*** M E M O R U M ***

I've read that the SD card image which comes with the MFX has a hidden partition ready for Hextrain. Does the image have the actual demo hiding somewhere?

I'd like to show off the demo at the Centre for Computing History in Cambridge this weekend and thought I'd ask before looking into what would be needed to get the demo installed.

The original version that Andy did is HTSD.COM I thought Dave had included that on the image.

If not it's in the hextrain archive from Andy's site, which is where I pulled it from for the original testing.

Unless I co**ed up, it will be on the first partition

Regards
Dave

Thanks. I'll take a look.

P.S. Yes it's there as "ht.com" but you have to switch the VDP first using "vdp.com" before blindly starting it.

Can you try typing

Cpmvdp ht

I tried it this morning and it works.

I think I may rename ht.com to hextrain.com to make it clear what it is.

CPMVDP is a program that Bill wrote so that you can start a COM game without having to do it “blind”

The single argument is the name of a com file (without the extension), as you’ll have seen, the program sends emulated VDP output to the VGA and starts the program.

(It is covered in the 1.1 Rev of the manual on page 131)

Regards
Dave

Whereas VDP.COM Martin wrote because he's to lazy to write the full fledeged launcher!

In theory it should work well enough in a 2 line xxxx.SUB file ie but I never needed to test it as Bill did his "proper" launcher

Marin's approach may be better if you have a very large .COM file. CPMVDP works by copying itself into high memory, then loading the new COM file beneath it, before jumping to the start of the new program. So it takes up a bit of the TPA while loading. Once the new program has started it can overwrite CPMVDP.

With Martin's approach, the switch to VDP mode is done first, then the operating system loads the new program, with the full TPA available.

This does not affect Hextrain. The COM file is fairly small. The large volume of Hextrain video data exists entirely outside of the CP/M drive images and is only accessed once the Hextrain COM file is running.