex                  \ Output pass numberLDA addr+1:JSR PrHexSpc3LDA addr+0:JSR PrHex           \ Output address 7PLA:JSR PrHexSpc               \ Output actual byte*5LDA test:JSR PrHexSpc          \ Output test byte4JSR OSNEWL>:H.no_errorR9INC addr+0:BNE P%+4:INC addr+1 \ Step to next address\%\LDA addr+0:\CMP end+0:\BNE loop2f8LDA addr+1:CMP end+1:BNE loop2 \ Loop to test memoryp:z.\ All memory tested, prepare for next pass„.\ ----------------------------------------ŽCPY #1:BCC next0:BEQ next1˜CPY #3:BCC next2:BEQ next3¢CPY #5:BEQ next5:BCS done¬I:                               \ Drop through to INC Y and loop back¶
.next0ÀBDEC test:INY:BNE loop1          \ test byte=&FF, retest memoryÊ
.next1ÔBSTY test:INY:BNE loop1          \ test byte=&01, retest memoryÞ
.next2èDROL test:BCC loop1              \ Move set bit up, retest memoryòQLDA #&FE:STA test:INY:BNE loop1 \ Set bits done, test byte=&FE, retest memoryü
.next3FROL test:BCS loop1              \ Move clear bit up, retest memory
.next5GLDA #0:INY:BNE loop0            \ Clear bits done, do address bytes$:.	.done8LDA #—"O":JSR OSWRCHBLDA #—"K":JSR OSWRCHL9JSR OSRDCH:JSR OSNEWL           \ Wait for a keypressV9LDA #252:LDY #255               \ X will still be &00`?JSR OSBYTE:LDA #142:JMP OSBYTE  \ Re-enter current languagej:t.PrHexSpc~9PHA:LDA #—" ":JSR OSWRCH:PLA  \ Print a leading spaceˆ
.PrHex’PHA:LSR A:LSR A:LSR A:LSR AœJSR PrNyb:PLA¦
.PrNyb°!€ #15:CMP #10:BCC P%+4:ADC #6ºADC #—"0":JMP OSWRCHÄ]:íÎ;ñ"*SAVE RAMTEST ";~mcode%;" ";~O%;" ";~exec%;" ";~exec%ÿ