PCG is the abbreviation of Programmable Character Generator. 256 characters of the character generator can be defined as you like if using the PCG700.
The PCG700 was developed by HAL Laboratory for the MZ-700.
High-resolution graphics interface for the MZ-700
If your interest lies in graphics you will be well advised to this special extension device fitted to your MZ-700. It gives outstanding control over the screen display. This can be done by use of the SET / RESET command which turns on and off dots, one quarter the size of a normal character. A high-resolution interface gives you complete control over the pixels ( picture elements – dots, to you and me ! ) which make up the TV image.
This is the kind of facility which allows you to produce those fine line drawings which you have always wondered at when you have seen them at computer exhibitions ! ( It will also enable you to convert programs which are designed for the high-resolution facility of the MZ-800 for use on your MZ-700. )
The high-resolution effect can be switched on and off by commands from within your programs. Not only does it enable you to draw brilliant pictures and plot precise graphs ( 3D included ) but it also allows you to design your own character sets. As a further bonus, when not in use, it can be used as a further 2kb of RAM !
This accessory should be high on your Christmas list….
- The character generator of the MZ-700 is replaced by RAM
- The PCG700 can be controlled by hardware and software
- 256 characters of the MZ-700’s character generator can be replaced. The upper 128 characters of both character sets can be replaced – the lower parts cannot be changed.
- ou’ll find more details if you read the description of the PCG-AID utility.
- The software controller of the PCG700 uses unused I/O-ports
- The PCG700 doesn’t change any functions of the MZ-700 (except for the CG )
- No soldering is required to built in the PCG700
- The system bus remains active for further expansions
The PCG700 replaces the ROM-character generator by connecting a cable into the socket of the CG-ROM. No further RAM is necessary.
If you store another character set into the PCG700 ( like Greek, Arab, Cyrillic, Japanese, whatever ) you easily can use a text processor on your MZ-700 in this language directly.
PCG difference to a Standard-Bitmap-Graphic
There are two different graphic-modes:
Each screen dot uses a bit
Each screen dot can be set like for a bitmap-graphic, but the difference is that the character generator processes blocks of 8 x 8 bits ( 8 bytes ) in a single step.
The advantage of a bitmap-graphic is the independence of text and graphic. But it uses a special screen controlling which the MZ-700 doesn’t support. Several hardware modifications are necessary to enable the MZ-700 for this mode and the programming is problematic too.
If you want to use a bitmap-graphic you can copy the bitmap storage into the PCG700-RAM and display it by a simple control program.
Special thanks to Hideki / Japan for the translations from the PCG700 Manual