Hand-rolling a CP/M machine
cclist at sydex.com
Wed Apr 25 22:54:21 CDT 2007
On 25 Apr 2007 at 16:00, Allison wrote:
> FYI: to do it by hand all one needs is a sheet or a few of grid paper
> and a #2 graphite thingie. The order you enter the data is row for
> the low address lines (usualy 4 address lines) and the high address
> lines are the ascii value (0-127) that corosponds with the char.
If you have access to the driver disks for the Herc Graphics Plus,
there are some nice fonts in various aspect ratios there--essentially
ROM images. If you've got an old EGA card that supports 43 line
mode, there's another nice small font. If you want 7x9 EBCDIC, I've
got ROMs for that.
We were using 2716's as character generator ROMS for 80x25 displays
back in 1977 and they were plenty fast even then.
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