Writing for the XEP80

[Bee]

Wrote a basic program to add a TD line to the XEP80 in my programs.

 

 

getting a base set of tools built.

 

Thank you

 

[Mathy]

Hello Bee

 

Have you looked at the XEP80 section om my special stuff page?  (After you click on the link, you'll find three files at the top of the screen you might want to have a look at)

 

Sincerely

 

Mathy 

[Kyle22]

Lemme get this straight... You used BASIC for this? I would have used Assembler and put this in the VBI to keep updated.

BASIC? Really?

 

[Bee]

Yes - Basic because I have a bunch of things already written in basic.  I'm currently using the XEP80 driver in Sparta Dos.  I will have a stab at making a bob term Disk.

 

@Mathy Thanks I had a read through and learned a lot.

 

Thank you.

[luckybuck]

https://atariwiki.org/wiki/Wiki.jsp?page=XEP80

[Bee]

@Mathy I have down loaded Bob Term from you and the fast XEP80 handler.  When I un arc the fast driver it is a file called modual1.off?  I'm not sure how to use it.

 

Any advice?

 

Thank you

[_The Doctor__]

bobterm module files are sometimes slightly modified drivers... you can rename them to what they are, I usually leave there real names and copy the ones I am using to modulex.btm or whatever the convention is x=0,1,2,3 etc... I may be slightly off but bobterm has documentation so If you read it, chances are the good information is there.

[+Larry]

I haven't had my XEP80 out in years, but I remember that I never got past the horrible overscan issue -- I got something like 78 columns and 23+a half rows.  I remember researching it enough that I believed that the root cause was in the ROM.  Has anyone ever fixed that?  I believe that under Altirra, it is not an issue, but I'm referring to real hardware.

-Larry

[Rybags]

I can vaguely remember reading about a fix but don't remember if it was a modification of the unit itself or to a monitor.

[phaeron]

It's a combination of hardware and firmware. The hardware is limited in that it can only place vertical sync within one character row of the end of the display. Atari should have put blank rows at the beginning and end, but instead they just hugely overscanned it.

 

I ship a XEPVHOLD.COM program now with Altirra that reprograms the XEP80 for less overscan and better video timing so the display is less likely to roll on modern TVs. It shortens the character rows slightly and unfortunately cuts off descenders a bit, but that's unavoidable without reprogramming the character set ROM.