Put core on rom?

[David Nelson]

I was going about lining up yet another project for me to eventually get to. This time it was diving into the world of EPROM programming. I'd snapped up one of those 1581 kits and sourced an Amiga Chinon floppy for it. The floppies arrived (one for the 1581, and one to replace a dying floppy in my A4000). The kit should arrive this week. From the cbm newsgroup, seems the kit had the old chipset. And I think my other two 1581's have the old chipset. My 1571's may have buggy rom, too... So what the heck, why not get a Willem programmer and rectify the situation. I'll be making the purchase in a day or so here. That's when I realized, hey wait a second, doesn't the 128 have an optional software rom socket? I think this may only be the 128D, though. Can somebody confirm? So what if the core routines were small enough (16k or 32k rom size supported, I believe) to fit. Could the core run off a rom? Not sure if the 128 can boot to that rom, or if some kind of bootable floppy would have to be used to load a small program to transfer control. It may not be very feasable, but it was a cool idea for a tired mind today, so I thought I'd throw it out there. Been kinda quiet on the BBS front lately. I do appologize for my being quiet, too, as work got busy there for awhile.

[Mark Smith]

Yup the 128's all have a ROM socket, you can put large ROMs in and select which bank you want with the flick of a switch.

I've GEOS installed in mine so when it's flicked to ON the C128 boots straight into GEOS and after asking for the system disks away it goes.

So yes to your questions, you can put a ROM in, and it will "boot" from it.

What sort of core/OS/application do you have in mind ?

[David Nelson]

So yes to your questions, you can put a ROM in, and it will "boot" from it.

Sweet -- that is very good to know.

What sort of core/OS/application do you have in mind ?

I've had to pack everything up for awhile right now because I'm in the middle of moving my whole household and family. Once we get settled in our new digs, I hope to have time to experiment. My Willem programmer has been finished and is in the mail, and my power supply for it arrived yesterday. At the moment I'm not 100% sure what I'd like to put on the rom. One use that popped into mind was perhaps the software support that's necessary to get the Palm ethernet cradle hack fully functional. Although I have all the parts and instructions to do the hack, and a C128D to test it with, I don't have the time at the moment due to the move. I was just thinking way ahead of myself. Programming to the rom is something I'd like to get into. The sky is the limit.

-David

[Mark Smith]

Neat .. well do remember to keep us posted on how things go, I to would lie to know how to get stuff to execute from ROM.

Those Willem devices, they only cost about AU$120 don't they ?  Seen some on ebay and was wondering about getting one.

Oh yes, got a good book here electronics projects for the C64 C128... will post about it in a new thread :-)

[David Nelson]

Those Willem devices, they only cost about AU$120 don't they ?  Seen some on ebay and was wondering about getting one.

I'm not sure about the price conversion. The one I just purchased cost me about $90 USD, for a Willem 4.1 with a voltage modification to properly program NMOS EPROMs. For what I had in mind (the rom for the 128, and rom upgrades for the 1571/1581), this particular model was the ideal choice. Oh, I also had to buy a power supply for it, and that cost $8 from Jameco (electronics parts distributor). It arrived today (as did the power supply)! Awesome. And the software was downloaded from the website.

I started by looking on Ebay, since the prices were reasonably cheap. I noticed right away on Ebay that there appeared to be different models. I then went to www.willem.org and tried to match up the Ebay pictures with the models, so I could read more about them. There was the 3.1, 3.1 ATH, 4.0, 4.1, 4.5, PCB3B, Enhanced, and EZo!! Most of the Ebay models did NOT match up. They looked nothing like the "real" ones, so I became suspicious and very confused. I learned 3.1 and PCB3B are mostly the same, and you sometimes have to fiddle with them to get it to work properly. Worse, many people on the forum there declared these revisions "worthless" for programming EPROMS. Exactly what I wanted to do. The Ehanced was just another variation of one of those two. Not good. The 4.5 was specialized, also not really meant for what I wanted to do. So that left me with 4.0 and 4.1, which 4.1 is the newer revision. After giving myself a real headache figuring all that out, I decided to just spend a little extra for peace of mind and buy it from the source. Having learned all this, I strongly recommend against buying one off of Ebay. I'd hate to see somebody get frustrated because they ended up with the wrong board revision that wouldn't serve their needs.

It'll be several weeks (maybe a month?) before my relocation is finished and I can settle down to have a play with my projects. First test will be upgrading the rom on my 1571 and 1581's. That should get me familiar with the Willem and its software. I also picked up an EPROM blanker in case I make a mistake and need to start over. I'll let you know how easy or hard it turns out to be.

Oh yes, got a good book here electronics projects for the C64 C128... will post about it in a new thread :-)

Yes, saw that with great interest.

-David

[Mark Smith]

Hmm .. so there are some bad knock offs of the Willem programmers ?  Probably buy from them direct then.
I'm also keen on putting in the latest ROMs into my machines, then branching off and seeing what custom ROMs I can put together.  The 1571 and 1581 ROMs .. well I got impatient and bought some off of Ebay .. snag is they were all dead when I got them, so the seller is sending me some replacements, either the postman has a bad arse magnet around his neck or they are not good to start with  ... soon see, the seller seems to be a genuine sort and all so I don;t think it's going to be a big hassle :-)

You know if you like I can test your Willem progrmmer for you .... ;-)

[David Nelson]

Yeah, some of those Willem programmers on Ebay are questionnable. They seem to be based on those 3.1, PCB3B, or Enhanced schematics. And those are the ones with problems programming EPROMS. Best to pay a little extra and get the 4.1 from the source.

Were you the person who purchased a 1581 from the seller in Europe, and the chip arrived DOA? I was watching that auction and then I saw that message on the comp.sys.cbm newsgroup. That's when I decided enough, I'd do it myself. lol My Willem is packed up for our big move. It'll get unpacked by the end of September.

Stay tuned.
-David