HDB-DOS in a Rom Pak?

[R.Cade]

I have a question about Drivewire (HDB-DOS) in a Rom Pak.

 

I recently rescued a Coco3 and burned the HDB-DOS 1.4 to an EPROM, and put it in a Super Pitfall cartridge. This boots up OK, except I find it's unstable- I can't boot NitroOS, and even the RAM stress test fails on bank $03c. However, if I pull the cartridge and instead load with cassette port, it works fine.  It seems like the cartridge is interfering with RAM.  

 

Is this just a known limitation of running HDB-DOS from a Rom Pak, or do I need to modify the cartridge in some other way?

[linville]

On the CoCo, a DOS is intended to be loaded based on a signature in the ROM, whereas a game (like Super Pitfall) uses a different mechanism to autostart. I'm not 100% sure on the technical details of why HDB-DOS isn't working in your configuration, but I suspect that if you had the same ROM image loaded in a non-autostart cartridge (e.g. the Deluxe RS232) things might work better for you.

[R.Cade]

Thanks. I'm going to first try cutting the autostart line to the cart, then look and make sure the cart enable line is properly connected to the CE and OE on the EPROM.

 

[R.Cade]

Cutting the connection between 7 and 8 fixed it. Q and CART.

[Charlie_]

I have removed the chip and replaced it with a socket on a standard game cart.

Wrote HDB-DOS on chips for the various coco versions so they would work properly with drivewire.

Still have them somewhere and they worked just fine.

 

 

[MrDave]

Most disk software is not worried about the interrupt from the cart ( autostart ..ie the q signal to cart ) so you have to fix any writes to ff23 .

Also if you want the coco3 basic working properly it might be best to let it do its boot up routine and run your cart with the exec &HE010.  Formally &HC000 on coco1,2

 

Also you new pcb's for your roms !  They are cheap ..work better .. i even have some that can bank switch.allowing 32k of data for coco1,2 ... 

[YannAros]

I've designed a multibank card for my COCO2 and I tinker a bit with drivewire.

 

I've flashed "HDB-DOS 1.1D DW3" in one bank of my card and got it working, but I also have some instabilities.

Sometimes the computer freezes when loading a game and I need to go through a power cycle to bring it back and then the same game can load wihtout an issue.

 

I have a jumper to enable /disable autostart, I will give it a try.

However I'd like to know where I can find the latest HDBDOS version for Drivewire.

I've been following the links from here and only found v1.1d : https://www.cocopedia.com/wiki/index.php/Getting_Started_with_DriveWire

 

 

Edited April 25 by YannAros

[YannAros]

More details about the instability, I get sometime Error[243] in DriverWire 3 WinServer log

[YannAros]

Got v1.5 from here : https://sourceforge.net/projects/toolshed/files/ToolShed/ToolShed 2.2/

It seems to be more stable, I still see some Errors[243] but less.

Reset also really resets compared to previously where it kept previous stuff in RAM

Edited April 26 by YannAros