Hi Jeff. That's a fancy little unit! Great functionality for such an inexpensive device.
One quick note about your TS-DOS uninstall portion: In the TS-DOS screen, the key label on F5 shows the actual current state, not what pressing the key would change it to. When you see "DOS-OFF", it means the DOS is unhooked. Pressing it so that it changes to DOS-ON actually means you've just hooked it into memory. You can verify the truth of my statement by having it show the "DOS-ON" status, and then drop into BASIC and type LFILES when you have a Backpack hooked up. On Sun, Feb 26, 2023 at 12:03 PM Brian K. White <[email protected]> wrote: > On 2/26/23 12:16, Mike Stein wrote: > > Ah, got it; I was asking about switching it from the keyboard as the XR4 > > does, not a physical switch. > > > > But if you're just talking about a small number of selections then tiny > > diodes would probably work just as well and not require any power. > > I guess you're right, since it's only OR gates and positive logic, those > could just as well be common cathode pairs of diodes, and they are > available in a single 6-pin package, and it needs one fewer resistors > because instead of pulling down the 3 inputs, you pull down the two > outputs, though that doesn't really save me anything because I'm using a > single 4-resistor part. > > It doesn't save much in absolute terms, like cost or real estate, but it > still does remove a bit of power and trace routing and trades a fancier > part for a more common and basic part. > > I'll try it. > > > > m > > > > On Sun, Feb 26, 2023 at 9:52 AM Brian K. White <[email protected] > > <mailto:[email protected]>> wrote: > > > > On 2/26/23 08:23, Stephen Adolph wrote: > > > Brian, If I understand your comment, I don't think you need an IC > > to do > > > rom selection. I think the DAR uses a rotary encoder. > > > > I understand that the dar uses a rotary encoder. > > The slide switch needs the extra glue. > > > > I was responding to Mike's question "how does the bank select work?" > > answer: gratuitous extra parts because I just wanted a slide switch. > > > > > > > When I first saw the DAR, I wondered about that. I'm pretty sure > > I found > > > the part at Digikey. Very good! > > > Steve > > > > > > On Sun, Feb 26, 2023 at 3:51 AM Brian White <[email protected] > > <mailto:[email protected]> > > > <mailto:[email protected] <mailto:[email protected]>>> > wrote: > > > > > > Gratuitous use of another chip just for 2 OR gates to > implement a > > > 4:2 encoder. It's all less efficient and less practical than > the > > > dial-a-rom, in that the dar holds 16 roms and doesn't need > > another > > > ic, and the dar programming connection is even simpler and > > more robust. > > > > > > But it just amused me to have a direct selector without > manually > > > binary encoding dip switches because why not? And I didn't > > want it > > > to require a tool to use either like a screwdriver. And of > > course I > > > always want an open source option, and I'm not up to the task > of > > > coming up with an open source rex-alike but using a Lattice > > part and > > > the open source toolchain. > > > > > > It's unfortunate timing but I had already started this at > least 3 > > > years ago but just never finished it. A non-working version > > has been > > > sitting in that github since 2019. A few weeks ago I finally > > dusted > > > it off and corrected my bonehead pinout error, dialled-in the > > > programming connection so it works well (the holes are > slightly > > > closer together than the pins, and the pattern and amount of > > offset > > > took some trial & error) and replaced dip switches with the > slide > > > switch & or gates. I had no idea the dar was in the works. > > Not that > > > it would have stopped me, but I just mean to say this isn't a > > reaction. > > > > > > It's no competition anyway because only a very few people > > ever build > > > these diy-only things. I want them to exist so the option is > > there, > > > but almost no one actually employs it. So this is not touching > > > anyone's sales. Besides, *16* roms. And of course really it's > > even > > > sillier when rex exists which doesn't even need a programmer > or > > > adapter to load it's, what, 30? slots? But for other > > platforms 4 is > > > plenty. There's only 2 roms total for the 600 for example. > Still > > > leaves 2 free slots for hacking. > > > > > > I just added the browser-friendly render of the schematic to > the > > > readme so you can see the bank-select. > > > > > > -- > > > bkw > > > > > > On Sat, Feb 25, 2023, 8:18 PM Mike Stein <[email protected] > > <mailto:[email protected]> > > > <mailto:[email protected] <mailto:[email protected]>>> > wrote: > > > > > > How do you select among the 4 images? > > > > > > On Sat, Feb 25, 2023 at 6:50 PM Brian K. White > > > <[email protected] <mailto:[email protected]> > > <mailto:[email protected] <mailto:[email protected]>>> wrote: > > > > > > On 2/25/23 10:31, [email protected] > > <mailto:[email protected]> > > > <mailto:[email protected] > > <mailto:[email protected]>> wrote: > > > > Morning all, > > > > > > > > I just made this video live this AM. The DARs for > the > > > Model T computers > > > > have sold out already but my friend is making more. > > > > > > > > In this video we take a look at the ‘Dial-A-ROM’ a > > spiffy > > > new multi-ROM > > > > for vintage portable computers. It was designed by > the > > > same guy who did > > > > the Backpack drive. First, we’ll learn how to use > the > > > Dial-A-ROM with > > > > the ROM images that come preinstalled on it. Then > > we’ll > > > see how to add > > > > our own ROM images if we so desire. > > > > > > > > *https://youtu.be/CejyLsI0HIw > > <https://youtu.be/CejyLsI0HIw> > > > <https://youtu.be/CejyLsI0HIw > > <https://youtu.be/CejyLsI0HIw>> <https://youtu.be/CejyLsI0HIw > > <https://youtu.be/CejyLsI0HIw> > > > <https://youtu.be/CejyLsI0HIw > > <https://youtu.be/CejyLsI0HIw>>> > > > > > > > > Jeff Birt (Hey Birt!)* > > > > > > > > > > And for the diy-er, I finally vetted these last week: > > > https://github.com/bkw777/Teeprom/blob/master/4ROM.md > > <https://github.com/bkw777/Teeprom/blob/master/4ROM.md> > > > > > <https://github.com/bkw777/Teeprom/blob/master/4ROM.md > > <https://github.com/bkw777/Teeprom/blob/master/4ROM.md>> > > > > > > -- > > > bkw > > > > > > > -- > > bkw > > > > -- > bkw > >
