Monitor ROMs

[Steve Gray]

Reading the WEMON manual I was impressed that it adds Commodore-like screen editing, including cursor inside quotes mode. I was also impressed with CEGMON's screen windowing commands. As a C4P user (well when it gets fixed) I wish that WEMON was available for my machine. I wish there was a combination CEGMON+WEMON monitor...

With my Commodore ColourPET and EditorROM projects (http://www.6502.org/users/sjgray/projec ... index.html) I'm trying to push the machine and to add new capabilities/features (for example support for colour, alternate keyboards, screen displays and new editor features). Back in 1981 when I got my C4P I wished it was more commodore-like, and I think in 2015 it could actually be accomplished.

What are your thoughts? Does anyone care about the monitor rom really? Are we using our OSI's just to load software/games and relive those old days or are we pushing/hacking the hardware to do more than it did back then? In other words, is there interest/demand for new firmware development or are we happy with what we have now?

Steve

[bxdanny]

The idea is intriguing, but I wonder how practical it is, considering that it would need additional address space for the ROM that is not readily available, at least not without introducing significant incompatibilities between the modified and unmodified systems. Maybe a CBM-style editor could be done simply as software that would operate through the standard vectors provided by CEGMON (and SYN600 on the C1P/Superboard).

I am assuming that it does indeed take more than 2k of space to implement. If it can be done in 2k, then a ROM version would make sense.

[Steve Gray]

On the Commodore PET the standard screen editor fits in 2k. This 2k also includes keyboard scanning and irq handling code. The WEMon monitor is actually 4k but requires some pcb mods. CEGMON is 2k and fits the windowing code in. CEGMON source is available. I think it is possible.

The osi keyboard uses an 8x8 matrix but not all positions have keys. It would be possible to wire up cursor movement and CLS/HOME keys in the unused positions to support the screen editor.

Steve

[BillO]

New development adds fire and life. It's a good thing.

All the address and data signals go to the bus. The additional code could be put on an EPROM on a card attached to the bus.

[RedskullDC]

Hi Steve, et al.

+1 to BillO's response.

Push the pedal to the metal

Cheers,
Leslie

[Mike52]

Hi all,

Would it be possible to use a 2716 or similar onboard as a minimalistic 'boot' rom. With a module plugged into the expansion socket, and some suitable code and a little hardware (programmable latch or similar) to bank switch 1 of several different rom images held in something like a 27128.

That way we could have a choice of different monitor roms selectable under software control. This would then hopefully eliminate the incompatibility problems, giving us the best of both worlds.

Regards,
Mike