I'm having trouble trying to get running an old Apple ][ cassette program. I managed to successfully load the program into the Apple's memory, but it won't run. Here are the details: The program is 3-D Docking by Programma International circa 1978. The program's load address is $200 (hex) and it ranges to $2000 (the load command is 200.2000R). It somewhat cleverly is auto-running in that it loads directly into the Apple ][ keyboard buffer (which resides at $200), and at the exact spot where the load command "200.2000R" would normally end in the keyboard buffer, the command "220G" is "inserted" (overlaid really) by the load into the keyboard buffer. So when the ROM is done reading the program, it finds the next command in the keyboard buffer is "220G", so it will jump to the code at $220. This is where it is presumably supposed to initialize some stuff and then presumably run the game. This code first calls a routine in the BASIC ROM and then sets some zero page addresses, and then jumps into the BASIC ROM. However, it crashes with an "OVERFLOW ERROR" at the JSR to $F000 at $220. Here's the "init" code at $220: 0220- JSR $F000 0223- LDA #$AF 0225- STA $4A 0227- LDA #$0C 0229- STA $4B 022B- LDA #$00 022D- STA $4C 022F- LDA #$20 0231- STA $4D 0233- LDA #$9C 0235- STA $CA 0237- LDA #$11 0239- STA $CB 023B- LDA #$8F 023D- STA $CC 023F- LDA #$0D 0241- STA $CD 0243- JSR $FC58 0246- JMP $EFEC I have no idea what this is supposed to do. I've tried skipping the first JSR but that doesn't fix things. The actual code starts at $800. Starting at $800 sets graphics mode and clears hi-res page 1, but that's it. I so far haven't been able to find any other start address. And I so far haven't been able to figure out how it gets from $220 to the actual game code. I've tried this on an enhanced Apple //e as well as a stock Apple ][+ but get the same results. I also tried it in an emulator (AppleWin) under both //e and ][+ emulation and get the same results. If anyone wants to play with this, I put it up for download here: http://www.siconic.com/download/images/3DDOCK.DSK So if you're counting, that's: Cassette -> Apple //e -serial-> PC -network-> PC Server -internet-> Web server -> You! ;) Mount this volume into your emulator and boot from it. Then BLOAD the program THREE-D DOCKING ($200). The binary loads at $6000 (for obvious reasons, if you're an Apple nerd) so you must move it to its expected location: 200<6000.7E00M You can then examine the code at $220 and $800-$1FFF. If anyone figures out how to get this to run, please let me know ;) -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]