[HN Gopher] Patching 68K Software - SimpleText
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       Patching 68K Software - SimpleText
        
       Author : mmoogle
       Score  : 96 points
       Date   : 2025-11-04 22:59 UTC (1 days ago)
        
 (HTM) web link (tinkerdifferent.com)
 (TXT) w3m dump (tinkerdifferent.com)
        
       | mjg59 wrote:
       | This is beautiful, but the real takeaway should be that even
       | proprietary software you only have binaries for is still mutable.
       | The computer runs the code you want it to run. We always need to
       | maintain that and prevent scenarios where general purpose
       | computers stop being the default.
        
         | LennyHenrysNuts wrote:
         | We were always doing this kind of thing on these platforms.
         | This is how we used to hack copy protection out of games.
         | 
         | Stepping through, line by line, editing the code and adding
         | JMPs to get around the copy protection code after loading the
         | magic numbers into the register...
         | 
         | Happy, happy times.
        
           | classichasclass wrote:
           | Then they started loading the protection code from disk doing
           | tricky things. One I cracked recently was a pair of Commodore
           | 1541 sectors that appeared to be the same logical sector
           | (because the drive head is blind). It needed to hit both of
           | them to compile the next portion of the loader. Naturally the
           | segment up to that point was encrypted as well, but nothing
           | survives a VICE breakpoint.
           | https://oldvcr.blogspot.com/2023/08/cracking-designwares-
           | gra...
           | 
           | Obviously this is nothing on things like V-MAX! and Rapidlok
           | which even nowadays have variations that are tough to
           | remaster.
        
           | a96 wrote:
           | That's how I first learned assembly. Armed with a monitor
           | program that can disassemble and modify memory, I read and
           | modified programs stepping through them. Mostly games,
           | naturally. I never got an actual assembler/linker chain that
           | would work and useful software was hard to come by.
        
         | userbinator wrote:
         | Unfortunately the whole "open source" movement has diverted
         | attention away from that and brainwashed countless would-be
         | power-users and even developers into believing that they are
         | powerless to do anything without the source code. It's
         | convenient to have the source, but not necessary for freedom.
        
         | disruptiveink wrote:
         | Cat's out of the bag there already. We all have general purpose
         | computing devices in our pockets, locked down on purpose.
         | Android used to allow you to gain admin rights but it's been
         | getting more and more impossible to do so while still keeping
         | most of your programs working. It's not only a cat-and-mouse
         | game against "rooting detection" SDKs companies licence and
         | plug into their apps out of a misguided duty of care, but it's
         | especially bad with anything that uses Google's remote
         | attestation lately.
         | 
         | Android is also about to lock down "sideloading", another
         | "great" dysphemism for "installing software".
         | 
         | Moving the Overton window on this has been so successful, that
         | even people in our industry happily accepted the much maligned
         | dysphemisms of "jailbreaking" and "rooting" for what used to be
         | called "local admin rights" and look upon such access as if
         | it's only something pirates, criminals or malware spreaders
         | would want to do.
         | 
         | I say this as someone who is running an Android phone with a
         | kernel with some backported patches applied and compiled by
         | myself. The fact that I can do it is great. The fact that the
         | entire industry is trying to make it as frustrating as possible
         | for me to do this under the guise of false premises such as
         | "security" is disheartening.
        
         | ErroneousBosh wrote:
         | > even proprietary software you only have binaries for is still
         | mutable
         | 
         | POKE 35136, 0
         | 
         | thus it ever was.
        
       | musicale wrote:
       | I thought option-resize was supposed to resize the default (new
       | document) window?
       | 
       | My recent pet peeve is that macOS doesn't seem to remember window
       | sizes and locations properly. Things are certainly complicated by
       | multi-monitor setups, but it seems like some sensible default
       | behavior could be implemented.
       | 
       | I don't dislike the column browser, but I wish macOS would
       | preserve/revive its spatial UI in both the Finder and document
       | window positions.
        
         | chongli wrote:
         | I really miss the spatial classic Mac OS too. I don't think
         | spatial orientation will ever come back to the Mac. Apple seems
         | to have moved on completely.
         | 
         | In some ways, the world has moved on as well. Spatial
         | orientation worked really well when the number of files and
         | folders we typically dealt with was fairly small in number. Now
         | we tend to deal with huge numbers of files, most of which
         | aren't even on our local computer. It's hard for me to imagine
         | how a spatial system like that could be made to work with all
         | of that. What would a "spatial Wikipedia" look like?
        
       | girl2 wrote:
       | I had to do this at work once
        
       | robinhouston wrote:
       | I used to love doing this sort of thing back in the early '90s.
       | What a nostalgic read! Funny that there are still people doing it
       | today.
        
       | unwind wrote:
       | For people not used to reading MC8k assembly [1], it's helpful to
       | point out the basic fact that the syntax is in general
       | opcode  source, destination
       | 
       | which is the other way around from most contemporary ISA:s. So a
       | line like                   move.l d0, -(a7)
       | 
       | will first decrement the value of register a7, then write the
       | contents of register d0 to the resulting address (it's a "push"
       | for a downwards-growing stack).
       | 
       | Edit: added Wiki-linkage.
       | 
       | [1]:
       | https://en.wikipedia.org/wiki/Motorola_68000#Instruction_set...
        
         | marssaxman wrote:
         | 68K style always made more sense to me: we read left-to-right,
         | after all. Why should we suddenly switch directions for the
         | operand order? It's confusing.
        
       | TomMasz wrote:
       | I fondly remember patching 68K code in memory on an industrial
       | control system my company was developing. I was able to decode
       | the instructions just by looking at the hex display. Daresay, I
       | could not do that with any modern system.
        
         | Zigurd wrote:
         | The first assembler I had to look at was PDP-11 code. 68k is
         | kind of like a 32 bit PDP-11, easy to see what's happening. One
         | of my very first paid tech jobs was maintaining an ST506 driver
         | written in 68k asm by game hackers using self modifying code
         | for no specific reason other than that's how they roll.
        
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       (page generated 2025-11-05 23:02 UTC)