========================================== ******************************* * PART 7 - TECHNICAL FORUM * ******************************* TECHNICAL WRITES Although nobody has sent me a message about this query, a friend, who occasionally reads this magazine, has asked for an explanation of "hand-blocking", a method sometimes used to transfer old games to different media. Basically, it works like this: 1. Use a tape header reader to determine the start line of the first BASIC block, and the addresses and lengths of other blocks. 2. Reset the computer and MERGE the BASIC loader. After a pause, it should give OK. Programs larger than 7K may cause a system crash if they have been made MERGE proof. It should also be noted that all auto-run programs on Microdrives are MERGE proof. 3. Edit the LOAD statements so that they access the new device rather than the tape, including filenames. If a screen is loaded by LOAD ""CODE, change this to LOAD *"m";1;"filename"SCREEN$ (or LOAD "a:filename"SCREEN$, or whatever your device needs). Any block which passes through any of the addresses 23672 to 23674 needs its start address added after CODE. 4. SAVE the loader to the new medium. Remember the LINE parameter. 5. Reset the computer. Except for screens and blocks which pass through 23672 to 23674, LOAD further blocks to their original addresses, and SAVE them to the new medium from those addresses with their original lengths. Remember to CLEAR one byte below the start address first, unless the bytes load to the system variables or printer buffer. 6. Screens and frame-count-protect blocks (those which affect 23672 to 23674) need their contents preserved. CLEAR 32767 (25855 on a 16K) and LOAD the block to 32768 (25856 on 16K). SAVE it to the new medium from 32768 (or 25856) with its original length. 7. When all blocks are completed, reset the computer and LOAD the loader from the new medium. The game should start normally. Technical editor, Phil Reynolds, can be contacted by e-mail: phil@hedgford.demon.co.uk, or faxed (+44/0) 1543 428082. Technical queries will usually be answered in the next issue of Emulate. ==========================================