OricSCII - the Oric character set

Charset 0

The encoding used by the Oric is ASCII with a few minor differences :

There are only 96 characters in the set. This is not an error. Codes 0x80-0xFF use the same patterns as codes 0x00-0x7F and, unlike many microcomputers of its time, the Oric does not have any patterns for codes 0x00-0x1F. Those are limitations of the hardware ; they cannot be worked around in software.

Routine 0xF73F/0xF77C treats 0x7F/DEL/delete as a control character. The only way to see the solid rectangle is to write its code directly into the video RAM, for example by using POKE #BD42,127 or PLOT 10,10,#7F.

Charset 1

The second character set has even fewer possible codes because the memory area where the last 16 patterns would be, 0xBB80-0xBBFF, overlaps the text video RAM (another unfortunate feature of the hardware). Of the 80 usable codes that remain, the first 64 are used for Prestel semi-graphic characters. The others are not explicitly initialised so they are normally filled with the 0x55 value left by the RAM test routine.

A font for the Super Oric

On some displays, vertical lines appear dimmer than horizontal lines. This phenomenon is most noticeable on CRT with low vertical resolution but it also affects certain flat panel television sets. It results in poor readability, especially for light-on-dark text.

An simple remedy is to make vertical lines thicker. While this would not be easy to do within the confines of the 6 × 8 character cells of the Oric, the Super Oric has wider cells. V1.44 ROM, however, does not really take advantage of this, simply padding the original 6 × 8 font with empty columns. Here is a replacement OricSCII font for the Super Oric which makes use of the two extra columns for double-width vertical lines :

Yes, this is based on the classic arcade game font, at least for the numerals, capitals and some of the punctuation. The three screen shots below show it in action. The first is a regular Oric screen (6-wide font in 6-wide cells), the second is a simulation of a Super Oric (6-wide font in 8-wide cells) and the last is what a Super Oric screen would look like with this font (8-wide font in 8-wide cells).

Downloads :


This is http://www.teaser.fr/~amajorel/oricscii/, last modified AYM 2010-02-15.