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MEGA65 ROM Benchmark Results

  • Actually... no. The text referenced by Snoopy does not mention further statements after BEND at all, it only talks about "junk" as part of the BEND statement (like, before the next colon - what we talked about is what happens after the next colon).

    There is a difference in the behaviour of BEND depending of the block it is used.

    The BEND in the block after THEN searches for a following ELSE after the ":".

    The (second) BEND in the ELSE block behaves like a REM. All characters behind this BEND will be ignored and the program continue with the next program line.

    Edit: My first assumption was wrong. They are not being ignored at all. Only if the THEN case is true. After the ELSE case is true the commands after the BEND will be executed (see next post).


    The BEND at the end of an ELSE clause is effectively just like REM because BASIC will not search for another colon (:), but in general simply continue with the next line in the program.

  • Okay, I have tested it with the C128 VICE:

    It's like Bit Shifter described: The "HELLO" in line 120 was only printed if the ELSE case was true. If the THEN case is true, the "HELLO" will be ignored although it stands behind the (second) BEND in line 120.

    It makes no sense, because the PRINT"HELLO" is no part of the ELSE block.

    So I would call this a bug! ;)

  • Just for info: I just uploaded the benchmark disk image also at the MEGA65 filehost.

    Very nice. Thanks alot Snoopy

  • Here is the result of your BENCH01-INT running on a 1 MHz C64 (VICE x64 3.1 Linux Lite 4.8) with BBC BASIC II:



    Because I was curious about:

    The BBC BASIC V of the Archimedes (8 MHz) needs 0.26 seconds for BENCH01-INT ... :D:weg:

    Okay, okay, I go to bed now ... :D

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  • Because Bit Shifter had decided not to sleep anymore, there is an daily update of the new ROM. ;)

    So I thought it would be a good idea, to test how the BASIC 10 speed is influenced by this continuous development. :loet

    The first problem with this benchmark test was, that my Nexys board wouldn't run the latest MEGA ROM. :cry:

    Okay, this problem could be solved very quickly with the help of the team: I used a "very old" bitstream. So I get a current bitstream (from February 3, 2021) and with it the new ROM runs great on my Nexys board.

    To be quite fair, I run all test again with this new bitstream. I want to use exactly the same "hardware" while testing this three ROMs:

    - 911210 - the latest ROM from Commodore

    - 920116 - the MEGA ROM used at the first test

    - 920127 - the latest MEGA ROM (at least until - I guess - tomorrow ...) ;)

    The test results in seconds are in the first column for the 911210, in the second for the 920116 and in the third for the 920127. In the first raw are the result for the 3,5 Mhz mode and in the second for the 40 MHz mode (for each benchmark).

    The last three hold the % comparison to the 911210 and (in the last column) the 920127 to the 920116 (+ menas faster, - means slower).

    With the new bitstream BENCH07 also works with the 920116, so I can get results for it now.

    Here some thoughts about this new test:

    First, the newer bitstream accelerated even the 911210 a little bit, so the results are a little faster compared to the first test (with the older bitstream). But this is just a side note, I want to test the speed of the ROMs compared to each other.

    The newest ROM takes really off (about 50% faster) compared to the 920116 in benchmark 03 and 04 (the ones with the sin and cos). 8o

    There are some benchmarks in which the 920127 is slightly slower as the 920116, but not very much (1% to 3%).

    Thanks again Bit Shifter for his persistent work with the ROM! It's a great speed booster, especially compared to the 911210! :thumbup:

  • Hello Snoopy !

    Thanks alot for your benchmark tests again !
    You won't believe, how valuable this information is for us ! Thanks a 1000 times, that you invest your own time helping us !!!
    DANKE !!!
    Your BENCH03 and BENCH04 test results are amazing. WOW ! (here the thanks goes to Bit Shifter ! incredible work)
    This difference in speed is definetely reckognisable in BASIC.
    Whenever i've been asked, what ROM should they use, i always answer the following:
    you got three options:
    - use the orginal last official Commodore C65 Kernel ROM 911210 (i prefer the LED and Checksum patched) version :-D
    - use the (picked up where Commodore wrapped it up and go from there) MEGA65.ROM (92XXXX) version in constant development by Bit Shifter .
    - use the OpenROM version (fully Open Source freely distributable and in constant Devolpment.) Her my huge thanks goes to FeralChild THANKS !!!)

    So, please continue and let us know about everything you notice. Thanks !

    with best regards,


    PS: Vergiss nicht, deinen Kaktus zu gießen ! (2.Warnung !) :-D

  • Open ROMs will end up with ?NOT IMPLEMENTED ERROR (or ?SYNTAX ERROR if BASIC 10 tokens are used). It does not even have floating point (or integer) variables support at this moment - since my work on string variables and arrays last year, I have focused on other areas, right now I'm working on CP/M support (definitely won't be finished until Hyper RAM is stable) and some minimal internal DOS for loading files from SD card.

    But once Paul finishes the IEC fix, and I enable the JiffyDOS support on MEGA65 build, you will be welcome to benchmark the drive performance :D

  • Hi Snoopy !

    Would you be interested implementing the following Benchmark test: "try the duration of the RENUMBER command" in your test cycle ?

    And also, what i am interested in, does the MEGA65 BASIC still "feels" Commodore ? - Your honest opinion please !
    (may we quote you ? )

    With best regards,


    PS: Yes, confirmed, your cactus counts as watered, thanks for the cooperative, time saving solution.you'll get 5 minutes added to your sleep time :-D

  • Would you be interested implementing the following Benchmark test: "try the duration of the RENUMBER command" in your test cycle ?

    Yes, no problem. I will get a RENUMBER test into the next benchmark session. :)

    And also, what i am interested in, does the MEGA65 BASIC still "feels" Commodore ? - Your honest opinion please !
    (may we quote you ? )

    Says the boss at the beginning of the meeting:

    First the bad news: Due to financial bottlenecks, we unfortunately have to lay off at least one employee at the end of the month.

    But now for the good news: You can now honestly say what you think about our project! ... :D

    Okay, even if I will probably be able to drive home without a cactus afterwards, my very personal opinion on the new ROMs:

    No, they don't feel like "Commodore" to me anymore. For me it starts with the fact that they wouldn't run on a C65 like that. You can try this out yourself with the C65 emulator (xc65).

    It is clearly a ROM that absolutely requires the MEGA65 and its hardware extensions. This is also not surprising, since it is being developed further precisely for this purpose, to be able to use the MEGA65 extensions better.

    As an example it is already very "time-saving" if you only have to type the "$" key for the DIRECTORY or only the "/" symbol for loading, as in the new ROM, but it is not a "Commodore" command. At least I don't know that such abbreviations were planned for it.

    Even if I'm probably more alone with that, but personally I'm mainly interested in the MEGA65 project in the C65, which I couldn't have at that time. And exactly like that. I'm interested in the "Commodore" in it.

    All the extensions that the MEGA65 offers compared to the C65 are technically interesting, but - without making it sound derogatory - not a development by Commodore, but thoughts and developments of the MEGA team in modern times (the last few years). From a purely historical point of view, this is as interesting to me as a replica of the Limes to which cannons are attached so that the defenses against the advancing barbarians are "better". ;)

    Again: That should in no way detract from the excellent performance of the team! Without the MEGA65 project and all the "trimmings" such as the great emulators from LGB-Z , I would never have had the opportunity to deal so intensively with the C65 and its ROMs. For that alone I am eternally grateful to the whole team! :thumbup:

    But to get back to your question:

    The new ROMs are no longer "Commodore" for me, but "Bit Shifter" or "MEGA team" ROMs. That's what they should and want to be. So everything is okay!

    I myself use the latest, freshly baked 92.... ROMs for testing and benchmarks. I want to see what has happened to the development. :)

    However, when I sit on the Nexys board or the emulator "for myself" and do something with it, then I have the 911210 ROM in it. Simply because it is still the "original Commodore C65" and that is important to me personally - as described above - on the C65.

    If you still like to do, feel free to quote me where ever you want. :)

    Thank you for your honest opinion, the boss said before he signed the dismissal.... :whistling:

  • Thank you for your open words Snoopy . We have indeed overcome the point of maximum emotions caused by nostalgia. While we still are keen on keeping those to the ones who prefer to stay strictly Commodore, there is too much to make better and yet to discovered for us. We have taken on the challenge to do the triple balancing act to make an as good as possible yet modernized C64, C65 AND our reinterprtation/continuation MEGA65 at once. This is the reason why it takes us so long to deliver something we can call finished and complete, even with all the helping hands and great minds involved. Being in the 6th year of development now, we are happy to say we see the light at the end of the tunnel, it has been and still is a great fun ride - and the biggest nerd experience all of us can think of :)

    Keep doing what you're good at - all of you. Whether you put on your C64, C65 or MEGA goggles :D



  • These are interesting questions. However as far as I feel, even if it's not the "open-rom" with all the own goodies it's already not "pure c65" ROM, ie using MEGA65 extensions to work, and would not work on a C65. For example, direct manipulating bitplanes are not possible in the C65-compatible way, since those are in bank4/5 now, which is not possible on C65 (and thus meaning some problem if a program directly want to access bitplanes in the memory bypassing BASIC routines to draw etc). Also, kind of "dos wedges" were common even in the C64 era (though indeed, not "original Commodore" things). That's however a good question if there can be a "pure C65 ROM" would work even on a C65 "only" with fixing some of the bugs, and unimplemented details of the original ROM. I can't answer this, but as far as I feel, it's maybe too much to ask, nobody has that amount of time to take care "only-C65" versions when the all project is about MEGA65. But I can be wrong, and I don't mind here at all if I am wrong ;)

  • Hi Snoopy ,

    i've asked for an honest opinion and i've expected to receive it from you. Thank you very much !

    i believe deft summarized it perfectly. It's a fun and wild ride and we invite every Retro 8-bit fan to join.

    We believe, with the MEGA65 project there is so much to discover and to experience, there is a certain topic for everybody.

  • We have taken on the challenge to do the triple balancing act to make an as good as possible yet modernized C64, C65 AND our reinterprtation/continuation MEGA65 at once

    That is one of the good thing about the MEGA65: It can be used as what ever you want. :thumbup:

    As long as it can be used as a C65 with the original ROMs from Commodore, I will be happy forever. Who needs 8MB RAM? 1MB is still more than enough. :D

    Just to make sure that I am not misunderstood:

    The MEGA65 with its extensions is technically interesting and a ROM adapted to it is more than necessary to make these extensions comfortably usable under BASIC. And here the successes so far are very good and the increase in speed is enormous. :thumbup:

    I would just make myself very aware that it is no longer a Commodore ROM and, above all, shouldn't be one anymore. It is a MEGA65 ROM that breaks away from its origin C65 and begins to stand on own legs. Commit it the "next generation"! And this should and must bring enough of its own that it is deliberately no longer a Commodore.

    In this respect, I see it all very positively and look forward to further progress with the MEGA65 ROM! :thumbup:

    And I love my cactus ... :love:

  • To me a DOS Wedge is a Commodore thing, it just didn’t get into the ROM. Just look at the content of the disk that came with your 1541 :)

    I know the DOS Wedge from 1982. It's a nice addon like Simon's BASIC or other nice tools for the C64. :)

    But I'm pretty sure, Commodore would had put it into the ROM (at the latest in the C128 one), if they wanted it to be a part of the ROM. ;)

  • In my opinion Commodore did not do so many clever things (ducks: blasphemy!) except producing the C64 and later buying AMIGA. The decades have gone by and we only have a fragment of those engineers, marketeers, managers etc., thus the MEGA65 won't be another C64 or AMIGA. But it's most probably be the best we all can get to resurrect bits of this time and float in nostalgia :)



    admin: please delete this post in case you see people with torches and dung forks in front of your house!

  • Just to ad some noise here: Personally I love the concept of having different (all 3) ROM variants for the MEGA. The original C65, because if the C65 would have been released, I most likely I would have got one, so thats a must have for me. The improved/fixed version is still useful, because yeah, who really likes bugs? And the open-rom is the way forward and needed for legal reasons anyway, AFAIU.

    So all of them have a very good reason to exist, at least for me. GO MEGA.