Post by feedingdragon on Jul 26, 2019 14:32:57 GMT
2 questions, actually.
1) In researching, I found only a single place that mentions using the GEOS128 boot ROM in the external function slot (REU 1750.) It stated that the ROMs available will all work if a single byte is changed, but does not say which byte, or what it needs to be changed from/to. Further searches have failed to show me the answer, and I'd prefer not to try to figure it out myself (hate disassembling code to figure things like that out, sorry.) I will if I have to, but I'm hoping someone already has the answer.
2) Since I'm installing this in a 128, has anyone ever considered altering the C64 GEOS boot ROM to copy itself to 64 mode RAM, then switch to 64 mode? You have 16k of programming space to accomplish this, and it seems like it should be fairly easy to do. May even allow the stock configure utility to work (as the GEOS code is now in RAM instead of ROM, so switching the bank from ROM to RAM should no longer hurt anything. Actually planning to work on this myself, though it will involve learning a lot more about the 128 than I know now. Only ever really did any programming on my 64 back in the day. When I got a 128, the only programming I did was for 64 mode.
Post by feedingdragon on Aug 18, 2019 13:18:05 GMT
Well got a working prototype of a C64 GEOS ROM that will Switch a C128 to 64 mode, then start itself up. It has the advantage of detecting the drive type in use (1541, 1571, or 1581) and installing the appropriate part of the GEOS floppy driver, and even asking which drive to boot from (if it doesn't find the DeskTop in drive 8 that is.) Can change the default drive from 8 by using a hex editor to change the value at x8eff from x08 to x09 or x0a. I couldn't get GEOS to load up on any other drive numbers.
Still working on it, mainly because my programming is rather crude and clunky But also because setting drive 10 (x0a) and it refuses to work 100%. It will boot up with a 1581 drive there (which is what I used for all my testing: 8-1541, 9-1571, 10-1581.) But you can never add the other drives. You can add them, but they won't show up. Putting 1581 into any other slot (8 or 9,) and they still don't show up after boot, but you can manually add them without any issue. Booting to 1541 or 1571 in either slot (8 or 9,) and it will detect the other drives and add them automatically. Unless, I'm assuming, you have settings disabling them in favor of RAM or what-not. Been to long since I worked with GEOS, and when I did, I din't have a REU, just 3 1541 drives. Never tried booting other than drive 8 back then either. I really only used GEOS for some productivity software, back in the day, as well.
I used the freely downloadable version 2.1 from the web to build this, and spent a lot of time making it look pretty Still waiting on some parts to finish modding my 128, but I'll check it on real HW when I get that finished. Been using Vice for testing for now. If anyone has the equipment and want to test it on real HW, I look forward to any results you get. For now, if I don't figure out what is up with drive 10, I'm going to remove it from the options. Also hoping to figure out what's up with the 1581 device (it won't auto-detect the other drives.) Probably going to involve disassembling the driver code and working out what that does. I hate tracing code like that I'm not "exceptionally" worried about it, as the problem persists even if I use the pure disks (created through the same download site,) to load up normally.
OK, may be a dead cause. Minor issues I had hoped to fix, or even remove planned options to make a more pure transfer, seem to be unfixable. Cannot seem to write to disks reliably in GEOS, but the problem remains even when running a pure form from the disk. Problem goes away if I switch from VICE128 in 64 mode to VICE64. So, am wondering if that's a VICE thing or something my real 128 will face. I know that VICE128 has problems with either burst mode, or turning off burst mode (will have to look that up,) which is why I've had problems running some things in VICE in the past (that ended up working fine on my real HW.)
Anyway. Anyone with a physical system (and the means to put the ROM on an EPROM,) willing to test what I've put up and let me know if the problem persists with real HW or just VICE? It would be appreciated. I'll test it myself once my 128 is back up & running again. But would sort of like to get to working on it again if I can/should.
Post by feedingdragon on Aug 20, 2019 23:40:50 GMT
Turns out the problem exists on real HW whether I run from floppy or use my ROM. Cannot write to disks, and lose disk drives on a regular basis. So, GEOS64 won't run on a 128 in 64 mode it seems Oh well. Guess I'm stuck with just GEOS128. Onward to trying to figure out why the GEOS128 ROM cannot be run from External Function ROM. Not that it makes a difference any more. I'm back down to only 2 things I have that actually work, and I would like to install. Since I'm using 128k EEPROMs, I can put those on the internal Function ROM and just worry about the External one when/if I find 2 more I'd like to use.