It still works. I use it. And anyone can build themselves a new one any time from my re-spin plans, it just hasn't changed and probably never will because I am not up to picking apart the firmware to hack on it nor write a new one. It's Steve's last version.
The only advancement is I made adapter boards for model 200 recently like I had for 100 & 102 already, where the board includes a copy of a standard rom so that it functions just like the original rom, but also provides a solderless connection out to rex and back so that you can boot from the rex or boot from internal without having to open the case again. And the connections are all dupont jumper wires, so installable/removable without soldering, and without blocking the original socket preventing having an internal main rom. Some weeks ago when we were talking about the weird 8k chip in the 200, I made a board for that. So now 200 also has this option to keep an internal rom and still boot from rex. For the main 32k chip in the 200, you just use the same one as 102. At the time we all decided based on the data sheets that if all you wanted to do was replace that 8k chip, you should be able to just use a normal 27C64, but I decided to actually implement the extra control pin with a few gates just to be sure. I have built and programmed that new board so I at least know the programing jumper setting works, but have not tried installing it yet. github.com/bkw777/aDIPters#flexrom_200_m13 It's kind of wildly impractical. These small eeprom are getting stupid expensive. I'm afraid to add up the cost of all the bits to make a rex classic and these two rom adapter boards to make a 200 with rex classic and still usable internal main rom. I mean I have already got all those bits, but I just mean I don't want to find out explicitly just how dumb it is. ;) But I do love my 100 and 102 with the same option. I switch between stock internal main rom with no rex, like when testing that ram+ or pgdesigns ram, rex classic software main rom, rexcpm, and back etc any time without opening the case any more. I love it. And it's all just sockets and dupont pin connectors. I could put the original stock rom back in any time. I could also ditch the jumper wires to rex yet still use the non-original main rom by just installing a jumper on the pins on the board in place of the wires. I could also still update the rom on the board. That would require opening the case again but no soldering. bkw On Sun, Feb 26, 2023, 12:46 AM Mike Stein <mhs.st...@gmail.com> wrote: > Yeah, the XR4 would certainly expand the options (pun intended) but I > never quite figured out how they selected among the images; I did work out > another solution and started building a 16MB RAM expansion but never > actually finished or tested any of it. Things like REX, the Backpack and > the Dial-a-ROM are a lot easier ;-) > > The issue is that when TS-DOS is in (the single) ROM space it would get > clobbered by loading another ROM image there; I'll have to have another > look at it all, including the EME tools, to see how it might work. Am I > missing something? > > BTW, I haven't used my REX in years; AFAIR it's the original version with > the System ROM replacement option and I guess there's not much support for > that these days? > > m > > On Sun, Feb 26, 2023 at 12:14 AM Stephen Adolph <twospru...@gmail.com> > wrote: > >> Mike, not sure I follow. >> You know you can have multiple ram spaces in option locations. Like xr4. >> Could an xr4 do what you want? >> >> Xr4 was a tidy solution. Needed a few wires to make it work. >> >> I guess I don't understand why tsdos is not compatible with option ram? >> Seems like it is, just like any other rom program? >> >> >> >> On Sunday, February 26, 2023, Mike Stein <mhs.st...@gmail.com> wrote: >> >>> As you may remember, years ago I designed an adapter that let you put >>> both the system image and an option ROM image into a single chip that >>> replaced the System ROM, both the standard (new) or non-standard (old) >>> version; some folks on here may even still have one in their M100, probably >>> loaded with TS-DOS. >>> >>> In another M100 I replaced the option ROM with RAM and load/save/copy >>> etc. various ROM images using the EME extRAM tools, but of course I can't >>> have TS-DOS in the same memory area as the option ROMs. >>> >>> The Dial-a-ROM and REX are certainly excellent solutions, but I'd still >>> like to make the Option RAM concept compatible with TS-DOS, even if I have >>> to add or reuse a physical switch to select between RAM and ROM. Any other >>> ideas? >>> >>> m >>> >>> >>> >>> On Sat, Feb 25, 2023 at 11:26 PM John R. Hogerhuis <jho...@pobox.com> >>> wrote: >>> >>>> >>>> >>>> On Sat, Feb 25, 2023, 8:18 PM Mike Stein <mhs.st...@gmail.com> wrote: >>>> >>>>> Yeah, I guess everybody has TS-DOS in ROM one way or another these >>>>> days; I've thought about putting it in the system ROM instead of the >>>>> Scheduler and Address Book, but removing them doesn't really free up much >>>>> space; maybe Teeny would fit... >>>>> >>>>> >>>> Scheduler and address book are a very simple "grep" type utility >>>> serving as a simple database. I feel they are too clever and minimalist a >>>> solution to remove :-) plus there are programs that let you use this search >>>> facility on any text file. >>>> >>>> -- John. >>>> >>>>> >>>>>
