Disable the 80 column card using code

[Lardo Boffin]

Hello!

Does anyone know how to disable the 80 column card using machine code?

Basically I am developing using Borland Turbo Pascal in 80 column mode but want the software I am writing to run in 40 column mode without having to exit to DOS and press keys to switch manually.

Thanks!

[Lardo Boffin]

Looks like this may do it:

IMG_4869.jpeg (2.75 MiB) Viewed 3236 times

[gunrock]

That should do it! Looks like you're having fun.

[Lardo Boffin]

I’m trying to get my head around Borland Turbo Pascal. It’s quite good!

The development environment is very advanced for the time.

[gunrock]

I used Turbo Pascal for the PC around '87. It was decent. My friend at college wrote a pretty cool game that wrote directly to Hercules video memory by mapping a 2D array overlaying those memory addresses. Fast screen updates for free!

Not possible to do that on the TMS99XX graphics architecture, of course!

[Gary C]

Used TP to write an emulator for a Digital Equipment Corporation TU58 tape drive back in the early 90's. Its still in use now.

I do remember it having the same error as the Pascal compiler on the Old PRIME mainframe I used to program on at college. As I remember, if you coded an input after a certain print command, it would put a carriage return into the input buffer such that you needed to put a second input straight after it to get it to read from the keyboard.