@ @ Use the S3 compiler (see Steve Hammond's S3 example) to create an @ "empty" module. @ S3_COMPILE(,*OMF.) ---- MODULE NNBBW GLOBAL STATIC () PROC NNBBW IS () : BEGIN END; ENDMODULE ++++ @ @ Now use Fujitsu's AMENDMODULE utility to patch the module. @ AMENDMODULE(*OMF.NNBBW) ---- @ @ First, create an external reference to the message logger which @ displays output to the screen. @ CREATE_REFERENCE(SENDMESSAGE) @ @ Now patch the external reference into the Procedure Linkage Table. @ POINT(NNBBW.NNBBW_LT) PATCH( NAME = NNBBW_LT V1/0 , JUMP = NO , DISPLACEMENT = X00 , TO = CODE !A %SENDMESSAGE END ) @ @ Finally, write the module. This is a map of our stack usage: @ @ 03 - CHAR: A single character to be strung into BUFFER. @ 04 - Our PLT base address. @ 05-06 - WBUFF_DESC: Descriptor to WBUFFER. @ 07-08 - NBUFF_DESC: Descriptor to NBUFFER. @ 09-0A - CHAR_DESC: Descriptor to 4th byte of CHAR. @ 0B - WBUFF_POS: Word (current position within WBUFFER). @ 0C - BOTTLES: Word (descending count of bottles). @ 0D... - NBUFFER: 15 bytes used for numeric conversion. @ 13... - WBUFFER: 256 bytes used to construct lines for logging. @ POINT(NNBBW.NNBBW_C) PATCH( NAME = NNBBW_C V1/0 , JUMP = YES , RETURN = NO , DISPLACEMENT = X00 , TO = CODE * * Initial actions. We prime our three on-stack descriptors and * set WBUFF_POS and BOTTLES to their initial values. * STD.L X03 * Store our PLT descriptor (addr. part to X04) STLN.B * Store our local name base in BREG ASF X60 * Claim stack space LSS.B * Get LNB into the accumulator LUH X00 * ACC to size 64 bits IAD.P N * Complete the descriptor to NBUFFER ST.L X07 * Store NBUFF_DESC LSS.B * Get LNB again LUH X00 * ACC to size 64 bits IAD.P O * Complete the descriptor to WBUFFER ST.L X05 * Store WBUFF_DESC LSS.B * Get LNB again LUH X00 * ACC to size 64 bits IAD.P M * Complete the descriptor to CHAR ST.L X09 * Store CHAR_DESC LSD X63 * Set ACC to 99 ST.L X0B * Set WBUFF_POS to zero and BOTTLES to 99 * * This is the main processing loop, exited when BOTTLES reaches * zero. * A LSS.L X0C * Fetch BOTTLES JZ F * Jump on if zero JLK J * Convert to numeric and store JLK G * Call the handler for " bottle(s) of beer" LDRL.P W * Load " on the wall" JLK K * Store it LSS X6B * Load "," JLK I * Store it LSS X40 * Load " " JLK I * LSS.L X0C * Fetch BOTTLES again JLK J * JLK G * Call the handler for " bottle(s) of beer" LSS X4B * Load "." JLK I JLK L * Log it LDRL.P Z * Load "Take one down and pass it around, " JLK K * Store it LSS.L X0C * Get bottles USB X01 * Decrement it ST.L X0C * Update the stored value JZ C * Jump on if zero JLK J * J D * Jump on C LSS X95 * "n" JLK I * Store it LDRL.P X * Load "o more" JLK K * Store it D JLK G * Call the handler for " bottle(s) of beer" LDRL.P W * Load " on the wall" JLK K LSS X4B * Load "." JLK I JLK L * Log it LSS X40 * Load " " JLK I JLK L * Log a blank line J A * Back around the main processing loop F * * We come here when BOTTLES has reached zero. * LSS XD5 * Load "N" JLK I LDRL.P X * Load "o more" JLK K JLK G * Call the handler for " bottle(s) of beer" LDRL.P W * Load " on the wall" JLK K LSS X6B * Load "," JLK I LSS X40 * Load " " JLK I LSS X95 * Load "n" JLK I LDRL.P X * Load "o more" JLK K JLK G * Call the handler for " bottle(s) of beer" LSS X4B * Load "." JLK I JLK L * Log it LDRL.P Y * Load "Go to the store and buy some more, " JLK K LSS X63 * Set 99 JLK J JLK G * Call the handler for " bottle(s) of beer" LDRL.P W * Load " on the wall" JLK K LSS X4B * Load "." JLK I JLK L * Log the final line EXIT X00 * Done G * * This subroutine manages the storing of the either * " bottle of beer" or " bottles of beer", depending on the * value of BOTTLES. * LDRL.P U * Load " bottle" JLK K * Store it LSS.L X0C * Load BOTTLES UCP X01 * Is it 1? JE H * Jump on if so LSS XA2 * Load "s" JLK I * Store it H LDRL.P V * Load " of beer" JLK K J.T * Exit from subroutine I * * This subroutine manages the adding of a single character in * the accumulator to the buffer. * ST.L X03 * Store the character in CHAR LD.L X09 * Prime DR with CHAR_DESC J K * Jump on to the stringing routine J * * This subroutine converts the value of the accumulator (which * contains the current value of BOTTLES) to a printable format * with leading zeros suppressed, leaving the result in DR. It * then drops through into the following stringing routine. * Note that it is not called to handle zero. * CDEC * Convert to packed decimal format LD.L X07 * Prime DR with NBUFF_DESC MPSR X24 * Set the condition codes to 1 SUPK * Unpack to printable characters LD.L X07 * Get NBUFF_DESC again SWEQ X00,C'0' * Suppress leading zeros, drop through K * * This subroutine strings the contents of DR into WBUFFER, * updating WBUFF_POS in the process. * STD.T * Stack DR LSS.T * Drop the address part LSS.T * Fetch Type and Bound AND XFF * Mask out the Type ST.B * Into BREG with the length CYD * Copy DR to ACC LD.L X05 * Fetch WBUFF_DESC MODD.L X0B * Drop the portion up to WBUFF_POS LDB.B * Set the bound MV * Move the data into WBUFFER LSS.L X0B * Get WBUFF_POS UAD.B * Add in the length of the string ST.L X0B * Store updated WBUFF_POS J.T * Exit from subroutine. L * * This subroutine calls SEND_MESSAGE to log the current line, * after which the buffer pointer is reset, ready for the next * line. * LXN.L X04 * Set XNB (only need it in this one place) PRCL X04 * Prepare for the call LD.L X05 * Get WBUFFER LDB.L X0B * Set the bound to WBUFF_POS STD.T * Store the descriptor at TOS RALN X07 * Raise LNB - two words of parameter space CALL.IX !A * Call SEND_MESSAGE LSS X00 * Set zero ST.L X0B * Reset WBUFF_POS J.T * Exit from subroutine * * Declare literal data, starting with three "skeleton" * descriptors used during initialisation. There then * follow a series of string "fragments" which are * stitched together at run-time. * ALIGN 1 M X18000001 0000000F * Outline descriptor to CHAR N X1800000F 00000034 * Outline descriptor to NBUFFER O X18000100 0000004C * Outline descriptor to WBUFFER U X1800000700000008 C' bottle' ALIGN 1 V X1800000800000008 C' of beer' ALIGN 1 W X1800000C00000008 C' on the wall' ALIGN 1 X X1800000600000008 C'o more' ALIGN 1 Y X1800002300000008 C'Go to the store and buy some more, ' ALIGN 1 Z X1800002200000008 C'Take one down and pass it around, ' END ) ++++