IBM 5100 Restoration in progress

On Wed, 18 Mar 2015, Santo Nucifora wrote: Sorry, there's a typo: .../ibm/ibm5110/... (instead of 5100). And use FTP as I said, so just change http:// with ftp:// or use a FTP client. BTW I had a look at your screen shot. The register contents is as follows: R0 - varying around $0090 R1 - $0090 R2 - $0000 R3 - $0600 R4 - $0006 R5 - $0202 R6 - $0005 R7 - $05C0 R8 - $00C0 R9..R14 - $0000 R15 - $0005 R13L1 - $7FFF (last RWS address? Do you have 32kB in your machine?) If your machine really halts at stop 'A', then this is strange. R5 should contain the screen address for the next character. $0202 should be for the 'C', so the machine might hang at stop 'B'. R15 should contain $00FF. Having R1 with $0090 implies a negative test instruction at $008C with the halt instruction at $008E. (R1 is used as link register with conditional skip instructions. If no skip occurs, the next instruction can be a jump to a subroutine, and R1 contains the address of the instruction following that jump. This is automatically done by the CPU). R3 and R4 might contain the end values after the screen clear routine (just before the 'A' routine). The 5110 version looks like this: ; Clear display 006C 8F40 LBI R15, #' ' 006E 0FFD MLH R15, R15 0070 8D06 LBI R13, #$06 0072 5F51 MOVE (R5)+, R15 0074 C5D7 SBSH R5, R13 0076 F005 BRA $0072 ; -> -$06(R0) And the 5100 version could be something like this: 8200 LBI R2, #' ' 022D MLH R2, R2 ; R2 <- $0000 8406 LBI R4, #$06 ; R4 <- $0006 5231 MOVE (R3)+, R2 C347 SBSH R3, R4 F005 BRA $-6 The screen is cleared from $0200 (begin of screen) up to (excluding) $0600 (end of screen). So R3 contains the address of the first byte after the screen area. But to find out what the machine did until this point, I need the Executable ROS hex dump as described in my last post. Address 0090 is well within the first 512 bytes so we should get the first couple of diagnostic routines. Christian