The RX01\/RX02 Pocket Service Guide DY Bootstrap<\/h4>\n
The PSG DY Bootstrap appears at Table 1-10 of the RX01\/RX02 Pocket Service Guide (DEC Order Number EK-RX012-PS-002). A thumbnail image of that table is shown here on the right. Click on it for a full-size version.<\/p>\n The PSG DY Bootstrap has the following main features:<\/p>\n I have re-created the source code for the PSG DY Bootstrap.<\/p>\n Here it is:<\/p>\n You can also download the source code and assembly listing files for the PSG DY Bootstrap here if you need them:<\/p>\n dy-psg-bootstrap.mac<\/a><\/p>\n dy-psg-bootstrap.lst<\/a><\/p>\n<\/div>\n I’ve modified the PSG DY Bootstrap so that:<\/p>\n To modify the PSG DY Bootstrap so that it boots from Unit 1:<\/p>\n To modify the PSG DY Bootstrap so that it works with single-density disks:<\/p>\n The listing below includes self-modifying code (at lines 92 to 100) so that it can attempt to boot a single-density disk, if the initial attempt to boot a dual-density disk fails.<\/p>\n Here is the listing:<\/p>\n You can also download the source code and assembly listing files for my Dual-Density DY Bootstrap here if you need them:<\/p>\n dy-dual-density-bootstrap.mac<\/a><\/p>\n dy-dual-density-bootstrap.lst<\/a><\/p>\n<\/div>\n The PDP-11 Microcomputer Interfaces Handbook 1983-84 (DEC Order Number EB-23144-18) includes at Pages 484-485 separate ODT Bootstraps for double-density and single-density RX02 disks.<\/p>\n A copy of Pages 484-485 is available here<\/a>.<\/p>\n Whoever typed up the Handbook DDEN RX02 Bootstrap must have been having a very bad day. It contains the following 6 errors and deficiencies:<\/p>\n The first 3 errors in the list above result in a BMI (“branch if minus”) instruction to an address that is outside the range of the bootstrap (they would each branch to address 001146). The second and third errors also happen to be entirely wrong instructions: both are erroneous BMI instructions (to address 1146) when in fact 1046 should be a “MOVB R4,(R3)” instruction and 1062 should be a “BIT R0,(R1)” instruction.<\/p>\n The fourth error is a simple typo (a “0” was left out after the first digit).<\/p>\n The fifth error is perhaps more a deficiency than an error. The bootstrap only transfers a total of 512 bytes (being Sectors 1 and 3, each of 256 bytes) to RAM. Presumably this was adequate for early versions of RT-11. However, it is not sufficient for RT-11 V5.3, which requires 1024 bytes to be transferred. If you only transfer 512 bytes, RT-11 V5.3 will not boot up on the first attempt after power cycling the PDP-11. Strangely, if you then re-enter and re-run the bootstrap a second or subsequent time, RT-11 V5.3 will run. For this reason, I don’t recommend using this bootstrap for RT-11 V5.3 unless you relocate it to address O’002000, and modify the word at 1124 so that all 1024 bytes get loaded. The code below is relocatable, so moving it to O’002000 doesn’t change any of the values to be entered via ODT, other than the start address.<\/p>\n The sixth error is simply a redundant word. The word at 1136 (120427) is never executed and is not referenced by any instruction.<\/p>\n Here is the Handbook DDEN RX02 Bootstrap with all 6 errors\/deficiencies corrected. Note that it is now relocated to O’002000.<\/p>\n You can also download the source code and assembly listing files for the Handbook DDEN RX02 Bootstrap here if you need them:<\/p>\n dy-dbl-den-bootstrap.mac<\/a><\/p>\n dy-dbl-den-bootstrap.lst<\/a><\/p>\n<\/div>\n As mentioned earlier, the PDP-11 Microcomputer Interfaces Handbook 1983-84 (DEC Order Number EB-23144-18) also includes at Pages 484-485 an ODT Bootstrap for single-density RX02 disks.<\/p>\n The good news is that this bootstrap has less issues than its double-density counterpart. However, there are still a couple of changes that should be made, if you want to use this bootstrap to load RT-11 V5.3:<\/p>\n The first change suggested above relates to the total number of bytes transferred by the bootstrap. The bootstrap only transfers a total of 512 bytes (being Sectors 1, 3, 5 & 7, each of 128 bytes) to RAM. As mentioned earlier, this is not sufficient for RT-11 V5.3, which requires 1024 bytes to be transferred (see comments earlier about the behaviour of RT-11 V5.3 if only 512 bytes are transferred). For this reason, I recommend relocating this bootstrap to address O’002000, and modifying the word at 1124 so that 1024 bytes (being the 8 odd-numbered sectors from D’01 to D’15) get loaded. The code below is relocatable, so moving it to O’002000 doesn’t change any of the values to be entered via ODT, other than the start address.<\/p>\n The second change is simply removing a redundant word. The word at 1136 (000003) is never executed and is not referenced by any instruction.<\/p>\n Here is the Handbook SDEN RX02 Bootstrap with both changes made. Note that it is now relocated to O’002000.<\/p>\n You can also download the source code and assembly listing files for the Handbook SDEN RX02 Bootstrap here if you need them:<\/p>\n dy-sgl-den-bootstrap.mac<\/a><\/p>\n dy-sgl-den-bootstrap.lst<\/a><\/p>\n<\/div>\n I’ve examined the sector data on Track 1 of a single-density RX02 RT-11 V5.3 disk. I did this using ImageDisk. On the single-density disk, it is clear that there is non-zero data in Sectors 1, 3, 5, 7, 9, 15 and 17 (in Sector 13 the data was all zeroes).<\/p>\n The boot menu that is on the M8189 (KDF11-BA) is capable of booting both single-density and double-density RX02 disks. I assume it tries one density first, and if that fails, it then tries the other density. However, I’ve not examined the code on the M8189 to confirm this.<\/p>\n There are other RX02 bootstraps that I have not examined. For example, there is a DY bootstrap on the M9312<\/a>.<\/p>\n All the above bootstraps were tested with the following hardware\/software:<\/p>\n I found these documents useful when producing the source code files shown on this page:<\/p>\n RX02 Floppy Disk System User’s Guide<\/a> (Dec Order Number EK-RX02-UG-001): Comprehensive information about programming the RX02 controllers.<\/p>\n DEC’s RX01\/RX02 Pocket Service Guide<\/a> (DEC Order Number EK-RX012-PS-002). This document includes bootstrap loaders for the RX8\/RX28, RX11\/RXV11 and RX211\/RXV211. It also includes a summary of the registers used on the RX01\/RX02 controllers.<\/p>\n Alan Rosenthal’s PDP-11 instruction reference<\/a>: Useful detailed description of the PDP-11 instruction set.<\/p>\n PDP-11 Macro-11 Language Reference Manual (DEC Order Number AA-5075A-TC)<\/a><\/p>\n![\"\"](\"https:\/\/i0.wp.com\/avitech.com.au\/wp-content\/uploads\/2017\/06\/dy-loader-from-pocket-service-guide.jpg?ssl=1\")
<\/a><\/p>\n\n
\r\n 1 .TITLE PSG BOOTSTRAP FOR RX211\/RXV21\r\n 2\r\n 3 ; THIS IS THE RX211\/RXV21 BOOTSTRAP THAT APPEARS IN\r\n 4 ; THE RX01\/RX02 POCKET SERVICE GUIDE (DEC ORDER NUMBER\r\n 5 ; EK-RX012-PS-002). IT BOOTS ONLY DOUBLE-DENSITY\r\n 6 ; DISKS.\r\n 7 ;\r\n 8 ; MALCOLM MACLEOD - 11 JUNE 2017\r\n 9\r\n10 000000 .ASECT\r\n11 002000 .=002000\r\n12\r\n13 177170 RX2CS = 177170 ; RXV21 CONTROL\/STATUS REGISTER\r\n14 177172 RX2DB = 177172 ; RXV21 DATA BUFFER REGISTER\r\n15 000200 WRDCNT = ^D128 ; 128 FOR DBL-DEN, 64 FOR SGL-DEN\r\n16 100240 MASK = 100240 ; BIT 15=ERR, 7=XFER-RQST, 5=DONE\r\n17\r\n18 002000 012701 177170 MOV #RX2CS,R1 ; PUT ADDR OF RX2CS INTO R1\r\n19 002004 012700 100240 MOV #MASK,R0 ; PUT BIT MASK INTO R0\r\n20 002010 005002 CLR R2 ; CLEAR BUS ADDR (DMA DEST'N ADDR)\r\n21 002012 012705 000200 MOV #WRDCNT,R5 ; PUT WORD COUNT (128) INTO R5\r\n22 002016 012704 000401 MOV #401,R4 ; TRACK 1, SECTOR 1\r\n23 002022 012703 177172 $1: MOV #RX2DB,R3 ; PUT ADDR OF RX2DB IN R3\r\n24\r\n25 ; CHECK THAT THE RXV21 IS READY\r\n26\r\n27 002026 030011 $2: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n28 002030 001776 BEQ $2 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n29 002032 100440 BMI QUIT ; HALT IF ERR IS SET\r\n30\r\n31 ; INITIATE A READ-SECTOR COMMAND\r\n32\r\n33 002034 012711 000407 MOV #407,(R1) ; DEN=DDEN, UNIT=0, FN=RD-SECTOR, GO\r\n34 002040 030011 $3: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n35 002042 001776 BEQ $3 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n36 002044 100433 BMI QUIT ; HALT IF ERR IS SET\r\n37 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n38 002046 110413 MOVB R4,(R3) ; WRITE SECTOR NUMBER TO RX2DB\r\n39 002050 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 0-7\r\n40 002052 030011 $4: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n41 002054 001776 BEQ $4 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n42 ; CODE ASSUMES THAT XFER-RQST (NOT ERR OR DONE) IS NOW SET\r\n43 002056 110413 MOVB R4,(R3) ; WRITE TRACK NUMBER TO RX2DB\r\n44\r\n45 ; RXV21 IS NOW READING SECTOR DATA INTO ITS OWN BUFFER\r\n46\r\n47 002060 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 15-8\r\n48 002062 030011 $5: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n49 002064 001776 BEQ $5 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n50 002066 100422 BMI QUIT ; HALT IF ERR IS SET\r\n51\r\n52 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n53\r\n54 ; THE SECTOR DATA IS NOW IN RXV21'S DATA BUFFER.\r\n55 ; PREPARE TO TRANSFER SECTOR DATA FROM RXV21 TO RAM BY DMA\r\n56\r\n57 002070 012711 000403 MOV #403,(R1) ; DEN=DDEN, UNIT=ANY, FN=EMPTY-BUF, GO\r\n58 002074 030011 $6: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n59 002076 001776 BEQ $6 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n60 002100 100415 BMI QUIT ; HALT IF ERR IS SET\r\n61 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n62 002102 010513 MOV R5,(R3) ; LD WORD COUNT INTO RX2WC VIA RX2DB\r\n63 002104 030011 $7: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n64 002106 001776 BEQ $7 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n65 002110 100411 BMI QUIT ; HALT IF ERR IS SET\r\n66 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n67 002112 010213 MOV R2,(R3) ; LD BUS ADDRS INTO RX2BA VIA RX2DB\r\n68\r\n69 ; DATA (256 BYTES) IS NOW BEING COPIED TO RAM VIA DMA\r\n70\r\n71 002114 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n72 002116 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n73 002120 122424 CMPB (R4)+,(R4)+ ; INCREMENT SECTOR NUMBER BY 2\r\n74 002122 120427 000007 CMPB R4,#7 ; SECTORS 1, 3, 5 & 7 WILL BE READ\r\n75 002126 003737 BLE $2 ; LOOP BACK AND DO NEXT SECTOR\r\n76 002130 005000 CLR R0 ; BOOT DOESN'T WORK WITHOUT THIS\r\n77 002132 005007 CLR PC ; GO TO ADDR ZERO\r\n78 002134 000000 QUIT: HALT\r\n79\r\n80 000001 .END\r\n<\/pre>\n
Dual-Density RX02 Bootstrap<\/h4>\n
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\r\n 1 .TITLE DUAL-DENSITY BOOTSTRAP FOR RX02\r\n 2\r\n 3 ; THIS BOOTSTRAP IS DERIVED FROM THE RX211\/RXV21\r\n 4 ; BOOTSTRAP THAT APPEARS IN THE RX01\/RX02 POCKET SERVICE\r\n 5 ; GUIDE (DEC ORDER NUMBER EK-RX012-PS-002).\r\n 6 ;\r\n 7 ; IT HAS BEEN MODIFIED SO THAT:\r\n 8 ; * IT CAN BE USED FOR UNIT 0 OR UNIT 1\r\n 9 ; * IT WILL FIRST ATTEMPT TO BOOT A DOUBLE-DENSITY DISK.\r\n 10 ; IF THAT FAILS, IT WILL THEN ATTEMPT TO BOOT A\r\n 11 ; SINGLE-DENSITY DISK.\r\n 12 ;\r\n 13 ; THE CODE SHOWN BELOW IS FOR UNIT 0. TO BOOT FROM UNIT 1:\r\n 14 ; * CHANGE THE WORD AT 002036 FROM 000407 TO 000427\r\n 15 ; * CHANGE THE WORD AT 002132 FROM 000000 TO 000001\r\n 16 ;\r\n 17 ; MALCOLM MACLEOD - 11 JUNE 2017\r\n 18\r\n 19 000000 .ASECT\r\n 20 002000 .=002000\r\n 21\r\n 22 177170 RX2CS = 177170 ; RXV21 CONTROL\/STATUS REGISTER\r\n 23 177172 RX2DB = 177172 ; RXV21 DATA BUFFER REGISTER\r\n 24 000200 WRDCNT = ^D128 ; 128 FOR DBL-DEN, 64 FOR SGL-DEN\r\n 25 100240 MASK = 100240 ; BIT 15=ERR, 7=XFER-RQST, 5=DONE\r\n 26\r\n 27 002000 012701 177170 START: MOV #RX2CS,R1 ; PUT ADDR OF RX2CS INTO R1\r\n 28 002004 012700 100240 MOV #MASK,R0 ; PUT BIT MASK INTO R0\r\n 29 002010 005002 CLR R2 ; CLEAR BUS ADDR (DMA DEST'N ADDR)\r\n 30 002012 012705 000200 MOV #WRDCNT,R5 ; PUT WORD COUNT (128) INTO R5\r\n 31 002016 012704 000401 MOV #401,R4 ; TRACK 1, SECTOR 1\r\n 32 002022 012703 177172 $1: MOV #RX2DB,R3 ; PUT ADDR OF RX2DB IN R3\r\n 33\r\n 34 ; CHECK THAT THE RXV21 IS READY\r\n 35\r\n 36 002026 030011 $2: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 37 002030 001776 BEQ $2 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 38 002032 100441 BMI QUIT ; HALT IF ERR IS SET\r\n 39\r\n 40 ; INITIATE A READ-SECTOR COMMAND\r\n 41\r\n 42 002034 012711 000407 MOV #407,(R1) ; DEN=DDEN, UNIT=0, FN=RD-SECTOR, GO\r\n 43 002040 030011 $3: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 44 002042 001776 BEQ $3 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 45 002044 100434 BMI QUIT ; HALT IF ERR IS SET\r\n 46 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 47 002046 110413 MOVB R4,(R3) ; WRITE SECTOR NUMBER TO RX2DB\r\n 48 002050 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 0-7\r\n 49 002052 030011 $4: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 50 002054 001776 BEQ $4 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 51 ; CODE ASSUMES THAT XFER-RQST (NOT ERR OR DONE) IS NOW SET\r\n 52 002056 110413 MOVB R4,(R3) ; WRITE TRACK NUMBER TO RX2DB\r\n 53\r\n 54 ; RXV21 IS NOW READING SECTOR DATA INTO ITS OWN BUFFER\r\n 55\r\n 56 002060 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 15-8\r\n 57 002062 030011 $5: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 58 002064 001776 BEQ $5 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 59 002066 100423 BMI QUIT ; HALT IF ERR IS SET\r\n 60\r\n 61 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 62\r\n 63 ; THE SECTOR DATA IS NOW IN RXV21'S DATA BUFFER.\r\n 64 ; PREPARE TO TRANSFER SECTOR DATA FROM RXV21 TO RAM BY DMA\r\n 65\r\n 66 002070 012711 000403 MOV #403,(R1) ; DEN=DDEN, UNIT=ANY, FN=EMPTY-BUF, GO\r\n 67 002074 030011 $6: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 68 002076 001776 BEQ $6 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 69 002100 100416 BMI QUIT ; HALT IF ERR IS SET\r\n 70 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 71 002102 010513 MOV R5,(R3) ; LD WORD COUNT INTO RX2WC VIA RX2DB\r\n 72 002104 030011 $7: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 73 002106 001776 BEQ $7 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 74 002110 100412 BMI QUIT ; HALT IF ERR IS SET\r\n 75 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 76 002112 010213 MOV R2,(R3) ; LD BUS ADDRS INTO RX2BA VIA RX2DB\r\n 77\r\n 78 ; DATA (256 BYTES) IS NOW BEING COPIED TO RAM VIA DMA\r\n 79\r\n 80 002114 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n 81 002116 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n 82 002120 122424 CMPB (R4)+,(R4)+ ; INCREMENT SECTOR NUMBER BY 2\r\n 83 002122 120427 000007 CMPB R4,#7 ; SECTORS 1, 3, 5 & 7 WILL BE READ\r\n 84 002126 003737 BLE $2 ; LOOP BACK AND DO NEXT SECTOR\r\n 85 002130 012700 000000 MOV #0,R0 ; BOOT DEVICE IS UNIT 0\r\n 86 002134 005007 CLR PC ; GO TO ADDR ZERO\r\n 87\r\n 88 ; ERRORS ALWAYS BRANCH TO HERE. ON FIRST ERROR (DURING\r\n 89 ; DDEN ATTEMPT) WE CHANGE TO SDEN MODE AND TRY AGAIN. ON\r\n 90 ; SECOND ERROR, WE HALT.\r\n 91\r\n 92 002136 000005 QUIT: RESET ; RESET ALL I\/O DEVICES\r\n 93 002140 012700 002000 MOV #START,R0 ; LOAD R0 WITH START ADDRESS\r\n 94 002144 012701 000400 MOV #400,R1 ; SETUP MASK BYTE\r\n 95 002150 006260 000014 ASR 14(R0) ; CHANGE WRDCNT TO 64 DECIMAL\r\n 96 002154 040160 000036 BIC R1,36(R0) ; CHANGE READ-SECTOR CMD TO SDEN\r\n 97 002160 040160 000072 BIC R1,72(R0) ; CHANGE EMPTY-BUFFER CMD TO SDEN\r\n 98 002164 012760 000017 000124 MOV #17,124(R0) ; CHANGE LAST SECTOR TO D'15\r\n 99 002172 005060 000136 CLR 136(R0) ; PUT HALT AT QUIT LOCATION\r\n100 002176 000700 BR START ; GO BACK AND TRY SDEN MODE\r\n101\r\n102 000001 .END\r\n<\/pre>\n
Microcomputer Interfaces Handbook Double-Density RX02 Bootstrap<\/h4>\n
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\r\n 1 .TITLE DBL-DENSITY BOOTSTRAP FOR RXV21\r\n 2\r\n 3 ; THIS IS THE RXV21 DOUBLE-DENSITY BOOTSTRAP THAT APPEARS\r\n 4 ; AT PAGE 484 OF THE PDP-11 MICROCOMPUTER INTERFACES\r\n 5 ; HANDBOOK 1983-84 (DEC ORDER NUMBER EB-23144-18).\r\n 6 ;\r\n 7 ; NOTE: THE DEC BOOTSTRAP HAS SIX ERRORS AND DEFICIENCIES\r\n 8 ; IN IT (AT ADDR 1032, 1046, 1062, 1100, 1124 and 1136).\r\n 9 ; THOSE ERRORS ARE CORRECTED IN THE SOURCE CODE BELOW.\r\n 10 ;\r\n 11 ; NOTE THAT CORRECTING THE DEFICIENCY AT 1124 (SO THAT\r\n 12 ; 1024 BYTES ARE LOADED, RATHER THAN 512) ALSO REQUIRES\r\n 13 ; THIS BOOTLOADER TO BE RELOCATED TO ADDRESS 002000.\r\n 14 ;\r\n 15 ; MALCOLM MACLEOD - 11 JUNE 2017\r\n 16\r\n 17 000000 .ASECT\r\n 18 002000 .=002000\r\n 19\r\n 20 177170 RX2CS = 177170 ; RXV21 CONTROL\/STATUS REGISTER\r\n 21 177172 RX2DB = 177172 ; RXV21 DATA BUFFER REGISTER\r\n 22 000200 WRDCNT = ^D128 ; 128 FOR DBL-DEN, 64 FOR SGL-DEN\r\n 23 100240 MASK = 100240 ; BIT 15=ERR, 7=XFER-RQST, 5=DONE\r\n 24 002132 QUIT = GO-2 ; DEC HACK: BRANCHES TO A HALT\r\n 25\r\n 26 002000 012700 100240 MOV #MASK,R0 ; PUT BIT MASK INTO R0\r\n 27 002004 012701 177170 MOV #RX2CS,R1 ; PUT ADDR OF RX2CS INTO R1\r\n 28 002010 005002 CLR R2 ; CLEAR BUS ADDR (DMA DEST'N ADDR)\r\n 29 002012 012705 000200 MOV #WRDCNT,R5 ; PUT WORD COUNT (128) INTO R5\r\n 30 002016 012704 000401 MOV #401,R4 ; TRACK 1, SECTOR 1\r\n 31 002022 012703 177172 $1: MOV #RX2DB,R3 ; PUT ADDR OF RX2DB IN R3\r\n 32\r\n 33 ; CHECK THAT THE RXV21 IS READY\r\n 34\r\n 35 002026 030011 $2: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 36 002030 001776 BEQ $2 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 37 002032 100437 BMI QUIT ; HALT IF ERR IS SET\r\n 38\r\n 39 ; INITIATE A READ-SECTOR COMMAND\r\n 40\r\n 41 002034 012711 000407 MOV #407,(R1) ; DEN=DDEN, UNIT=0, FN=RD-SECTOR, GO\r\n 42 002040 030011 $3: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 43 002042 001776 BEQ $3 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 44 002044 100432 BMI QUIT ; HALT IF ERR IS SET\r\n 45 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 46 002046 110413 MOVB R4,(R3) ; WRITE SECTOR NUMBER TO RX2DB\r\n 47 002050 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 0-7\r\n 48 002052 030011 $4: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 49 002054 001776 BEQ $4 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 50 ; CODE ASSUMES THAT XFER-RQST (NOT ERR OR DONE) IS NOW SET\r\n 51 002056 110413 MOVB R4,(R3) ; WRITE TRACK NUMBER TO RX2DB\r\n 52\r\n 53 ; RXV21 IS NOW READING SECTOR DATA INTO ITS OWN BUFFER\r\n 54\r\n 55 002060 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 15-8\r\n 56 002062 030011 $5: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 57 002064 001776 BEQ $5 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 58 002066 100421 BMI QUIT ; HALT IF ERR IS SET\r\n 59\r\n 60 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 61\r\n 62 ; THE SECTOR DATA IS NOW IN RXV21'S DATA BUFFER.\r\n 63 ; PREPARE TO TRANSFER SECTOR DATA FROM RXV21 TO RAM BY DMA\r\n 64\r\n 65 002070 012711 000403 MOV #403,(R1) ; DEN=DDEN, UNIT=ANY, FN=EMPTY-BUF, GO\r\n 66 002074 030011 $6: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 67 002076 001776 BEQ $6 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 68 002100 100414 BMI QUIT ; HALT IF ERR IS SET\r\n 69 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 70 002102 010513 MOV R5,(R3) ; LD WORD COUNT INTO RX2WC VIA RX2DB\r\n 71 002104 030011 $7: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 72 002106 001776 BEQ $7 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 73 002110 100410 BMI QUIT ; HALT IF ERR IS SET\r\n 74 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 75 002112 010213 MOV R2,(R3) ; LD BUS ADDRS INTO RX2BA VIA RX2DB\r\n 76\r\n 77 ; DATA (256 BYTES) IS NOW BEING COPIED TO RAM VIA DMA\r\n 78\r\n 79 002114 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n 80 002116 060502 ADD R5,R2 ; ADD 128 DEC TO BUS ADDRESS\r\n 81 002120 122424 CMPB (R4)+,(R4)+ ; INCREMENT SECTOR NUMBER BY 2\r\n 82 002122 120427 000007 CMPB R4,#7 ; SECTORS 1, 3, 5 & 7 WILL BE READ\r\n 83 002126 003735 BLE $1 ; LOOP BACK AND DO SECTOR NUMBER 3\r\n 84 002130 012700 000000 MOV #0,R0 ; PUT UNIT NUMBER OF BOOT DRIVE IN R0\r\n 85 002134 005007 GO: CLR PC ; GO TO ADDR ZERO\r\n 86\r\n 87 000001 .END\r\n<\/pre>\n
Microcomputer Interfaces Handbook Single-Density RX02 Bootstrap<\/h4>\n
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\r\n 1 .TITLE SGL-DENSITY BOOTSTRAP FOR RXV21\r\n 2\r\n 3 ; THIS IS THE RXV21 SINGLE-DENSITY BOOTSTRAP THAT APPEARS\r\n 4 ; AT PAGE 484 OF THE PDP-11 MICROCOMPUTER INTERFACES\r\n 5 ; HANDBOOK 1983-84 (DEC ORDER NUMBER EB-23144-18).\r\n 6 ;\r\n 7 ; NOTE: THE DEC BOOTSTRAP HAS TWO DEFICIENCIES IN IT\r\n 8 ; (AT ADDR 1124 AND 1136). THOSE DEFICIENCIES ARE\r\n 9 ; CORRECTED IN THE SOURCE CODE BELOW.\r\n 10 ;\r\n 11 ; NOTE THAT CORRECTING THE DEFICIENCY AT 1124 (SO THAT\r\n 12 ; 1024 BYTES ARE LOADED, RATHER THAN 512) ALSO REQUIRES\r\n 13 ; THIS BOOTSTRAP TO BE RELOCATED TO ADDRESS 002000.\r\n 14 ;\r\n 15 ; MALCOLM MACLEOD - 11 JUNE 2017\r\n 16\r\n 17 000000 .ASECT\r\n 18 002000 .=002000\r\n 19\r\n 20 177170 RX2CS = 177170 ; RXV21 CONTROL\/STATUS REGISTER\r\n 21 177172 RX2DB = 177172 ; RXV21 DATA BUFFER REGISTER\r\n 22 000100 WRDCNT = ^D64 ; 128 FOR DBL-DEN, 64 FOR SGL-DEN\r\n 23 100240 MASK = 100240 ; BIT 15=ERR, 7=XFER-RQST, 5=DONE\r\n 24 002132 QUIT = GO-2 ; DEC HACK: BRANCHES TO A HALT\r\n 25\r\n 26 002000 012700 100240 MOV #MASK,R0 ; PUT BIT MASK INTO R0\r\n 27 002004 012701 177170 MOV #RX2CS,R1 ; PUT ADDR OF RX2CS INTO R1\r\n 28 002010 005002 CLR R2 ; CLEAR BUS ADDR (DMA DEST'N ADDR)\r\n 29 002012 012705 000100 MOV #WRDCNT,R5 ; PUT WORD COUNT (64) INTO R5\r\n 30 002016 012704 000401 MOV #401,R4 ; TRACK 1, SECTOR 1\r\n 31 002022 012703 177172 $1: MOV #RX2DB,R3 ; PUT ADDR OF RX2DB IN R3\r\n 32\r\n 33 ; CHECK THAT THE RXV21 IS READY\r\n 34\r\n 35 002026 030011 $2: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 36 002030 001776 BEQ $2 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 37 002032 100437 BMI QUIT ; HALT IF ERR IS SET\r\n 38\r\n 39 ; INITIATE A READ-SECTOR COMMAND\r\n 40\r\n 41 002034 012711 000007 MOV #7,(R1) ; DEN=SDEN, UNIT=0, FN=RD-SECTOR, GO\r\n 42 002040 030011 $3: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 43 002042 001776 BEQ $3 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 44 002044 100432 BMI QUIT ; HALT IF ERR IS SET\r\n 45 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 46 002046 110413 MOVB R4,(R3) ; WRITE SECTOR NUMBER TO RX2DB\r\n 47 002050 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 0-7\r\n 48 002052 030011 $4: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 49 002054 001776 BEQ $4 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 50 ; CODE ASSUMES THAT XFER-RQST (NOT ERR OR DONE) IS NOW SET\r\n 51 002056 110413 MOVB R4,(R3) ; WRITE TRACK NUMBER TO RX2DB\r\n 52\r\n 53 ; RXV21 IS NOW READING SECTOR DATA INTO ITS OWN BUFFER\r\n 54\r\n 55 002060 000304 SWAB R4 ; SWAP TRACK NUMBER TO BITS 15-8\r\n 56 002062 030011 $5: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 57 002064 001776 BEQ $5 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 58 002066 100421 BMI QUIT ; HALT IF ERR IS SET\r\n 59\r\n 60 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 61\r\n 62 ; THE SECTOR DATA IS NOW IN RXV21'S DATA BUFFER.\r\n 63 ; PREPARE TO TRANSFER SECTOR DATA FROM RXV21 TO RAM BY DMA\r\n 64\r\n 65 002070 012711 000003 MOV #3,(R1) ; DEN=SDEN, UNIT=ANY, FN=EMPTY-BUF, GO\r\n 66 002074 030011 $6: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 67 002076 001776 BEQ $6 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 68 002100 100414 BMI QUIT ; HALT IF ERR IS SET\r\n 69 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 70 002102 010513 MOV R5,(R3) ; LD WORD COUNT INTO RX2WC VIA RX2DB\r\n 71 002104 030011 $7: BIT R0,(R1) ; APPLY MASK TO RX2CS\r\n 72 002106 001776 BEQ $7 ; LOOP UNTIL ERR, XFER-RQST OR DONE\r\n 73 002110 100410 BMI QUIT ; HALT IF ERR IS SET\r\n 74 ; CODE ASSUMES THAT XFER-RQST IS NOW SET (IGNORES DONE)\r\n 75 002112 010213 MOV R2,(R3) ; LD BUS ADDRS INTO RX2BA VIA RX2DB\r\n 76\r\n 77 ; DATA (128 BYTES) IS NOW BEING COPIED TO RAM VIA DMA\r\n 78\r\n 79 002114 060502 ADD R5,R2 ; ADD 64 DEC TO BUS ADDRESS\r\n 80 002116 060502 ADD R5,R2 ; ADD 64 DEC TO BUS ADDRESS\r\n 81 002120 122424 CMPB (R4)+,(R4)+ ; INCREMENT SECTOR NUMBER BY 2\r\n 82 002122 120427 000017 CMPB R4,#17 ; ODD SECTORS D'01-D'15 WILL BE READ\r\n 83 002126 003735 BLE $1 ; LOOP BACK AND DO NEXT SECTOR\r\n 84 002130 012700 000000 MOV #0,R0 ; PUT UNIT NUMBER OF BOOT DRIVE IN R0\r\n 85 002134 005007 GO: CLR PC ; GO TO ADDR ZERO\r\n 86\r\n 87 000001 .END\r\n<\/pre>\n
General comments<\/h4>\n
My test environment<\/h4>\n
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Useful Resources<\/h4>\n