On Mon, 15 Aug 2016, Alexandre Souza wrote:
This is a CGA clone.
Apparently
It can work with CGA [monitors]
Presumably
and Hercules monitors/modes, and
really?
connecting a "hercules" monitor, such as a 5151 to CGA can damage the
monitor.
usually were switched by a program called MONO.COM.
such as:
MOV AX, 0002h ; Set mode to CGA B&W
Int 10h
Int 20h
MOV AX, 003h ; Set mode to CGA color
Int 10h
Int 20h
MOV AX, 0007h ; Set mode to MDA
Int 10h
Int 20h
They can be shortened a byte by using INT 3, instead of INT 20h, or
lengthened with MOV AX 4C00h Int 21h. But, since each program is going
to occupy a 512 byte sector, the difference won't matter.
or using MODE.COM:
MODE BW80
MODE CO80
MODE MONO
I Believe I have some boards like that. Possibly I have the manual and
disk.
Does THIS particular board handle BOTH CGA and MDA frequencies?
If not, telling him to connect his 5151 or "hercules" monitor, is going to
cost him a monitor.
If so, telling him to connect his 5151 or "hercules" monitor without the
right switch settings, is going to cost him a monitor.
5151 and "hercules" (MDA) monitors do not like wrong frequencies.
SERIOUSLY: connecting a 5151 or "hercules" monitor to the wrong signals
can damage it.
