View Full Version : changing text mode on a model 4

vic user
May 30th, 2005, 03:25 PM
am i able to change the text mode while using basic?

i noticed that the model 4 can use 64 characters by 40 lines, and i would love to use this for programs.


Terry Yager
May 30th, 2005, 08:36 PM
When using BASIC on the Mod IV, you're actually in Mod III emulation mode, and the 80-column display is not available, IIRC. The M4 has M3 ROMs installed, which is where BASIC lives. Of course, a clever programmer could create thier own 80-col character set using bit-addressable graphics...


vic user
May 31st, 2005, 04:40 AM
Hey Terry;

thanks for your reply.

no, the model 4 basic is in 80 columns and comes on disk, but is otherwise completely compatible with model III basic.

you can get the model III basic, and its text mode through pressing down on the break key while rebooting.

Of course, a clever programmer could create their own 80-col character set using bit-addressable graphics...

sadly that ain't me!


Terry Yager
May 31st, 2005, 07:31 AM
Right. I thought that was what you were doing, using the ROM BASIC. The disk-based version is the only one I can use on my 4P. It doesn't come with any M3 ROMs.


vic user
May 31st, 2005, 08:14 AM
wow, i had no idea the 4p was like that.

i wonder what the reasons were for not putting in the roms?

space, keeping costs down, not interested in model III anymore?


Terry Yager
May 31st, 2005, 10:32 AM
I dunno, but the other thing they left out of the 4P is the cassette port. It's a shame too, because I have access to a lot of software on tape, but I can't use it.


vic user
May 31st, 2005, 03:25 PM
what kind of rs232 connection does it have?

one like the non gate array model 4, which is a card edge type, or like the gate array model 4 which has a fully integrated rs232 port, or something completely different?


Terry Yager
May 31st, 2005, 04:25 PM
No, it has a regular female 25-pin D-shell RS-232C connector. At least they got that right.


June 1st, 2005, 10:59 PM
Of course, a clever programmer could create their own 80-col character set using bit-addressable graphics...

I think the display mode gets set way earlier, when the bios is deciding do we do basic, or load OS ? It's actually not just addressing the individual pixels, you need to be able to pop the video 'card' and monitor into a different mode.

The 4's do support some sort of dislpay switching, I notice this when I fire it up with CP/M 3, on the 64k 4, the screen scrunches, and then it spins it's wheels, but on the bank-switched 4, it loads.
This is how I keep them apart.

By the by, if any one needs a copy of the mod 4 CP/M 3, PM me, although it might be a while before I can deliver the goods, since I'm moving.


Terry Yager
June 2nd, 2005, 06:56 AM
I'm not exactly sure how it was accomplished, but the Victor/Sirus 9000 allowed you to change the screen font, using one of several fonts that came on disk, or even fonts of your own design. To do this required use of a software package called "Graphics Tool Kit", which consisted of several sub-programs including:

Grafix - the graphics extensions, line, circle, etc
Busigraf - business graphics, pie charts, etc
Chargraf - character graphics
Efont - this is the font editor used to create new fonts
Keygen - soft-key redefinition
Modcon - console modification utility used to set and save keyboard tables and character sets
GW-BASIC - gee whiz, need I say more?

From the manual:

With the Grafix Package, you can use up to ten different character sets of 128 characters each, and up to eight full screens.


Grafix can be used with any language that is capable of executing a print statement.

The fonts that came with the package were pretty nice, but I never understood why anyone would want to change from the V9K's built-in font, which is the prettiest font I've ever seen on a computer screen (although it is kinda fun to play around with designing your own characters).